1 .\" Copyright (c) 1998-2013 Proofpoint, Inc. and its suppliers.
2 .\" All rights reserved.
3 .\" Copyright (c) 1983, 1995 Eric P. Allman. All rights reserved.
4 .\" Copyright (c) 1983, 1993
5 .\" The Regents of the University of California. All rights reserved.
7 .\" By using this file, you agree to the terms and conditions set
8 .\" forth in the LICENSE file which can be found at the top level of
9 .\" the sendmail distribution.
12 .\" $Id: op.me,v 8.759 2014-01-13 14:40:05 ca Exp $
14 .\" eqn op.me | pic | troff -me
16 .\" Define \(sc if not defined (for text output)
18 .if !c \(sc .char \(sc S
20 .\" Define \(dg as "*" for text output and create a new .DG macro
21 .\" which describes the symbol.
37 .\" Define \(dd as "#" for text output and create a new .DD macro
38 .\" which describes the symbol.
51 .eh 'SMM:08-%''Sendmail Installation and Operation Guide'
52 .oh 'Sendmail Installation and Operation Guide''SMM:08-%'
53 .\" SD is lib if sendmail is installed in /usr/lib, sbin if in /usr/sbin
55 .\" SB is bin if newaliases/mailq are installed in /usr/bin, ucb if in /usr/ucb
74 .b SENDMAIL\u\s-6TM\s0\d
77 .b "INSTALLATION AND OPERATION GUIDE"
80 This documentation is under modification.
93 .Ve $Revision: 8.759 $
96 For Sendmail Version 8.14
99 Sendmail is a trademark of Proofpoint, Inc.
100 US Patent Numbers 6865671, 6986037.
104 .i Sendmail \u\s-2TM\s0\d
105 implements a general purpose internetwork mail routing facility
108 It is not tied to any one transport protocol \*-
109 its function may be likened to a crossbar switch,
110 relaying messages from one domain into another.
112 it can do a limited amount of message header editing
113 to put the message into a format that is appropriate
114 for the receiving domain.
115 All of this is done under the control of a configuration file.
117 Due to the requirements of flexibility
120 the configuration file can seem somewhat unapproachable.
121 However, there are only a few basic configurations
123 for which standard configuration files have been supplied.
124 Most other configurations
125 can be built by adjusting an existing configuration file
130 RFC 821 (Simple Mail Transport Protocol),
131 RFC 822 (Internet Mail Headers Format),
132 RFC 974 (MX routing),
133 RFC 1123 (Internet Host Requirements),
134 RFC 1413 (Identification server),
135 RFC 1652 (SMTP 8BITMIME Extension),
136 RFC 1869 (SMTP Service Extensions),
137 RFC 1870 (SMTP SIZE Extension),
138 RFC 1891 (SMTP Delivery Status Notifications),
139 RFC 1892 (Multipart/Report),
140 RFC 1893 (Enhanced Mail System Status Codes),
141 RFC 1894 (Delivery Status Notifications),
142 RFC 1985 (SMTP Service Extension for Remote Message Queue Starting),
143 RFC 2033 (Local Message Transmission Protocol),
144 RFC 2034 (SMTP Service Extension for Returning Enhanced Error Codes),
146 RFC 2476 (Message Submission),
147 RFC 2487 (SMTP Service Extension for Secure SMTP over TLS),
148 RFC 2554 (SMTP Service Extension for Authentication),
149 RFC 2821 (Simple Mail Transfer Protocol),
150 RFC 2822 (Internet Message Format),
151 RFC 2852 (Deliver By SMTP Service Extension),
153 RFC 2920 (SMTP Service Extension for Command Pipelining).
156 is designed to work in a wider world,
157 in many cases it can be configured to exceed these protocols.
158 These cases are described herein.
163 without the need for monitoring,
164 it has a number of features
165 that may be used to monitor or adjust the operation
166 under unusual circumstances.
167 These features are described.
169 Section one describes how to do a basic
173 explains the day-to-day information you should know
174 to maintain your mail system.
175 If you have a relatively normal site,
176 these two sections should contain sufficient information
181 has information regarding the command line arguments.
183 describes some parameters that may be safely tweaked.
185 contains the nitty-gritty information about the configuration
187 This section is for masochists
188 and people who must write their own configuration file.
190 describes configuration that can be done at compile time.
191 The appendixes give a brief
192 but detailed explanation of a number of features
193 not described in the rest of the paper.
195 .sh 1 "BASIC INSTALLATION"
197 There are two basic steps to installing
199 First, you have to compile and install the binary.
202 has already been ported to your operating system
203 that should be simple.
204 Second, you must build a run-time configuration file.
207 reads when it starts up
208 that describes the mailers it knows about,
209 how to parse addresses,
210 how to rewrite the message header,
211 and the settings of various options.
212 Although the configuration file can be quite complex,
213 a configuration can usually be built
214 using an M4-based configuration language.
215 Assuming you have the standard
219 for further information.
221 The remainder of this section will describe the installation of
223 assuming you can use one of the existing configurations
224 and that the standard installation parameters are acceptable.
225 All pathnames and examples
226 are given from the root of the
230 .i /usr/src/usr.\*(SD/sendmail
231 on 4.4BSD-based systems.
233 Continue with the next section if you need/want to compile
236 If you have a running binary already on your system,
237 you should probably skip to section 1.2.
238 .sh 2 "Compiling Sendmail"
253 This will leave the binary in an appropriately named subdirectory,
256 It works for multiple object versions
257 compiled out of the same directory.
258 .sh 3 "Tweaking the Build Invocation"
260 You can give parameters on the
263 In most cases these are only used when the
265 directory is first created.
266 To restart from scratch, use
268 These commands include:
270 .ip "\-L \fIlibdirs\fP"
271 A list of directories to search for libraries.
272 .ip "\-I \fIincdirs\fP"
273 A list of directories to search for include files.
274 .ip "\-E \fIenvar\fP=\fIvalue\fP"
275 Set an environment variable to an indicated
282 .ip "\-f \fIsiteconfig\fP"
283 Read the indicated site configuration file.
284 If this parameter is not specified,
289 .i $BUILDTOOLS/Site/site.$oscf.m4
291 .i $BUILDTOOLS/Site/site.config.m4 ,
292 where $BUILDTOOLS is normally
294 and $oscf is the same name as used on the
297 See below for a description of the site configuration file.
299 Skip auto-configuration.
301 will avoid auto-detecting libraries if this is set.
302 All libraries and map definitions must be specified
303 in the site configuration file.
305 Most other parameters are passed to the
307 program; for details see
308 .i $BUILDTOOLS/README .
309 .sh 3 "Creating a Site Configuration File"
312 (This section is not yet complete.
313 For now, see the file devtools/README for details.)
314 See sendmail/README for various compilation flags that can be set.
315 .sh 3 "Tweaking the Makefile"
317 .\" .b "XXX This should all be in the Site Configuration File section."
319 supports two different formats
320 for the local (on disk) version of databases,
324 At least one of these should be defined if at all possible.
327 The ``new DBM'' format,
328 available on nearly all systems around today.
329 This was the preferred format prior to 4.4BSD.
330 It allows such complex things as multiple databases
331 and closing a currently open database.
333 The Berkeley DB package.
334 If you have this, use it.
337 multiple open databases,
338 real in-memory caching,
340 You can define this in conjunction with
343 old alias databases are read,
344 but when a new database is created it will be in NEWDB format.
346 if you have NEWDB, NDBM, and NIS defined,
347 and if the alias file name includes the substring
350 will create both new and old versions of the alias file
354 This is required because the Sun NIS/YP system
355 reads the DBM version of the alias file.
359 If neither of these are defined,
361 reads the alias file into memory on every invocation.
362 This can be slow and should be avoided.
363 There are also several methods for remote database access:
365 Lightweight Directory Access Protocol.
367 Sun's Network Information Services (formerly YP).
371 NeXT's NetInfo service.
373 Hesiod service (from Athena).
375 Other compilation flags are set in
377 and should be predefined for you
378 unless you are porting to a new environment.
381 .sh 3 "Compilation and installation"
383 After making the local system configuration described above,
384 You should be able to compile and install the system.
387 is the best approach on most systems:
393 to create a custom Makefile for your environment.
395 If you are installing in the standard places,
396 you should be able to install using
400 This should install the binary in
402 and create links from
403 /usr/\*(SB/newaliases
408 On most systems it will also format and install man pages.
409 Notice: as of version 8.12
411 will no longer be installed set-user-ID root by default.
412 If you really want to use the old method, you can specify it as target:
414 \&./Build install-set-user-id
416 .sh 2 "Configuration Files"
419 cannot operate without a configuration file.
420 The configuration defines the mail delivery mechanisms understood at this site,
422 how to forward email to remote mail systems,
423 and a number of tuning parameters.
424 This configuration file is detailed
425 in the later portion of this document.
429 configuration can be daunting at first.
430 The world is complex,
431 and the mail configuration reflects that.
432 The distribution includes an m4-based configuration package
433 that hides a lot of the complexity.
438 Our configuration files are processed by
440 to facilitate local customization;
445 distribution directory
446 contains the source files.
447 This directory contains several subdirectories:
450 Both site-dependent and site-independent descriptions of hosts.
451 These can be literal host names
454 when the hosts are gateways
455 or more general descriptions
457 .q "generic-solaris2.mc"
458 as a general description of an SMTP-connected host
462 (``M4 Configuration'')
463 are the input descriptions;
464 the output is in the corresponding
467 The general structure of these files is described below.
469 Site-dependent subdomain descriptions.
470 These are tied to the way your organization wants to do addressing.
472 .b domain/CS.Berkeley.EDU.m4
473 is our description for hosts in the CS.Berkeley.EDU subdomain.
474 These are referenced using the
481 Definitions of specific features that some particular host in your site
483 These are referenced using the
487 An example feature is
491 to read an /etc/mail/local-host-names file on startup
492 to find the set of local names).
494 Local hacks, referenced using the
499 The point of having them here is to make it clear that they smell.
503 include files that have information common to all configuration files.
504 This can be thought of as a
508 Definitions of mailers,
513 The mailer types that are known in this distribution are
519 For example, to include support for the UUCP-based mailers,
523 Definitions describing various operating system environments
524 (such as the location of support files).
525 These are referenced using the
530 Shell files used by the
533 You shouldn't have to mess with these.
535 Local UUCP connectivity information.
536 This directory has been supplanted by the mailertable feature;
537 any new configurations should use that feature to do UUCP
539 The use of this directory is deprecated.
541 If you are in a new domain
543 you will probably want to create a
545 file for your domain.
546 This consists primarily of relay definitions
547 and features you want enabled site-wide:
548 for example, Berkeley's domain definition
552 These are specific to Berkeley,
553 and should be fully-qualified internet-style domain names.
554 Please check to make certain they are reasonable for your domain.
556 Subdomains at Berkeley are also represented in the
562 is the Computer Science subdomain,
564 is the Electrical Engineering and Computer Sciences subdomain,
567 is the Sequoia 2000 subdomain.
568 You will probably have to add an entry to this directory
569 to be appropriate for your domain.
571 You will have to use or create
575 subdirectory for your hosts.
576 This is detailed in the
579 .sh 2 "Details of Installation Files"
581 This subsection describes the files that
585 .sh 3 "/usr/\*(SD/sendmail"
589 is located in /usr/\*(SD\**.
593 on 4.4BSD and newer systems;
594 many systems install it in
596 I understand it is in /usr/ucblib
597 on System V Release 4.
599 It should be set-group-ID smmsp as described in
601 For security reasons,
602 /, /usr, and /usr/\*(SD
603 should be owned by root, mode 0755\**.
605 \**Some vendors ship them owned by bin;
606 this creates a security hole that is not actually related to
608 Other important directories that should have restrictive ownerships
610 /bin, /usr/bin, /etc, /etc/mail, /usr/etc, /lib, and /usr/lib.
612 .sh 3 "/etc/mail/sendmail.cf"
614 This is the main configuration file for
617 \**Actually, the pathname varies depending on the operating system;
618 /etc/mail is the preferred directory.
619 Some older systems install it in
620 .b /usr/lib/sendmail.cf ,
621 and I've also seen it in
623 If you want to move this file,
624 add -D_PATH_SENDMAILCF=\e"/file/name\e"
625 to the flags passed to the C compiler.
626 Moving this file is not recommended:
627 other programs and scripts know of this location.
629 This is one of the two non-library file names compiled into
631 the other is /etc/mail/submit.cf.
633 \**The system libraries can reference other files;
634 in particular, system library subroutines that
636 calls probably reference
639 .i /etc/resolv.conf .
642 The configuration file is normally created
643 using the distribution files described above.
644 If you have a particularly unusual system configuration
645 you may need to create a special version.
646 The format of this file is detailed in later sections
648 .sh 3 "/etc/mail/submit.cf"
650 This is the configuration file for
652 when it is used for initial mail submission, in which case
653 it is also called ``Mail Submission Program'' (MSP)
654 in contrast to ``Mail Transfer Agent'' (MTA).
655 Starting with version 8.12,
657 uses one of two different configuration files based on its operation mode
661 For initial mail submission, i.e., if one of the options
667 is specified, submit.cf is used (if available),
668 for other operations sendmail.cf is used.
669 Details can be found in
670 .i sendmail/SECURITY .
671 submit.cf is shipped with sendmail (in cf/cf/) and is installed by default.
672 If changes to the configuration need to be made, start with
673 cf/cf/submit.mc and follow the instruction in cf/README.
674 .sh 3 "/usr/\*(SB/newaliases"
678 command should just be a link to
681 rm \-f /usr/\*(SB/newaliases
682 ln \-s /usr/\*(SD/sendmail /usr/\*(SB/newaliases
684 This can be installed in whatever search path you prefer
686 .sh 3 "/usr/\*(SB/hoststat"
690 command should just be a link to
692 in a fashion similar to
694 This command lists the status of the last mail transaction
695 with all remote hosts. The
697 flag will prevent the status display from being truncated.
698 It functions only when the
699 .b HostStatusDirectory
701 .sh 3 "/usr/\*(SB/purgestat"
703 This command is also a link to
705 It flushes expired (Timeout.hoststatus) information that is stored in the
706 .b HostStatusDirectory
708 .sh 3 "/var/spool/mqueue"
712 should be created to hold the mail queue.
713 This directory should be mode 0700
716 The actual path of this directory
722 To use multiple queues,
723 supply a value ending with an asterisk.
725 .i /var/spool/mqueue/qd*
726 will use all of the directories or symbolic links to directories
727 beginning with `qd' in
729 as queue directories.
730 Do not change the queue directory structure
731 while sendmail is running.
733 If these directories have subdirectories or symbolic links to directories
734 named `qf', `df', and `xf', then these will be used for the different
736 That is, the data files are stored in the `df' subdirectory,
737 the transcript files are stored in the `xf' subdirectory, and
738 all others are stored in the `qf' subdirectory.
740 If shared memory support is compiled in,
742 stores the available diskspace in a shared memory segment
743 to make the values readily available to all children without
744 incurring system overhead.
745 In this case, only the daemon updates the data;
746 i.e., the sendmail daemon creates the shared memory segment
747 and deletes it if it is terminated.
750 must have been compiled with support for shared memory
755 Notice: do not use the same key for
757 invocations with different queue directories
758 or different queue group declarations.
759 Access to shared memory is not controlled by locks,
760 i.e., there is a race condition when data in the shared memory is updated.
761 However, since operation of
763 does not rely on the data in the shared memory, this does not negatively
764 influence the behavior.
765 .sh 3 "/var/spool/clientmqueue"
768 .i /var/spool/clientmqueue
769 should be created to hold the mail queue.
770 This directory should be mode 0770
771 and owned by user smmsp, group smmsp.
773 The actual path of this directory
779 .sh 3 "/var/spool/mqueue/.hoststat"
781 This is a typical value for the
782 .b HostStatusDirectory
784 containing one file per host
785 that this sendmail has chatted with recently.
786 It is normally a subdirectory of
788 .sh 3 "/etc/mail/aliases*"
790 The system aliases are held in
791 .q /etc/mail/aliases .
794 which includes some aliases which
798 cp sendmail/aliases /etc/mail/aliases
799 .i "edit /etc/mail/aliases"
801 You should extend this file with any aliases that are apropos to your system.
805 looks at a database version of the files,
807 .q /etc/mail/aliases.dir
809 .q /etc/mail/aliases.pag
811 .q /etc/mail/aliases.db
812 depending on which database package you are using.
813 The actual path of this file
820 The permissions of the alias file and the database versions
821 should be 0640 to prevent local denial of service attacks
822 as explained in the top level
824 in the sendmail distribution.
825 If the permissions 0640 are used, be sure that only trusted users belong
826 to the group assigned to those files. Otherwise, files should not even
828 .sh 3 "/etc/rc or /etc/init.d/sendmail"
830 It will be necessary to start up the
832 daemon when your system reboots.
833 This daemon performs two functions:
834 it listens on the SMTP socket for connections
835 (to receive mail from a remote system)
836 and it processes the queue periodically
837 to insure that mail gets delivered when hosts come up.
839 If necessary, add the following lines to
844 in the area where it is starting up the daemons
845 on a BSD-base system,
846 or on a System-V-based system
847 in one of the startup files, typically
848 .q /etc/init.d/sendmail :
850 if [ \-f /usr/\*(SD/sendmail \-a \-f /etc/mail/sendmail.cf ]; then
851 (cd /var/spool/mqueue; rm \-f xf*)
852 /usr/\*(SD/sendmail \-bd \-q30m &
853 echo \-n ' sendmail' >/dev/console
860 commands insure that all transcript files have been removed;
861 extraneous transcript files may be left around
862 if the system goes down in the middle of processing a message.
863 The line that actually invokes
867 causes it to listen on the SMTP port,
870 causes it to run the queue every half hour.
872 Some people use a more complex startup script,
873 removing zero length qf/hf/Qf files and df files for which there is no
875 Note this is not advisable.
876 For example, see Figure 1
877 for an example of a complex script which does this clean up.
881 # remove zero length qf/hf/Qf files
882 for qffile in qf* hf* Qf*
888 echo \-n " <zero: $qffile>" > /dev/console
893 # rename tf files to be qf if the qf does not exist
896 qffile=`echo $tffile | sed 's/t/q/'`
897 if [ \-r $tffile \-a ! \-f $qffile ]
899 echo \-n " <recovering: $tffile>" > /dev/console
904 echo \-n " <extra: $tffile>" > /dev/console
909 # remove df files with no corresponding qf/hf/Qf files
912 qffile=`echo $dffile | sed 's/d/q/'`
913 hffile=`echo $dffile | sed 's/d/h/'`
914 Qffile=`echo $dffile | sed 's/d/Q/'`
915 if [ \-r $dffile \-a ! \-f $qffile \-a ! \-f $hffile \-a ! \-f $Qffile ]
917 echo \-n " <incomplete: $dffile>" > /dev/console
918 mv $dffile `echo $dffile | sed 's/d/D/'`
921 # announce files that have been saved during disaster recovery
922 for xffile in [A-Z]f*
926 echo \-n " <panic: $xffile>" > /dev/console
931 Figure 1 \(em A complex startup script
934 .sh 3 "/etc/mail/helpfile"
936 This is the help file used by the SMTP
939 It should be copied from
940 .q sendmail/helpfile :
942 cp sendmail/helpfile /etc/mail/helpfile
944 The actual path of this file
950 .sh 3 "/etc/mail/statistics"
952 If you wish to collect statistics
953 about your mail traffic,
954 you should create the file
955 .q /etc/mail/statistics :
957 cp /dev/null /etc/mail/statistics
958 chmod 0600 /etc/mail/statistics
960 This file does not grow.
961 It is printed with the program
962 .q mailstats/mailstats.c.
963 The actual path of this file
969 .sh 3 "/usr/\*(SB/mailq"
980 will print the contents of the mail queue;
982 This should be a link to /usr/\*(SD/sendmail.
986 stores its current pid in the file specified by the
988 option (default is _PATH_SENDMAILPID).
992 (which defaults to 0600) as
993 the permissions of that file
994 to prevent local denial of service attacks
995 as explained in the top level
997 in the sendmail distribution.
998 If the file already exists, then it might be necessary to
999 change the permissions accordingly, e.g.,
1001 chmod 0600 /var/run/sendmail.pid
1003 Note that as of version 8.13, this file is unlinked when
1006 As a result of this change, a script such as the following,
1007 which may have worked prior to 8.13, will no longer work:
1009 # stop & start sendmail
1010 PIDFILE=/var/run/sendmail.pid
1011 kill `head -1 $PIDFILE`
1014 because it assumes that the pidfile will still exist even
1015 after killing the process to which it refers.
1016 Below is a script which will work correctly
1017 on both newer and older versions:
1019 # stop & start sendmail
1020 PIDFILE=/var/run/sendmail.pid
1021 pid=`head -1 $PIDFILE`
1022 cmd=`tail -1 $PIDFILE`
1026 This is just an example script, it does not perform any error checks,
1027 e.g., whether the pidfile exists at all.
1030 To prevent local denial of service attacks
1031 as explained in the top level
1033 in the sendmail distribution,
1034 the permissions of map files created by
1037 The use of 0640 implies that only trusted users belong to the group
1038 assigned to those files.
1039 If those files already exist, then it might be necessary to
1040 change the permissions accordingly, e.g.,
1043 chmod 0640 *.db *.pag *.dir
1045 .sh 1 "NORMAL OPERATIONS"
1046 .sh 2 "The System Log"
1048 The system log is supported by the
1053 are logged under the
1057 \**Except on Ultrix,
1058 which does not support facilities in the syslog.
1062 Each line in the system log
1063 consists of a timestamp,
1064 the name of the machine that generated it
1065 (for logging from several machines
1066 over the local area network),
1071 \**This format may vary slightly if your vendor has changed
1074 Most messages are a sequence of
1080 The two most common lines are logged when a message is processed.
1081 The first logs the receipt of a message;
1082 there will be exactly one of these per message.
1083 Some fields may be omitted if they do not contain interesting information.
1086 The envelope sender address.
1088 The size of the message in bytes.
1090 The class (i.e., numeric precedence) of the message.
1092 The initial message priority (used for queue sorting).
1094 The number of envelope recipients for this message
1095 (after aliasing and forwarding).
1097 The message id of the message (from the header).
1099 The message body type (7BIT or 8BITMIME),
1100 as determined from the envelope.
1102 The protocol used to receive this message (e.g., ESMTP or UUCP)
1104 The daemon name from the
1105 .b DaemonPortOptions
1108 The machine from which it was received.
1110 There is also one line logged per delivery attempt
1111 (so there can be several per message if delivery is deferred
1112 or there are multiple recipients).
1115 A comma-separated list of the recipients to this mailer.
1117 The ``controlling user'', that is, the name of the user
1118 whose credentials we use for delivery.
1120 The total delay between the time this message was received
1121 and the current delivery attempt.
1123 The amount of time needed in this delivery attempt
1124 (normally indicative of the speed of the connection).
1126 The name of the mailer used to deliver to this recipient.
1128 The name of the host that actually accepted (or rejected) this recipient.
1130 The enhanced error code (RFC 2034) if available.
1132 The delivery status.
1134 Not all fields are present in all messages;
1135 for example, the relay is usually not listed for local deliveries.
1140 or an equivalent installed,
1141 you will be able to do logging.
1142 There is a large amount of information that can be logged.
1143 The log is arranged as a succession of levels.
1145 only extremely strange situations are logged.
1146 At the highest level,
1147 even the most mundane and uninteresting events
1148 are recorded for posterity.
1150 log levels under ten
1151 are considered generally
1154 are reserved for debugging purposes.
1155 Levels from 11\-64 are reserved for verbose information
1156 that some sites might want.
1158 A complete description of the log levels
1159 is given in section ``Log Level''.
1160 .sh 2 "Dumping State"
1164 to log a dump of the open files
1165 and the connection cache
1169 The results are logged at
1172 .sh 2 "The Mail Queues"
1174 Mail messages may either be delivered immediately or be held for later
1176 Held messages are placed into a holding directory called a mail queue.
1178 A mail message may be queued for these reasons:
1180 If a mail message is temporarily undeliverable, it is queued
1181 and delivery is attempted later.
1182 If the message is addressed to multiple recipients, it is queued
1183 only for those recipients to whom delivery is not immediately possible.
1185 If the SuperSafe option is set to true,
1186 all mail messages are queued while delivery is attempted.
1188 If the DeliveryMode option is set to queue-only or defer,
1189 all mail is queued, and no immediate delivery is attempted.
1191 If the load average becomes higher than the value of the QueueLA option
1196 option divided by the difference in the current load average and the
1199 is less than the priority of the message,
1200 messages are queued rather than immediately delivered.
1202 One or more addresses are marked as expensive and delivery is postponed
1203 until the next queue run or one or more address are marked as held via
1204 mailer which uses the hold mailer flag.
1206 The mail message has been marked as quarantined via a mail filter or
1208 .sh 3 "Queue Groups and Queue Directories"
1210 There are one or more mail queues.
1211 Each mail queue belongs to a queue group.
1212 There is always a default queue group that is called ``mqueue''
1213 (which is where messages go by default unless otherwise specified).
1214 The directory or directories which comprise the default queue group
1215 are specified by the QueueDirectory option.
1216 There are zero or more
1217 additional named queue groups declared using the
1219 command in the configuration file.
1221 By default, a queued message is placed in the queue group
1222 associated with the first recipient in the recipient list.
1223 A recipient address is mapped to a queue group as follows.
1224 First, if there is a ruleset called ``queuegroup'',
1225 and if this ruleset maps the address to a queue group name,
1226 then that queue group is chosen.
1227 That is, the argument for the ruleset is the recipient address
1228 and the result should be
1230 followed by the name of a queue group.
1231 Otherwise, if the mailer associated with the address specifies
1232 a queue group, then that queue group is chosen.
1233 Otherwise, the default queue group is chosen.
1235 A message with multiple recipients will be split
1236 if different queue groups are chosen
1237 by the mapping of recipients to queue groups.
1239 When a message is placed in a queue group, and the queue group has
1240 more than one queue, a queue is selected randomly.
1242 If a message with multiple recipients is placed into a queue group
1243 with the 'r' option (maximum number of recipients per message)
1244 set to a positive value
1246 and if there are more than
1249 in the message, then the message will be split into multiple messages,
1250 each of which have at most
1254 Notice: if multiple queue groups are used, do
1256 move queue files around, e.g., into a different queue directory.
1257 This may have weird effects and can cause mail not to be delivered.
1258 Queue files and directories should be treated as opaque
1259 and should not be manipulated directly.
1263 has two different ways to process the queue(s).
1264 The first one is to start queue runners after certain intervals
1265 (``normal'' queue runners),
1266 the second one is to keep queue runner processes around
1267 (``persistent'' queue runners).
1268 How to select either of these types is discussed in the appendix
1269 ``COMMAND LINE FLAGS''.
1270 Persistent queue runners have the advantage that no new processes
1271 need to be spawned at certain intervals; they just sleep for
1272 a specified time after they finished a queue run.
1273 Another advantage of persistent queue runners is that only one process
1274 belonging to a workgroup (a workgroup is a set of queue groups)
1275 collects the data for a queue run
1276 and then multiple queue runner may go ahead using that data.
1277 This can significantly reduce the disk I/O necessary to read the
1278 queue files compared to starting multiple queue runners directly.
1279 Their disadvantage is that a new queue run is only started
1280 after all queue runners belonging to a group finished their tasks.
1281 In case one of the queue runners tries delivery to a slow recipient site
1282 at the end of a queue run, the next queue run may be substantially delayed.
1283 In general this should be smoothed out due to the distribution of
1284 those slow jobs, however, for sites with small number of
1285 queue entries this might introduce noticable delays.
1286 In general, persistent queue runners are only useful for
1287 sites with big queues.
1288 .sh 3 "Manual Intervention"
1290 Under normal conditions the mail queue will be processed transparently.
1291 However, you may find that manual intervention is sometimes necessary.
1293 if a major host is down for a period of time
1294 the queue may become clogged.
1297 ought to recover gracefully when the host comes up,
1298 you may find performance unacceptably bad in the meantime.
1299 In that case you want to check the content of the queue
1300 and manipulate it as explained in the next two sections.
1301 .sh 3 "Printing the queue"
1303 The contents of the queue(s) can be printed
1307 (or by specifying the
1314 This will produce a listing of the queue id's,
1315 the size of the message,
1316 the date the message entered the queue,
1317 and the sender and recipients.
1318 If shared memory support is compiled in,
1321 can be used to print the number of entries in the queue(s),
1322 provided a process updates the data.
1323 However, as explained earlier, the output might be slightly wrong,
1324 since access to the shared memory is not locked.
1326 ``unknown number of entries''
1328 The internal counters are updated after each queue run
1329 to the correct value again.
1330 .sh 3 "Forcing the queue"
1333 should run the queue automatically at intervals.
1334 When using multiple queues,
1335 a separate process will by default be created to
1336 run each of the queues
1337 unless the queue run is initiated by a user
1338 with the verbose flag.
1339 The algorithm is to read and sort the queue,
1340 and then to attempt to process all jobs in order.
1341 When it attempts to run the job,
1343 first checks to see if the job is locked.
1344 If so, it ignores the job.
1346 There is no attempt to insure that only one queue processor
1348 since there is no guarantee that a job cannot take forever
1352 does include heuristics to try to abort jobs
1353 that are taking absurd amounts of time;
1354 technically, this violates RFC 821, but is blessed by RFC 1123).
1355 Due to the locking algorithm,
1356 it is impossible for one job to freeze the entire queue.
1358 an uncooperative recipient host
1359 or a program recipient
1361 can accumulate many processes in your system.
1363 there is no completely general way to solve this.
1366 you may find that a major host going down
1367 for a couple of days
1368 may create a prohibitively large queue.
1371 spending an inordinate amount of time
1373 This situation can be fixed by moving the queue to a temporary place
1374 and creating a new queue.
1375 The old queue can be run later when the offending host returns to service.
1378 it is acceptable to move the entire queue directory:
1381 mv mqueue omqueue; mkdir mqueue; chmod 0700 mqueue
1383 You should then kill the existing daemon
1384 (since it will still be processing in the old queue directory)
1385 and create a new daemon.
1387 To run the old mail queue, issue the following command:
1389 /usr/\*(SD/sendmail \-C /etc/mail/queue.cf \-q
1393 flag specifies an alternate configuration file
1395 which should refer to the moved queue directory
1397 O QueueDirectory=/var/spool/omqueue
1401 flag says to just run every job in the queue.
1402 You can also specify the moved queue directory on the command line
1404 /usr/\*(SD/sendmail \-oQ/var/spool/omqueue \-q
1406 but this requires that you do not have
1407 queue groups in the configuration file,
1408 because those are not subdirectories of the moved directory.
1409 See the section about ``Queue Group Declaration'' for details;
1410 you most likely need a different configuration file to correctly deal
1412 However, a proper configuration of queue groups should avoid
1413 filling up queue directories, so you shouldn't run into
1415 If you have a tendency toward voyeurism,
1418 flag to watch what is going on.
1420 When the queue is finally emptied,
1421 you can remove the directory:
1423 rmdir /var/spool/omqueue
1425 .sh 3 "Quarantined Queue Items"
1427 It is possible to "quarantine" mail messages,
1428 otherwise known as envelopes.
1429 Envelopes (queue files) are stored but not considered for delivery or
1430 display unless the "quarantine" state of the envelope is undone or
1431 delivery or display of quarantined items is requested.
1432 Quarantined messages are tagged by using a different name for the queue
1433 file, 'hf' instead of 'qf', and by adding the quarantine reason to the
1436 Delivery or display of quarantined items can be requested using the
1442 Additionally, messages already in the queue can be quarantined or
1443 unquarantined using the new
1448 sendmail -Qreason -q[!][I|R|S][matchstring]
1450 Quarantines the normal queue items matching the criteria specified by the
1451 .b "-q[!][I|R|S][matchstring]"
1452 using the reason given on the
1457 sendmail -qQ -Q[reason] -q[!][I|R|S|Q][matchstring]
1459 Change the quarantine reason for the quarantined items matching the
1460 criteria specified by the
1461 .b "-q[!][I|R|S|Q][matchstring]"
1462 using the reason given on the
1465 If there is no reason,
1466 unquarantine the matching items and make them normal queue items.
1469 flag tells sendmail to operate on quarantined items instead of normal items.
1470 .sh 2 "Disk Based Connection Information"
1473 stores a large amount of information about each remote system it
1474 has connected to in memory. It is possible to preserve some
1475 of this information on disk as well, by using the
1476 .b HostStatusDirectory
1477 option, so that it may be shared between several invocations of
1479 This allows mail to be queued immediately or skipped during a queue run if
1480 there has been a recent failure in connecting to a remote machine.
1481 Note: information about a remote system is stored in a file
1482 whose pathname consists of the components of the hostname in reverse order.
1483 For example, the information for
1486 .b com./example./host .
1487 For top-level domains like
1489 this can create a large number of subdirectories
1490 which on some filesystems can exhaust some limits.
1491 Moreover, the performance of lookups in directory with thousands of entries
1492 can be fairly slow depending on the filesystem implementation.
1494 Additionally enabling
1495 .b SingleThreadDelivery
1496 has the added effect of single-threading mail delivery to a destination.
1497 This can be quite helpful
1498 if the remote machine is running an SMTP server that is easily overloaded
1499 or cannot accept more than a single connection at a time,
1500 but can cause some messages to be punted to a future queue run.
1503 hosts, so setting this because you have one machine on site
1504 that runs some software that is easily overrun
1505 can cause mail to other hosts to be slowed down.
1506 If this option is set,
1507 you probably want to set the
1509 option as well and run the queue fairly frequently;
1510 this way jobs that are skipped because another
1512 is talking to the same host will be tried again quickly
1513 rather than being delayed for a long time.
1515 The disk based host information is stored in a subdirectory of the
1520 \**This is the usual value of the
1521 .b HostStatusDirectory
1523 it can, of course, go anywhere you like in your filesystem.
1525 Removing this directory and its subdirectories has an effect similar to
1528 command and is completely safe.
1531 only removes expired (Timeout.hoststatus) data.
1532 The information in these directories can
1535 command, which will indicate the host name, the last access, and the
1536 status of that access.
1537 An asterisk in the left most column indicates that a
1539 process currently has the host locked for mail delivery.
1541 The disk based connection information is treated the same way as memory based
1542 connection information for the purpose of timeouts.
1543 By default, information about host failures is valid for 30 minutes.
1544 This can be adjusted with
1546 .b Timeout.hoststatus
1549 The connection information stored on disk may be expired at any time
1552 command or by invoking sendmail with the
1555 The connection information may be viewed with the
1557 command or by invoking sendmail with the
1560 .sh 2 "The Service Switch"
1562 The implementation of certain system services
1563 such as host and user name lookup
1564 is controlled by the service switch.
1565 If the host operating system supports such a switch,
1566 and sendmail knows about it,
1568 will use the native version.
1569 Ultrix, Solaris, and DEC OSF/1 are examples of such systems\**.
1571 \**HP-UX 10 has service switch support,
1572 but since the APIs are apparently not available in the libraries
1574 does not use the native service switch in this release.
1577 If the underlying operating system does not support a service switch
1578 (e.g., SunOS 4.X, HP-UX, BSD)
1581 will provide a stub implementation.
1583 .b ServiceSwitchFile
1584 option points to the name of a file that has the service definitions.
1585 Each line has the name of a service
1586 and the possible implementations of that service.
1587 For example, the file:
1594 to look for hosts in the Domain Name System first.
1595 If the requested host name is not found, it tries local files,
1596 and if that fails it tries NIS.
1597 Similarly, when looking for aliases
1598 it will try the local files first followed by NIS.
1602 must access MX records for correct operation, it will use
1603 DNS if it is configured in the
1604 .b ServiceSwitchFile
1610 will not avoid DNS lookups even if a host can be found
1613 Service switches are not completely integrated.
1614 For example, despite the fact that the host entry listed in the above example
1615 specifies to look in NIS,
1616 on SunOS this won't happen because the system implementation of
1617 .i gethostbyname \|(3)
1618 doesn't understand this.
1619 .sh 2 "The Alias Database"
1621 After recipient addresses are read from the SMTP connection
1623 they are parsed by ruleset 0,
1624 which must resolve to a
1630 If the flags selected by the
1637 part of the triple is looked up as the key
1638 (i.e., the left hand side)
1639 in the alias database.
1640 If there is a match, the address is deleted from the send queue
1641 and all addresses on the right hand side of the alias
1642 are added in place of the alias that was found.
1643 This is a recursive operation,
1644 so aliases found in the right hand side of the alias
1645 are similarly expanded.
1647 The alias database exists in two forms.
1649 maintained in the file
1650 .i /etc/mail/aliases.
1651 The aliases are of the form
1653 name: name1, name2, ...
1655 Only local names may be aliased;
1658 eric@prep.ai.MIT.EDU: eric@CS.Berkeley.EDU
1660 will not have the desired effect
1661 (except on prep.ai.MIT.EDU,
1662 and they probably don't want me)\**.
1664 \**Actually, any mailer that has the `A' mailer flag set
1665 will permit aliasing;
1666 this is normally limited to the local mailer.
1668 Aliases may be continued by starting any continuation lines
1669 with a space or a tab or by putting a backslash directly before
1671 Blank lines and lines beginning with a sharp sign
1676 The second form is processed by the
1681 package does not work.
1683 or the Berkeley DB library.
1684 This form is in the file
1685 .i /etc/mail/aliases.db
1688 .i /etc/mail/aliases.dir
1690 .i /etc/mail/aliases.pag
1692 This is the form that
1694 actually uses to resolve aliases.
1695 This technique is used to improve performance.
1697 The control of search order is actually set by the service switch.
1698 Essentially, the entry
1700 O AliasFile=switch:aliases
1702 is always added as the first alias entry;
1703 also, the first alias file name without a class
1707 will be used as the name of the file for a ``files'' entry
1708 in the aliases switch.
1709 For example, if the configuration file contains
1711 O AliasFile=/etc/mail/aliases
1713 and the service switch contains
1715 aliases nis files nisplus
1717 then aliases will first be searched in the NIS database,
1718 then in /etc/mail/aliases,
1719 then in the NIS+ database.
1724 For example, the specification:
1726 O AliasFile=/etc/mail/aliases
1727 O AliasFile=nis:mail.aliases@my.nis.domain
1729 will first search the /etc/mail/aliases file
1730 and then the map named
1734 Warning: if you build your own
1737 be sure to provide the
1741 to map upper case letters in the keys to lower case;
1742 otherwise, aliases with upper case letters in their names
1743 won't match incoming addresses.
1745 Additional flags can be added after the colon
1748 line \(em for example:
1750 O AliasFile=nis:\-N mail.aliases@my.nis.domain
1752 will search the appropriate NIS map and always include null bytes in the key.
1755 O AliasFile=nis:\-f mail.aliases@my.nis.domain
1757 will prevent sendmail from downcasing the key before the alias lookup.
1758 .sh 3 "Rebuilding the alias database"
1764 version of the database
1765 may be rebuilt explicitly by executing the command
1769 This is equivalent to giving
1775 /usr/\*(SD/sendmail \-bi
1778 If you have multiple aliases databases specified,
1781 flag rebuilds all the database types it understands
1782 (for example, it can rebuild NDBM databases but not NIS databases).
1783 .sh 3 "Potential problems"
1785 There are a number of problems that can occur
1786 with the alias database.
1787 They all result from a
1789 process accessing the DBM version
1790 while it is only partially built.
1791 This can happen under two circumstances:
1792 One process accesses the database
1793 while another process is rebuilding it,
1794 or the process rebuilding the database dies
1795 (due to being killed or a system crash)
1796 before completing the rebuild.
1798 Sendmail has three techniques to try to relieve these problems.
1799 First, it ignores interrupts while rebuilding the database;
1800 this avoids the problem of someone aborting the process
1801 leaving a partially rebuilt database.
1803 it locks the database source file during the rebuild \(em
1804 but that may not work over NFS or if the file is unwritable.
1806 at the end of the rebuild
1807 it adds an alias of the form
1811 (which is not normally legal).
1814 will access the database,
1815 it checks to insure that this entry exists\**.
1819 option is required in the configuration
1820 for this action to occur.
1821 This should normally be specified.
1825 If an error occurs on sending to a certain address,
1829 will look for an alias
1832 to receive the errors.
1833 This is typically useful
1835 where the submitter of the list
1836 has no control over the maintenance of the list itself;
1837 in this case the list maintainer would be the owner of the list.
1840 unix-wizards: eric@ucbarpa, wnj@monet, nosuchuser,
1842 owner-unix-wizards: unix-wizards-request
1843 unix-wizards-request: eric@ucbarpa
1847 to get the error that will occur
1848 when someone sends to
1850 due to the inclusion of
1854 List owners also cause the envelope sender address to be modified.
1855 The contents of the owner alias are used if they point to a single user,
1856 otherwise the name of the alias itself is used.
1857 For this reason, and to obey Internet conventions,
1860 address normally points at the
1862 address; this causes messages to go out with the typical Internet convention
1865 as the return address.
1866 .sh 2 "User Information Database"
1868 This option is deprecated, use virtusertable and genericstable instead
1871 If you have a version of
1873 with the user information database
1875 and you have specified one or more databases using the
1878 the databases will be searched for a
1881 If found, the mail will be sent to the specified address.
1882 .sh 2 "Per-User Forwarding (.forward Files)"
1884 As an alternative to the alias database,
1885 any user may put a file with the name
1887 in his or her home directory.
1888 If this file exists,
1890 redirects mail for that user
1891 to the list of addresses listed in the .forward file.
1892 Note that aliases are fully expanded before forward files are referenced.
1893 For example, if the home directory for user
1895 has a .forward file with contents:
1900 then any mail arriving for
1902 will be redirected to the specified accounts.
1904 Actually, the configuration file defines a sequence of filenames to check.
1905 By default, this is the user's .forward file,
1906 but can be defined to be more generally using the
1910 you will have to inform your user base of the change;
1911 \&.forward is pretty well incorporated into the collective subconscious.
1912 .sh 2 "Special Header Lines"
1914 Several header lines have special interpretations
1915 defined by the configuration file.
1916 Others have interpretations built into
1918 that cannot be changed without changing the code.
1919 These built-ins are described here.
1922 If errors occur anywhere during processing,
1923 this header will cause error messages to go to
1924 the listed addresses.
1925 This is intended for mailing lists.
1927 The Errors-To: header was created in the bad old days
1928 when UUCP didn't understand the distinction between an envelope and a header;
1929 this was a hack to provide what should now be passed
1930 as the envelope sender address.
1932 It is only used if the
1936 The Errors-To: header is officially deprecated
1937 and will go away in a future release.
1938 .sh 3 "Apparently-To:"
1940 RFC 822 requires at least one recipient field
1941 (To:, Cc:, or Bcc: line)
1943 If a message comes in with no recipients listed in the message
1946 will adjust the header based on the
1947 .q NoRecipientAction
1949 One of the possible actions is to add an
1951 header line for any recipients it is aware of.
1953 The Apparently-To: header is non-standard
1954 and is both deprecated and strongly discouraged.
1957 The Precedence: header can be used as a crude control of message priority.
1958 It tweaks the sort order in the queue
1959 and can be configured to change the message timeout values.
1960 The precedence of a message also controls how
1961 delivery status notifications (DSNs)
1962 are processed for that message.
1963 .sh 2 "IDENT Protocol Support"
1966 supports the IDENT protocol as defined in RFC 1413.
1967 Note that the RFC states
1968 a client should wait at least 30 seconds for a response.
1969 The default Timeout.ident is 5 seconds
1970 as many sites have adopted the practice of dropping IDENT queries.
1971 This has lead to delays processing mail.
1972 Although this enhances identification
1973 of the author of an email message
1974 by doing a ``call back'' to the originating system to include
1975 the owner of a particular TCP connection
1977 it is in no sense perfect;
1978 a determined forger can easily spoof the IDENT protocol.
1979 The following description is excerpted from RFC 1413:
1982 6. Security Considerations
1984 The information returned by this protocol is at most as trustworthy
1985 as the host providing it OR the organization operating the host. For
1986 example, a PC in an open lab has few if any controls on it to prevent
1987 a user from having this protocol return any identifier the user
1988 wants. Likewise, if the host has been compromised the information
1989 returned may be completely erroneous and misleading.
1991 The Identification Protocol is not intended as an authorization or
1992 access control protocol. At best, it provides some additional
1993 auditing information with respect to TCP connections. At worst, it
1994 can provide misleading, incorrect, or maliciously incorrect
1997 The use of the information returned by this protocol for other than
1998 auditing is strongly discouraged. Specifically, using Identification
1999 Protocol information to make access control decisions - either as the
2000 primary method (i.e., no other checks) or as an adjunct to other
2001 methods may result in a weakening of normal host security.
2003 An Identification server may reveal information about users,
2004 entities, objects or processes which might normally be considered
2005 private. An Identification server provides service which is a rough
2006 analog of the CallerID services provided by some phone companies and
2007 many of the same privacy considerations and arguments that apply to
2008 the CallerID service apply to Identification. If you wouldn't run a
2009 "finger" server due to privacy considerations you may not want to run
2013 In some cases your system may not work properly with IDENT support
2014 due to a bug in the TCP/IP implementation.
2015 The symptoms will be that for some hosts
2016 the SMTP connection will be closed
2018 If this is true or if you do not want to use IDENT,
2019 you should set the IDENT timeout to zero;
2020 this will disable the IDENT protocol.
2023 The complete list of arguments to
2025 is described in detail in Appendix A.
2026 Some important arguments are described here.
2027 .sh 2 "Queue Interval"
2029 The amount of time between forking a process
2030 to run through the queue is defined by the
2033 If you run with delivery mode set to
2037 this can be relatively large, since it will only be relevant
2038 when a host that was down comes back up.
2041 mode it should be relatively short,
2042 since it defines the maximum amount of time that a message
2043 may sit in the queue.
2044 (See also the MinQueueAge option.)
2046 RFC 1123 section 5.3.1.1 says that this value should be at least 30 minutes
2047 (although that probably doesn't make sense if you use ``queue-only'' mode).
2049 Notice: the meaning of the interval time depends on whether normal
2050 queue runners or persistent queue runners are used.
2051 For the former, it is the time between subsequent starts of a queue run.
2052 For the latter, it is the time sendmail waits after a persistent queue
2053 runner has finished its work to start the next one.
2054 Hence for persistent queue runners this interval should be very low,
2055 typically no more than two minutes.
2058 If you allow incoming mail over an IPC connection,
2059 you should have a daemon running.
2060 This should be set by your
2069 flag may be combined in one call:
2071 /usr/\*(SD/sendmail \-bd \-q30m
2074 An alternative approach is to invoke sendmail from
2078 flags to ask sendmail to speak SMTP on its standard input and output
2080 This works and allows you to wrap
2082 in a TCP wrapper program,
2083 but may be a bit slower since the configuration file
2084 has to be re-read on every message that comes in.
2085 If you do this, you still need to have a
2087 running to flush the queue:
2089 /usr/\*(SD/sendmail \-q30m
2091 .sh 2 "Forcing the Queue"
2093 In some cases you may find that the queue has gotten clogged for some reason.
2094 You can force a queue run
2097 flag (with no value).
2098 It is entertaining to use the
2101 when this is done to watch what happens:
2103 /usr/\*(SD/sendmail \-q \-v
2106 You can also limit the jobs to those with a particular queue identifier,
2107 recipient, sender, quarantine reason, or queue group
2108 using one of the queue modifiers.
2111 restricts the queue run to jobs that have the string
2113 somewhere in one of the recipient addresses.
2116 limits the run to particular senders,
2118 limits it to particular queue identifiers, and
2120 limits it to particular quarantined reasons and only operated on
2121 quarantined queue items, and
2123 limits it to a particular queue group.
2124 The named queue group will be run even if it is set to have 0 runners.
2125 You may also place an
2135 to indicate that jobs are limited to not including a particular queue
2136 identifier, recipient or sender.
2139 limits the queue run to jobs that do not have the string
2141 somewhere in one of the recipient addresses.
2142 Should you need to terminate the queue jobs currently active then a SIGTERM
2143 to the parent of the process (or processes) will cleanly stop the jobs.
2146 There are a fairly large number of debug flags
2149 Each debug flag has a category and a level.
2150 Higher levels increase the level of debugging activity;
2151 in most cases, this means to print out more information.
2152 The convention is that levels greater than nine are
2155 they print out so much information that you wouldn't normally
2156 want to see them except for debugging that particular piece of code.
2160 run a production sendmail server in debug mode.
2161 Many of the debug flags will result in debug output being sent over the
2162 SMTP channel unless the option
2165 This will confuse many mail programs.
2166 However, for testing purposes, it can be useful
2167 when sending mail manually via
2168 telnet to the port you are using while debugging.
2170 A debug category is either an integer, like 42,
2171 or a name, like ANSI.
2172 You can specify a range of numeric debug categories
2173 using the syntax 17-42.
2174 You can specify a set of named debug categories using
2181 are supported in these glob patterns.
2183 Debug flags are set using the
2188 .ta \w'debug-categories:M 'u
2189 debug-flag: \fB\-d\fP debug-list
2190 debug-list: debug-option [ , debug-option ]*
2191 debug-option: debug-categories [ . debug-level ]
2192 debug-categories: integer | integer \- integer | category-pattern
2193 category-pattern: [a-zA-Z_*?][a-zA-Z0-9_*?]*
2194 debug-level: integer
2196 where spaces are for reading ease only.
2199 \-d12 Set category 12 to level 1
2200 \-d12.3 Set category 12 to level 3
2201 \-d3\-17 Set categories 3 through 17 to level 1
2202 \-d3\-17.4 Set categories 3 through 17 to level 4
2203 \-dANSI Set category ANSI to level 1
2204 \-dsm_trace_*.3 Set all named categories matching sm_trace_* to level 3
2206 For a complete list of the available debug flags
2207 you will have to look at the code
2210 file in the sendmail distribution
2211 (they are too dynamic to keep this document up to date).
2212 For a list of named debug categories in the sendmail binary, use
2214 ident /usr/sbin/sendmail | grep Debug
2216 .sh 2 "Changing the Values of Options"
2218 Options can be overridden using the
2225 /usr/\*(SD/sendmail \-oT2m
2229 (timeout) option to two minutes
2231 the equivalent line using the long option name is
2233 /usr/\*(SD/sendmail -OTimeout.queuereturn=2m
2236 Some options have security implications.
2237 Sendmail allows you to set these,
2238 but relinquishes its set-user-ID or set-group-ID permissions thereafter\**.
2240 \**That is, it sets its effective uid to the real uid;
2241 thus, if you are executing as root,
2242 as from root's crontab file or during system startup
2243 the root permissions will still be honored.
2245 .sh 2 "Trying a Different Configuration File"
2247 An alternative configuration file
2248 can be specified using the
2252 /usr/\*(SD/sendmail \-Ctest.cf \-oQ/tmp/mqueue
2254 uses the configuration file
2256 instead of the default
2257 .i /etc/mail/sendmail.cf.
2263 in the current directory.
2266 gives up set-user-ID root permissions
2267 (if it has been installed set-user-ID root)
2268 when you use this flag, so it is common to use a publicly writable directory
2270 as the queue directory (QueueDirectory or Q option) while testing.
2271 .sh 2 "Logging Traffic"
2273 Many SMTP implementations do not fully implement the protocol.
2274 For example, some personal computer based SMTPs
2275 do not understand continuation lines in reply codes.
2276 These can be very hard to trace.
2277 If you suspect such a problem, you can set traffic logging using the
2282 /usr/\*(SD/sendmail \-X /tmp/traffic \-bd
2284 will log all traffic in the file
2287 This logs a lot of data very quickly and should
2290 during normal operations.
2291 After starting up such a daemon,
2292 force the errant implementation to send a message to your host.
2293 All message traffic in and out of
2295 including the incoming SMTP traffic,
2296 will be logged in this file.
2297 .sh 2 "Testing Configuration Files"
2299 When you build a configuration table,
2300 you can do a certain amount of testing
2310 sendmail \-bt \-Ctest.cf
2312 which would read the configuration file
2314 and enter test mode.
2316 you enter lines of the form:
2322 is the rewriting set you want to use
2325 is an address to apply the set to.
2326 Test mode shows you the steps it takes
2328 finally showing you the address it ends up with.
2329 You may use a comma separated list of rwsets
2330 for sequential application of rules to an input.
2333 3,1,21,4 monet:bollard
2335 first applies ruleset three to the input
2337 Ruleset one is then applied to the output of ruleset three,
2338 followed similarly by rulesets twenty-one and four.
2340 If you need more detail,
2341 you can also use the
2343 flag to turn on more debugging.
2346 sendmail \-bt \-d21.99
2348 turns on an incredible amount of information;
2349 a single word address
2350 is probably going to print out several pages worth of information.
2352 You should be warned that internally,
2354 applies ruleset 3 to all addresses.
2356 you will have to do that manually.
2357 For example, older versions allowed you to use
2359 0 bruce@broadcast.sony.com
2361 This version requires that you use:
2363 3,0 bruce@broadcast.sony.com
2367 some other syntaxes are available in test mode:
2372 to have the indicated
2374 This is useful when debugging rules that use the
2384 dumps the contents of the indicated ruleset.
2386 is equivalent to the command-line flag.
2388 Version 8.9 introduced more features:
2391 shows a help message.
2393 display the known mailers.
2395 print the value of macro m.
2397 print the contents of class c.
2399 returns the MX records for `host'.
2401 parse address, returning the value of
2403 and the parsed address.
2404 .ip /try\ mailer\ addr
2405 rewrite address into the form it will have when
2406 presented to the indicated mailer.
2407 .ip /tryflags\ flags
2408 set flags used by parsing. The flags can be `H' for
2409 Header or `E' for Envelope, and `S' for Sender or `R'
2410 for Recipient. These can be combined, `HR' sets
2411 flags for header recipients.
2412 .ip /canon\ hostname
2413 try to canonify hostname.
2414 .ip /map\ mapname\ key
2415 look up `key' in the indicated `mapname'.
2417 quit address test mode.
2419 .sh 2 "Persistent Host Status Information"
2422 .b HostStatusDirectory
2424 information about the status of hosts is maintained on disk
2425 and can thus be shared between different instantiations of
2427 The status of the last connection with each remote host
2428 may be viewed with the command:
2432 This information may be flushed with the command:
2436 Flushing the information prevents new
2438 processes from loading it,
2439 but does not prevent existing processes from using the status information
2440 that they already have.
2443 There are a number of configuration parameters
2444 you may want to change,
2445 depending on the requirements of your site.
2446 Most of these are set
2447 using an option in the configuration file.
2450 .q "O Timeout.queuereturn=5d"
2452 .q Timeout.queuereturn
2457 Most of these options have appropriate defaults for most sites.
2459 sites having very high mail loads may find they need to tune them
2460 as appropriate for their mail load.
2462 sites experiencing a large number of small messages,
2463 many of which are delivered to many recipients,
2464 may find that they need to adjust the parameters
2465 dealing with queue priorities.
2470 had single character option names.
2472 options have long (multi-character names).
2473 Although old short names are still accepted,
2474 most new options do not have short equivalents.
2476 This section only describes the options you are most likely
2484 All time intervals are set
2485 using a scaled syntax.
2488 represents ten minutes, whereas
2490 represents two and a half hours.
2491 The full set of scales is:
2500 .sh 3 "Queue interval"
2504 flag specifies how often a sub-daemon will run the queue.
2505 This is typically set to between fifteen minutes and one hour.
2506 If not set, or set to zero,
2507 the queue will not be run automatically.
2508 RFC 1123 section 5.3.1.1 recommends that this be at least 30 minutes.
2509 Should you need to terminate the queue jobs currently active then a SIGTERM
2510 to the parent of the process (or processes) will cleanly stop the jobs.
2511 .sh 3 "Read timeouts"
2513 Timeouts all have option names
2514 .q Timeout.\fIsuboption\fP .
2515 Most of these control SMTP operations.
2518 their default values, and the minimum values
2519 allowed by RFC 2821 section 4.5.3.2 (or RFC 1123 section 5.3.2) are:
2522 The time to wait for an SMTP connection to open
2527 If zero, uses the kernel default.
2528 In no case can this option extend the timeout
2529 longer than the kernel provides, but it can shorten it.
2530 This is to get around kernels that provide an absurdly long connection timeout
2531 (90 minutes in one case).
2535 except it applies only to the initial attempt to connect to a host
2538 The concept is that this should be very short (a few seconds);
2539 hosts that are well connected and responsive will thus be serviced immediately.
2540 Hosts that are slow will not hold up other deliveries in the initial
2544 The overall timeout waiting for all connection for a single delivery
2546 If 0, no overall limit is applied.
2547 This can be used to restrict the total amount of time trying to connect to
2548 a long list of host that could accept an e-mail for the recipient.
2549 This timeout does not apply to
2551 i.e., if the time is exhausted, the
2555 The wait for the initial 220 greeting message
2558 The wait for a reply from a HELO or EHLO command
2560 This may require a host name lookup, so
2561 five minutes is probably a reasonable minimum.
2563 The wait for a reply from a MAIL command
2566 The wait for a reply from a RCPT command
2569 because it could be pointing at a list
2570 that takes a long time to expand
2573 The wait for a reply from a DATA command
2575 .ip datablock\(dg\(dd
2576 The wait for reading a data block
2577 (that is, the body of the message).
2579 This should be long because it also applies to programs
2582 which have no guarantee of promptness.
2584 The wait for a reply from the dot terminating a message.
2586 If this is shorter than the time actually needed
2587 for the receiver to deliver the message,
2588 duplicates will be generated.
2589 This is discussed in RFC 1047.
2591 The wait for a reply from a RSET command
2594 The wait for a reply from a QUIT command
2597 The wait for a reply from miscellaneous (but short) commands
2598 such as NOOP (no-operation) and VERB (go into verbose mode).
2602 the time to wait for another command.
2605 The timeout waiting for a reply to an IDENT query
2606 [5s\**, unspecified].
2608 \**On some systems the default is zero to turn the protocol off entirely.
2611 The wait for a reply to an LMTP LHLO command
2614 The timeout for a reply in an SMTP AUTH dialogue
2617 The timeout for a reply to an SMTP STARTTLS command and the TLS handshake
2620 The timeout for opening .forward and :include: files [60s, none].
2622 The timeout for a complete control socket transaction to complete [2m, none].
2624 How long status information about a host
2626 will be cached before it is considered stale
2628 .ip resolver.retrans\(dd
2630 retransmission time interval
2634 .i Timeout.resolver.retrans.first
2636 .i Timeout.resolver.retrans.normal .
2637 .ip resolver.retrans.first\(dd
2639 retransmission time interval
2641 for the first attempt to
2644 .ip resolver.retrans.normal\(dd
2646 retransmission time interval
2648 for all resolver lookups
2649 except the first delivery attempt
2651 .ip resolver.retry\(dd
2653 to retransmit a resolver query.
2655 .i Timeout.resolver.retry.first
2657 .i Timeout.resolver.retry.normal
2659 .ip resolver.retry.first\(dd
2661 to retransmit a resolver query
2662 for the first attempt
2663 to deliver a message
2665 .ip resolver.retry.normal\(dd
2667 to retransmit a resolver query
2668 for all resolver lookups
2669 except the first delivery attempt
2672 For compatibility with old configuration files,
2676 all the timeouts marked with
2678 (\(dg) are set to the indicated value.
2679 All but those marked with
2681 (\(dd) apply to client SMTP.
2683 For example, the lines:
2685 O Timeout.command=25m
2686 O Timeout.datablock=3h
2688 sets the server SMTP command timeout to 25 minutes
2689 and the input data block timeout to three hours.
2690 .sh 3 "Message timeouts"
2692 After sitting in the queue for a few days,
2693 an undeliverable message will time out.
2694 This is to insure that at least the sender is aware
2695 of the inability to send a message.
2696 The timeout is typically set to five days.
2697 It is sometimes considered convenient to also send a warning message
2698 if the message is in the queue longer than a few hours
2699 (assuming you normally have good connectivity;
2700 if your messages normally took several hours to send
2701 you wouldn't want to do this because it wouldn't be an unusual event).
2702 These timeouts are set using the
2703 .b Timeout.queuereturn
2705 .b Timeout.queuewarn
2706 options in the configuration file
2707 (previously both were set using the
2711 If the message is submitted using the
2715 warning messages will only be sent if
2718 The queuereturn and queuewarn timeouts
2719 can be further qualified with a tag based on the Precedence: field
2723 (indicating a positive non-zero precedence),
2725 (indicating a zero precedence), or
2727 (indicating negative precedences).
2728 For example, setting
2729 .q Timeout.queuewarn.urgent=1h
2730 sets the warning timeout for urgent messages only
2732 The default if no precedence is indicated
2733 is to set the timeout for all precedences.
2734 If the message has a normal (default) precedence
2735 and it is a delivery status notification (DSN),
2736 .b Timeout.queuereturn.dsn
2738 .b Timeout.queuewarn.dsn
2739 can be used to give an alternative warn and return time
2741 The value "now" can be used for
2742 -O Timeout.queuereturn
2743 to return entries immediately during a queue run,
2744 e.g., to bounce messages independent of their time in the queue.
2746 Since these options are global,
2747 and since you cannot know
2749 how long another host outside your domain will be down,
2750 a five day timeout is recommended.
2751 This allows a recipient to fix the problem even if it occurs
2752 at the beginning of a long weekend.
2753 RFC 1123 section 5.3.1.1 says that this parameter
2754 should be ``at least 4\-5 days''.
2757 .b Timeout.queuewarn
2758 value can be piggybacked on the
2760 option by indicating a time after which
2761 a warning message should be sent;
2762 the two timeouts are separated by a slash.
2763 For example, the line
2767 causes email to fail after five days,
2768 but a warning message will be sent after four hours.
2769 This should be large enough that the message will have been tried
2771 .sh 2 "Forking During Queue Runs"
2779 will fork before each individual message
2780 while running the queue.
2781 This option was used with earlier releases to prevent
2783 from consuming large amounts of memory.
2784 It should no longer be necessary with
2791 will keep track of hosts that are down during a queue run,
2792 which can improve performance dramatically.
2798 cannot use connection caching.
2799 .sh 2 "Queue Priorities"
2801 Every message is assigned a priority when it is first instantiated,
2802 consisting of the message size (in bytes)
2803 offset by the message class
2804 (which is determined from the Precedence: header)
2806 .q "work class factor"
2807 and the number of recipients times the
2808 .q "work recipient factor."
2809 The priority is used to order the queue.
2810 Higher numbers for the priority mean that the message will be processed later
2811 when running the queue.
2813 The message size is included so that large messages are penalized
2814 relative to small messages.
2815 The message class allows users to send
2817 messages by including a
2819 field in their message;
2820 the value of this field is looked up in the
2822 lines of the configuration file.
2823 Since the number of recipients affects the amount of load a message presents
2825 this is also included into the priority.
2827 The recipient and class factors
2828 can be set in the configuration file using the
2836 options respectively.
2837 They default to 30000 (for the recipient factor)
2839 (for the class factor).
2840 The initial priority is:
2842 pri = msgsize - (class times bold ClassFactor) + (nrcpt times bold RecipientFactor)
2844 (Remember, higher values for this parameter actually mean
2845 that the job will be treated with lower priority.)
2847 The priority of a job can also be adjusted each time it is processed
2848 (that is, each time an attempt is made to deliver it)
2850 .q "work time factor,"
2856 This is added to the priority,
2857 so it normally decreases the precedence of the job,
2858 on the grounds that jobs that have failed many times
2859 will tend to fail again in the future.
2862 option defaults to 90000.
2863 .sh 2 "Load Limiting"
2866 can be asked to queue (but not deliver) mail
2867 if the system load average gets too high using the
2872 When the load average exceeds the value of the
2874 option, the delivery mode is set to
2880 option divided by the difference in the current load average and the
2883 is less than the priority of the message \(em
2884 that is, the message is queued iff:
2886 pri > { bold QueueFactor } over { LA - { bold QueueLA } + 1 }
2890 option defaults to 600000,
2891 so each point of load average is worth 600000 priority points
2892 (as described above).
2894 For drastic cases, the
2898 option defines a load average at which
2900 will refuse to accept network connections.
2901 Locally generated mail, i.e., mail which is not submitted via SMTP
2902 (including incoming UUCP mail),
2904 Notice that the MSP submits mail to the MTA via SMTP, and hence
2905 mail will be queued in the client queue in such a case.
2906 Therefore it is necessary to run the client mail queue periodically.
2907 .sh 2 "Resource Limits"
2910 has several parameters to control resource usage.
2911 Besides those mentionted in the previous section, there are at least
2912 .b MaxDaemonChildren ,
2913 .b ConnectionRateThrottle ,
2914 .b MaxQueueChildren ,
2916 .b MaxRunnersPerQueue .
2917 The latter two limit the number of
2919 processes that operate on the queue.
2920 These are discussed in the section
2921 ``Queue Group Declaration''.
2922 The former two can be used to limit the number of incoming connections.
2923 Their appropriate values depend on the host operating system and
2924 the hardware, e.g., amount of memory.
2925 In many situations it might be useful to set limits to prevent
2928 processes, however, these limits can be abused to mount a
2929 denial of service attack.
2931 .b MaxDaemonChildren=10
2932 then an attacker needs to open only 10 SMTP sessions to the server,
2933 leave them idle for most of the time,
2934 and no more connections will be accepted.
2935 If this option is set then the timeouts used in a SMTP session
2936 should be lowered from their default values to
2937 their minimum values as specified in RFC 2821 and listed in
2941 .sh 2 "Measures against Denial of Service Attacks"
2944 has some built-in measures against simple denial of service (DoS) attacks.
2945 The SMTP server by default slows down if too many bad commands are
2946 issued or if some commands are repeated too often within a session.
2947 Details can be found in the source file
2948 .b sendmail/srvrsmtp.c
2949 by looking for the macro definitions of
2951 .b MAXNOOPCOMMANDS ,
2952 .b MAXHELOCOMMANDS ,
2953 .b MAXVRFYCOMMANDS ,
2955 .b MAXETRNCOMMANDS .
2956 If an SMTP command is issued more often than the corresponding
2958 value, then the response is delayed exponentially,
2959 starting with a sleep time of one second,
2960 up to a maximum of four minutes (as defined by
2963 .b MaxDaemonChildren
2964 is set to a value greater than zero,
2965 then this could make a DoS attack even worse since it
2966 keeps a connection open longer than necessary.
2967 Therefore a connection is terminated with a 421 SMTP reply code
2968 if the number of commands exceeds the limit by a factor of two and
2970 is set to a value greater than zero (the default is 25).
2971 .sh 2 "Delivery Mode"
2973 There are a number of delivery modes that
2980 configuration option.
2982 specify how quickly mail will be delivered.
2986 i deliver interactively (synchronously)
2987 b deliver in background (asynchronously)
2988 q queue only (don't deliver)
2989 d defer delivery attempts (don't deliver)
2991 There are tradeoffs.
2994 gives the sender the quickest feedback,
2995 but may slow down some mailers and
2996 is hardly ever necessary.
2999 delivers promptly but
3000 can cause large numbers of processes
3001 if you have a mailer that takes a long time to deliver a message.
3004 minimizes the load on your machine,
3005 but means that delivery may be delayed for up to the queue interval.
3008 is identical to mode
3010 except that it also prevents lookups in maps including the
3012 flag from working during the initial queue phase;
3013 it is intended for ``dial on demand'' sites where DNS lookups
3014 might cost real money.
3015 Some simple error messages
3016 (e.g., host unknown during the SMTP protocol)
3017 will be delayed using this mode.
3020 is the usual default.
3029 (deliver in background)
3031 will not expand aliases and follow .forward files
3032 upon initial receipt of the mail.
3033 This speeds up the response to RCPT commands.
3036 should not be used by the SMTP server.
3039 The level of logging can be set for
3041 The default using a standard configuration table is level 9.
3042 The levels are as follows:
3047 Serious system failures and potential security problems.
3049 Lost communications (network problems) and protocol failures.
3051 Other serious failures, malformed addresses, transient forward/include
3052 errors, connection timeouts.
3054 Minor failures, out of date alias databases, connection rejections
3055 via check_ rulesets.
3057 Message collection statistics.
3059 Creation of error messages,
3060 VRFY and EXPN commands.
3062 Delivery failures (host or user unknown, etc.).
3064 Successful deliveries and alias database rebuilds.
3066 Messages being deferred
3067 (due to a host being down, etc.).
3069 Database expansion (alias, forward, and userdb lookups)
3070 and authentication information.
3072 NIS errors and end of job processing.
3074 Logs all SMTP connections.
3076 Log bad user shells, files with improper permissions, and other
3077 questionable situations.
3079 Logs refused connections.
3081 Log all incoming and outgoing SMTP commands.
3083 Logs attempts to run locked queue files.
3084 These are not errors,
3085 but can be useful to note if your queue appears to be clogged.
3087 Lost locks (only if using lockf instead of flock).
3090 values above 64 are reserved for extremely verbose debugging output.
3091 No normal site would ever set these.
3094 The modes used for files depend on what functionality you want
3095 and the level of security you require.
3098 does careful checking of the modes
3099 of files and directories
3100 to avoid accidental compromise;
3101 if you want to make it possible to have group-writable support files
3102 you may need to use the
3103 .b DontBlameSendmail
3104 option to turn off some of these checks.
3105 .sh 3 "To suid or not to suid?"
3108 is no longer installed
3109 set-user-ID to root.
3111 explains how to configure and install
3113 without set-user-ID to root but set-group-ID
3114 which is the default configuration starting with 8.12.
3116 The daemon usually runs as root, unless other measures are taken.
3122 it checks to see if the userid is zero (root);
3124 it resets the userid and groupid to a default
3127 equate in the mailer line;
3128 if that is not set, the
3131 This can be overridden
3135 for mailers that are trusted
3136 and must be called as root.
3138 this will cause mail processing
3143 rather than to the user sending the mail.
3145 A middle ground is to set the
3150 to become the indicated user as soon as it has done the startup
3151 that requires root privileges
3152 (primarily, opening the
3159 .i /var/spool/mqueue )
3160 should be owned by that user,
3161 and all files and databases
3167 and external databases)
3168 must be readable by that user.
3169 Also, since sendmail will not be able to change its uid,
3170 delivery to programs or files will be marked as unsafe,
3171 e.g., undeliverable,
3175 and :include: files.
3176 Administrators can override this by setting the
3177 .b DontBlameSendmail
3178 option to the setting
3179 .b NonRootSafeAddr .
3181 is probably best suited for firewall configurations
3182 that don't have regular user logins.
3183 If the option is used on a system which performs local delivery,
3184 then the local delivery agent must have the proper permissions
3185 (i.e., usually set-user-ID root)
3186 since it will be invoked by the
3189 .sh 3 "Turning off security checks"
3192 is very particular about the modes of files that it reads or writes.
3193 For example, by default it will refuse to read most files
3194 that are group writable
3195 on the grounds that they might have been tampered with
3196 by someone other than the owner;
3197 it will even refuse to read files in group writable directories.
3198 Also, sendmail will refuse to create a new aliases database in an
3199 unsafe directory. You can get around this by manually creating the
3200 database file as a trusted user ahead of time and then rebuilding the
3201 aliases database with
3206 sure that your configuration is safe and you want
3208 to avoid these security checks,
3209 you can turn off certain checks using the
3210 .b DontBlameSendmail
3212 This option takes one or more names that disable checks.
3213 In the descriptions that follow,
3214 .q "unsafe directory"
3215 means a directory that is writable by anyone other than the owner.
3219 No special handling.
3223 system call is restricted to root.
3224 Since some versions of UNIX permit regular users
3225 to give away their files to other users on some filesystems,
3227 often cannot assume that a given file was created by the owner,
3228 particularly when it is in a writable directory.
3229 You can set this flag if you know that file giveaway is restricted
3231 .ip ClassFileInUnsafeDirPath
3232 When reading class files (using the
3234 line in the configuration file),
3235 allow files that are in unsafe directories.
3236 .ip DontWarnForwardFileInUnsafeDirPath
3238 unsafe directory path warnings
3239 for non-existent forward files.
3240 .ip ErrorHeaderInUnsafeDirPath
3241 Allow the file named in the
3243 option to be in an unsafe directory.
3244 .ip FileDeliveryToHardLink
3245 Allow delivery to files that are hard links.
3246 .ip FileDeliveryToSymLink
3247 Allow delivery to files that are symbolic links.
3248 .ip ForwardFileInGroupWritableDirPath
3251 files in group writable directories.
3252 .ip ForwardFileInUnsafeDirPath
3255 files in unsafe directories.
3256 .ip ForwardFileInUnsafeDirPathSafe
3259 file that is in an unsafe directory to include references
3260 to program and files.
3261 .ip GroupReadableKeyFile
3262 Accept a group-readable key file for STARTTLS.
3263 .ip GroupReadableSASLDBFile
3264 Accept a group-readable Cyrus SASL password file.
3265 .ip GroupWritableAliasFile
3266 Allow group-writable alias files.
3267 .ip GroupWritableDirPathSafe
3268 Change the definition of
3269 .q "unsafe directory"
3270 to consider group-writable directories to be safe.
3271 World-writable directories are always unsafe.
3272 .ip GroupWritableForwardFile
3273 Allow group writable
3276 .ip GroupWritableForwardFileSafe
3277 Accept group-writable
3279 files as safe for program and file delivery.
3280 .ip GroupWritableIncludeFile
3284 .ip GroupWritableIncludeFileSafe
3285 Accept group-writable
3287 files as safe for program and file delivery.
3288 .ip GroupWritableSASLDBFile
3289 Accept a group-writable Cyrus SASL password file.
3290 .ip HelpFileInUnsafeDirPath
3291 Allow the file named in the
3293 option to be in an unsafe directory.
3294 .ip IncludeFileInGroupWritableDirPath
3297 files in group writable directories.
3298 .ip IncludeFileInUnsafeDirPath
3301 files in unsafe directories.
3302 .ip IncludeFileInUnsafeDirPathSafe
3305 file that is in an unsafe directory to include references
3306 to program and files.
3307 .ip InsufficientEntropy
3308 Try to use STARTTLS even if the PRNG for OpenSSL is not properly seeded
3309 despite the security problems.
3310 .ip LinkedAliasFileInWritableDir
3311 Allow an alias file that is a link in a writable directory.
3312 .ip LinkedClassFileInWritableDir
3313 Allow class files that are links in writable directories.
3314 .ip LinkedForwardFileInWritableDir
3317 files that are links in writable directories.
3318 .ip LinkedIncludeFileInWritableDir
3321 files that are links in writable directories.
3322 .ip LinkedMapInWritableDir
3323 Allow map files that are links in writable directories.
3324 This includes alias database files.
3325 .ip LinkedServiceSwitchFileInWritableDir
3326 Allow the service switch file to be a link
3327 even if the directory is writable.
3328 .ip MapInUnsafeDirPath
3335 in unsafe directories.
3336 This includes alias database files.
3338 Do not mark file and program deliveries as unsafe
3339 if sendmail is not running with root privileges.
3340 .ip RunProgramInUnsafeDirPath
3341 Run programs that are in writable directories without logging a warning.
3342 .ip RunWritableProgram
3343 Run programs that are group- or world-writable without logging a warning.
3345 Allow group or world writable directories
3346 if the sticky bit is set on the directory.
3347 Do not set this on systems which do not honor
3348 the sticky bit on directories.
3349 .ip WorldWritableAliasFile
3350 Accept world-writable alias files.
3351 .ip WorldWritableForwardfile
3352 Allow world writable
3355 .ip WorldWritableIncludefile
3359 .ip WriteMapToHardLink
3360 Allow writes to maps that are hard links.
3361 .ip WriteMapToSymLink
3362 Allow writes to maps that are symbolic links.
3363 .ip WriteStatsToHardLink
3364 Allow the status file to be a hard link.
3365 .ip WriteStatsToSymLink
3366 Allow the status file to be a symbolic link.
3367 .sh 2 "Connection Caching"
3369 When processing the queue,
3371 will try to keep the last few open connections open
3372 to avoid startup and shutdown costs.
3373 This only applies to IPC and LPC connections.
3375 When trying to open a connection
3376 the cache is first searched.
3377 If an open connection is found, it is probed to see if it is still active
3381 It is not an error if this fails;
3382 instead, the connection is closed and reopened.
3384 Two parameters control the connection cache.
3386 .b ConnectionCacheSize
3389 option defines the number of simultaneous open connections
3390 that will be permitted.
3391 If it is set to zero,
3392 connections will be closed as quickly as possible.
3394 This should be set as appropriate for your system size;
3395 it will limit the amount of system resources that
3397 will use during queue runs.
3398 Never set this higher than 4.
3401 .b ConnectionCacheTimeout
3404 option specifies the maximum time that any cached connection
3405 will be permitted to idle.
3406 When the idle time exceeds this value
3407 the connection is closed.
3408 This number should be small
3410 to prevent you from grabbing too many resources
3412 The default is five minutes.
3413 .sh 2 "Name Server Access"
3415 Control of host address lookups is set by the
3417 service entry in your service switch file.
3418 If you are on a system that has built-in service switch support
3419 (e.g., Ultrix, Solaris, or DEC OSF/1)
3420 then your system is probably configured properly already.
3423 will consult the file
3424 .b /etc/mail/service.switch ,
3425 which should be created.
3427 only uses two entries:
3431 although system routines may use other services
3434 service for user name lookups by
3437 However, some systems (such as SunOS 4.X)
3439 regardless of the setting of the service switch entry.
3440 In particular, the system routine
3441 .i gethostbyname (3)
3442 is used to look up host names,
3443 and many vendor versions try some combination of DNS, NIS,
3444 and file lookup in /etc/hosts
3445 without consulting a service switch.
3447 makes no attempt to work around this problem,
3448 and the DNS lookup will be done anyway.
3449 If you do not have a nameserver configured at all,
3450 such as at a UUCP-only site,
3453 .q "connection refused"
3454 message when it tries to connect to the name server.
3457 switch entry has the service
3459 listed somewhere in the list,
3461 will interpret this to mean a temporary failure
3462 and will queue the mail for later processing;
3463 otherwise, it ignores the name server data.
3465 The same technique is used to decide whether to do MX lookups.
3466 If you want MX support, you
3470 listed as a service in the
3478 option allows you to tweak name server options.
3479 The command line takes a series of flags as documented in
3484 Each can be preceded by an optional `+' or `\(mi'.
3485 For example, the line
3487 O ResolverOptions=+AAONLY \(miDNSRCH
3489 turns on the AAONLY (accept authoritative answers only)
3490 and turns off the DNSRCH (search the domain path) options.
3491 Most resolver libraries default DNSRCH, DEFNAMES, and RECURSE
3492 flags on and all others off.
3493 If NETINET6 is enabled, most libraries default to USE_INET6 as well.
3494 You can also include
3496 to specify that there is a wildcard MX record matching your domain;
3497 this turns off MX matching when canonifying names,
3498 which can lead to inappropriate canonifications.
3500 .q WorkAroundBrokenAAAA
3501 when faced with a broken nameserver that returns SERVFAIL
3502 (a temporary failure)
3503 on T_AAAA (IPv6) lookups
3504 during hostname canonification.
3505 Notice: it might be necessary to apply the same (or similar) options to
3509 Version level 1 configurations (see the section about
3510 ``Configuration Version Level'')
3511 turn DNSRCH and DEFNAMES off when doing delivery lookups,
3512 but leave them on everywhere else.
3515 ignores them when doing canonification lookups
3516 (that is, when using $[ ... $]),
3517 and always does the search.
3518 If you don't want to do automatic name extension,
3519 don't call $[ ... $].
3521 The search rules for $[ ... $] are somewhat different than usual.
3522 If the name being looked up
3523 has at least one dot, it always tries the unmodified name first.
3524 If that fails, it tries the reduced search path,
3525 and lastly tries the unmodified name
3526 (but only for names without a dot,
3527 since names with a dot have already been tried).
3528 This allows names such as
3530 to match the site in Czechoslovakia
3531 rather than the site in your local Computer Science department.
3532 It also prefers A and CNAME records over MX records \*-
3533 that is, if it finds an MX record it makes note of it,
3535 This way, if you have a wildcard MX record matching your domain,
3536 it will not assume that all names match.
3538 To completely turn off all name server access
3539 on systems without service switch support
3541 you will have to recompile with
3543 and remove \-lresolv from the list of libraries to be searched
3545 .sh 2 "Moving the Per-User Forward Files"
3547 Some sites mount each user's home directory
3548 from a local disk on their workstation,
3549 so that local access is fast.
3550 However, the result is that .forward file lookups
3551 from a central mail server are slow.
3553 mail can even be delivered on machines inappropriately
3554 because of a file server being down.
3555 The performance can be especially bad if you run the automounter.
3561 option allows you to set a path of forward files.
3562 For example, the config file line
3564 O ForwardPath=/var/forward/$u:$z/.forward.$w
3566 would first look for a file with the same name as the user's login
3568 if that is not found (or is inaccessible)
3572 in the user's home directory is searched.
3573 A truly perverse site could also search by sender
3574 by using $r, $s, or $f.
3576 If you create a directory such as /var/forward,
3577 it should be mode 1777
3578 (that is, the sticky bit should be set).
3579 Users should create the files mode 0644.
3580 Note that you must use the
3581 ForwardFileInUnsafeDirPath and
3582 ForwardFileInUnsafeDirPathSafe
3584 .b DontBlameSendmail
3585 option to allow forward files in a world writable directory.
3586 This might also be used as a denial of service attack
3587 (users could create forward files for other users);
3588 a better approach might be to create
3591 and create empty files for each user,
3594 If you do this, you don't have to set the DontBlameSendmail options
3598 On systems that have one of the system calls in the
3605 you can specify a minimum number of free blocks on the queue filesystem
3611 If there are fewer than the indicated number of blocks free
3612 on the filesystem on which the queue is mounted
3613 the SMTP server will reject mail
3616 This invites the SMTP client to try again later.
3618 Beware of setting this option too high;
3619 it can cause rejection of email
3620 when that mail would be processed without difficulty.
3621 .sh 2 "Maximum Message Size"
3623 To avoid overflowing your system with a large message,
3626 option can be set to set an absolute limit
3627 on the size of any one message.
3628 This will be advertised in the ESMTP dialogue
3629 and checked during message collection.
3630 .sh 2 "Privacy Flags"
3636 option allows you to set certain
3639 Actually, many of them don't give you any extra privacy,
3640 rather just insisting that client SMTP servers
3641 use the HELO command
3642 before using certain commands
3643 or adding extra headers to indicate possible spoof attempts.
3645 The option takes a series of flag names;
3646 the final privacy is the inclusive or of those flags.
3649 O PrivacyOptions=needmailhelo, noexpn
3651 insists that the HELO or EHLO command be used before a MAIL command is accepted
3652 and disables the EXPN command.
3654 The flags are detailed in section
3657 .sh 2 "Send to Me Too"
3659 Beginning with version 8.10,
3661 includes by default the (envelope) sender in any list expansions.
3664 sends to a list that contains
3666 as one of the members he will get a copy of the message.
3671 (in the configuration file or via the command line),
3672 this behavior is changed, i.e.,
3673 the (envelope) sender is excluded in list expansions.
3674 .sh 1 "THE WHOLE SCOOP ON THE CONFIGURATION FILE"
3676 This section describes the configuration file
3679 There is one point that should be made clear immediately:
3680 the syntax of the configuration file
3681 is designed to be reasonably easy to parse,
3682 since this is done every time
3685 rather than easy for a human to read or write.
3686 The configuration file should be generated via the method described in
3688 it should not be edited directly unless someone is familiar
3689 with the internals of the syntax described here and it is
3690 not possible to achieve the desired result via the default method.
3692 The configuration file is organized as a series of lines,
3693 each of which begins with a single character
3694 defining the semantics for the rest of the line.
3695 Lines beginning with a space or a tab
3696 are continuation lines
3697 (although the semantics are not well defined in many places).
3698 Blank lines and lines beginning with a sharp symbol
3701 .sh 2 "R and S \*- Rewriting Rules"
3703 The core of address parsing
3704 are the rewriting rules.
3705 These are an ordered production system.
3707 scans through the set of rewriting rules
3708 looking for a match on the left hand side
3711 When a rule matches,
3712 the address is replaced by the right hand side
3716 There are several sets of rewriting rules.
3717 Some of the rewriting sets are used internally
3718 and must have specific semantics.
3719 Other rewriting sets
3720 do not have specifically assigned semantics,
3721 and may be referenced by the mailer definitions
3722 or by other rewriting sets.
3724 The syntax of these two commands are:
3729 Sets the current ruleset being collected to
3731 If you begin a ruleset more than once
3732 it appends to the old definition.
3740 fields must be separated
3741 by at least one tab character;
3742 there may be embedded spaces
3746 is a pattern that is applied to the input.
3748 the input is rewritten to the
3754 Macro expansions of the form
3757 are performed when the configuration file is read.
3760 can be included using
3762 Expansions of the form
3765 are performed at run time using a somewhat less general algorithm.
3766 This is intended only for referencing internally defined macros
3769 that are changed at runtime.
3770 .sh 3 "The left hand side"
3772 The left hand side of rewriting rules contains a pattern.
3773 Normal words are simply matched directly.
3774 Metasyntax is introduced using a dollar sign.
3775 The metasymbols are:
3777 .ta \w'\fB$=\fP\fIx\fP 'u
3778 \fB$*\fP Match zero or more tokens
3779 \fB$+\fP Match one or more tokens
3780 \fB$\-\fP Match exactly one token
3781 \fB$=\fP\fIx\fP Match any phrase in class \fIx\fP
3782 \fB$~\fP\fIx\fP Match any word not in class \fIx\fP
3784 If any of these match,
3785 they are assigned to the symbol
3788 for replacement on the right hand side,
3791 is the index in the LHS.
3797 is applied to the input:
3801 the rule will match, and the values passed to the RHS will be:
3808 Additionally, the LHS can include
3810 to match zero tokens.
3816 on the RHS, and is normally only used when it stands alone
3817 in order to match the null input.
3818 .sh 3 "The right hand side"
3820 When the left hand side of a rewriting rule matches,
3821 the input is deleted and replaced by the right hand side.
3822 Tokens are copied directly from the RHS
3823 unless they begin with a dollar sign.
3826 .ta \w'$#mailer\0\0\0'u
3827 \fB$\fP\fIn\fP Substitute indefinite token \fIn\fP from LHS
3828 \fB$[\fP\fIname\fP\fB$]\fP Canonicalize \fIname\fP
3829 \fB$(\fP\fImap key\fP \fB$@\fP\fIarguments\fP \fB$:\fP\fIdefault\fP \fB$)\fP
3830 Generalized keyed mapping function
3831 \fB$>\fP\fIn\fP \*(lqCall\*(rq ruleset \fIn\fP
3832 \fB$#\fP\fImailer\fP Resolve to \fImailer\fP
3833 \fB$@\fP\fIhost\fP Specify \fIhost\fP
3834 \fB$:\fP\fIuser\fP Specify \fIuser\fP
3840 syntax substitutes the corresponding value from a
3848 It may be used anywhere.
3850 A host name enclosed between
3854 is looked up in the host database(s)
3855 and replaced by the canonical name\**.
3858 completely equivalent
3859 to $(host \fIhostname\fP$).
3862 default can be used.
3867 .q ftp.CS.Berkeley.EDU
3869 .q $[[128.32.130.2]$]
3871 .q vangogh.CS.Berkeley.EDU.
3873 recognizes its numeric IP address
3874 without calling the name server
3875 and replaces it with its canonical name.
3881 syntax is a more general form of lookup;
3882 it uses a named map instead of an implicit map.
3883 If no lookup is found, the indicated
3886 if no default is specified and no lookup matches,
3887 the value is left unchanged.
3890 are passed to the map for possible use.
3896 causes the remainder of the line to be substituted as usual
3897 and then passed as the argument to ruleset
3899 The final value of ruleset
3902 the substitution for this rule.
3905 syntax expands everything after the ruleset name
3906 to the end of the replacement string
3907 and then passes that as the initial input to the ruleset.
3908 Recursive calls are allowed.
3913 expands $1, passes that to ruleset 3, and then passes the result
3914 of ruleset 3 to ruleset 0.
3920 be used in ruleset zero,
3921 a subroutine of ruleset zero,
3922 or rulesets that return decisions (e.g., check_rcpt).
3923 It causes evaluation of the ruleset to terminate immediately,
3926 that the address has completely resolved.
3927 The complete syntax for ruleset 0 is:
3929 \fB$#\fP\fImailer\fP \fB$@\fP\fIhost\fP \fB$:\fP\fIuser\fP
3932 {mailer, host, user}
3933 3-tuple necessary to direct the mailer.
3934 Note: the third element (
3936 ) is often also called
3939 If the mailer is local
3940 the host part may be omitted\**.
3942 \**You may want to use it for special
3945 For example, in the address
3946 .q jgm+foo@CMU.EDU ;
3949 part is not part of the user name,
3950 and is passed to the local mailer for local use.
3954 must be a single word,
3962 is the built-in IPC mailer,
3965 may be a colon-separated list of hosts
3966 that are searched in order for the first working address
3967 (exactly like MX records).
3970 is later rewritten by the mailer-specific envelope rewriting set
3974 As a special case, if the mailer specified has the
3977 and the first character of the
3983 is stripped off, and a flag is set in the address descriptor
3984 that causes sendmail to not do ruleset 5 processing.
3986 Normally, a rule that matches is retried,
3988 the rule loops until it fails.
3989 A RHS may also be preceded by a
3993 to change this behavior.
3996 prefix causes the ruleset to return with the remainder of the RHS
4000 prefix causes the rule to terminate immediately,
4001 but the ruleset to continue;
4002 this can be used to avoid continued application of a rule.
4003 The prefix is stripped before continuing.
4009 prefixes may precede a
4018 passes that to ruleset seven,
4022 is necessary to avoid an infinite loop.
4024 Substitution occurs in the order described,
4026 parameters from the LHS are substituted,
4027 hostnames are canonicalized,
4036 .sh 3 "Semantics of rewriting rule sets"
4038 There are six rewriting sets
4039 that have specific semantics.
4040 Five of these are related as depicted by figure 1.
4046 -->| 0 |-->resolved address
4049 / ---->| 1 |-->| S |--
4050 +---+ / +---+ / +---+ +---+ \e +---+
4051 addr-->| 3 |-->| D |-- --->| 4 |-->msg
4052 +---+ +---+ \e +---+ +---+ / +---+
4068 box invis "addr"; arrow
4071 BoxD: box "D"; line; L1: Here
4073 C1: arrow; box "1"; arrow; box "S"; line; E1: Here
4074 move to C1 down 0.5; right
4075 C2: arrow; box "2"; arrow; box "R"; line; E2: Here
4076 ] with .w at L1 + (0.5, 0)
4077 move to C.e right 0.5
4078 L4: arrow; box "4"; arrow; box invis "msg"
4079 line from L1 to C.C1
4080 line from L1 to C.C2
4081 line from C.E1 to L4
4082 line from C.E2 to L4
4083 move to BoxD.n up 0.6; right
4084 Box0: arrow; box "0"
4085 arrow; box invis "resolved address" width 1.3
4086 line from 1/3 of the way between A1 and BoxD.w to Box0
4092 Figure 1 \*- Rewriting set semantics
4094 D \*- sender domain addition
4095 S \*- mailer-specific sender rewriting
4096 R \*- mailer-specific recipient rewriting
4102 should turn the address into
4103 .q "canonical form."
4104 This form should have the basic syntax:
4106 local-part@host-domain-spec
4111 before doing anything with any address.
4126 flag is set in the mailer definition
4127 corresponding to the
4132 is applied after ruleset three
4133 to addresses that are going to actually specify recipients.
4134 It must resolve to a
4135 .i "{mailer, host, address}"
4139 must be defined in the mailer definitions
4140 from the configuration file.
4146 for use in the argv expansion of the specified mailer.
4147 Notice: since the envelope sender address will be used if
4148 a delivery status notification must be send,
4149 i.e., is may specify a recipient,
4150 it is also run through ruleset zero.
4151 If ruleset zero returns a temporary error
4153 then delivery is deferred.
4154 This can be used to temporarily disable delivery,
4155 e.g., based on the time of the day or other varying parameters.
4156 It should not be used to quarantine e-mails.
4158 Rulesets one and two
4159 are applied to all sender and recipient addresses respectively.
4160 They are applied before any specification
4161 in the mailer definition.
4162 They must never resolve.
4164 Ruleset four is applied to all addresses
4166 It is typically used
4167 to translate internal to external form.
4170 ruleset 5 is applied to all local addresses
4171 (specifically, those that resolve to a mailer with the `F=5'
4173 that do not have aliases.
4174 This allows a last minute hook for local names.
4175 .sh 3 "Ruleset hooks"
4177 A few extra rulesets are defined as
4179 that can be defined to get special features.
4180 They are all named rulesets.
4183 forms all give accept/reject status;
4184 falling off the end or returning normally is an accept,
4187 is a reject or quarantine.
4188 Quarantining is chosen by specifying
4190 in the second part of the mailer triplet:
4192 $#error $@ quarantine $: Reason for quarantine
4194 Many of these can also resolve to the special mailer name
4196 this accepts the message as though it were successful
4197 but then discards it without delivery.
4199 this mailer cannot be chosen as a mailer in ruleset 0.
4202 rulesets have to deal with temporary failures, especially for map lookups,
4203 themselves, i.e., they should return a temporary error code
4204 or at least they should make a proper decision in those cases.
4209 ruleset is called after a connection is accepted by the daemon.
4210 It is not called when sendmail is started using the
4215 client.host.name $| client.host.address
4219 is a metacharacter separating the two parts.
4220 This ruleset can reject connections from various locations.
4221 Note that it only checks the connecting SMTP client IP address and hostname.
4222 It does not check for third party message relaying.
4225 ruleset discussed below usually does third party message relay checking.
4230 ruleset is passed the user name parameter of the
4233 It can accept or reject the address.
4238 ruleset is passed the user name parameter of the
4241 It can accept or reject the address.
4246 ruleset is called after the
4248 command, its parameter is the number of recipients.
4249 It can accept or reject the command.
4250 .sh 4 "check_compat"
4256 sender-address $| recipient-address
4260 is a metacharacter separating the addresses.
4261 It can accept or reject mail transfer between these two addresses
4268 rulesets are invoked during the SMTP mail receiption stage
4269 (i.e., in the SMTP server),
4271 is invoked during the mail delivery stage.
4278 number-of-headers $| size-of-headers
4282 is a metacharacter separating the numbers.
4283 These numbers can be used for size comparisons with the
4286 The ruleset is triggered after
4287 all of the headers have been read.
4288 It can be used to correlate information gathered
4289 from those headers using the
4292 One possible use is to check for a missing header.
4297 HMessage-Id: $>CheckMessageId
4300 # Record the presence of the header
4301 R$* $: $(storage {MessageIdCheck} $@ OK $) $1
4303 R$* $#error $: 553 Header Error
4307 R$* $: < $&{MessageIdCheck} >
4308 # Clear the macro for the next message
4309 R$* $: $(storage {MessageIdCheck} $) $1
4310 # Has a Message-Id: header
4312 # Allow missing Message-Id: from local mail
4313 R$* $: < $&{client_name} >
4316 # Otherwise, reject the mail
4317 R$* $#error $: 553 Header Error
4319 Keep in mind the Message-Id: header is not a required header and
4320 is not a guaranteed spam indicator.
4321 This ruleset is an example and
4322 should probably not be used in production.
4327 ruleset is called after the end of a message,
4328 its parameter is the message size.
4329 It can accept or reject the message.
4334 ruleset is passed the parameter of the
4337 It can accept or reject the command.
4342 ruleset is passed the user name parameter of the
4345 It can accept or reject the address.
4350 ruleset is passed the user name parameter of the
4353 It can accept or reject the command.
4358 ruleset is passed the AUTH= parameter of the
4361 It is used to determine whether this value should be
4362 trusted. In order to make this decision, the ruleset
4363 may make use of the various
4366 If the ruleset does resolve to the
4368 mailer the AUTH= parameter is not trusted and hence
4369 not passed on to the next relay.
4374 ruleset is called when sendmail acts as server, after a STARTTLS command
4375 has been issued, and from
4377 The parameter is the value of
4379 and STARTTLS or MAIL, respectively.
4380 If the ruleset does resolve to the
4382 mailer, the appropriate error code is returned to the client.
4387 ruleset is called when sendmail acts as client after a STARTTLS command
4388 (should) have been issued.
4389 The parameter is the value of
4391 If the ruleset does resolve to the
4393 mailer, the connection is aborted
4394 (treated as non-deliverable with a permanent or temporary error).
4399 ruleset is called each time before a RCPT TO command is sent.
4400 The parameter is the current recipient.
4401 If the ruleset does resolve to the
4403 mailer, the RCPT TO command is suppressed
4404 (treated as non-deliverable with a permanent or temporary error).
4405 This ruleset allows to require encryption or verification of
4406 the recipient's MTA even if the mail is somehow redirected
4408 For example, sending mail to
4410 may get redirected to a host named
4412 and hence the tls_server ruleset won't apply.
4413 By introducing per recipient restrictions such attacks
4414 (e.g., via DNS spoofing) can be made impossible.
4417 how this ruleset can be used.
4418 .sh 4 "srv_features"
4422 ruleset is called with the connecting client's host name
4423 when a client connects to sendmail.
4424 This ruleset should return
4426 followed by a list of options (single characters
4427 delimited by white space).
4428 If the return value starts with anything else it is silently ignored.
4429 Generally upper case characters turn off a feature
4430 while lower case characters turn it on.
4431 Option `S' causes the server not to offer STARTTLS,
4432 which is useful to interact with MTAs/MUAs that have broken
4433 STARTTLS implementations by simply not offering it.
4434 `V' turns off the request for a client certificate during the TLS handshake.
4435 Options `A' and `P' suppress SMTP AUTH and PIPELINING, respectively.
4436 `c' is the equivalent to AuthOptions=p, i.e.,
4437 it doesn't permit mechanisms susceptible to simple
4438 passive attack (e.g., PLAIN, LOGIN), unless a security layer is active.
4439 Option `l' requires SMTP AUTH for a connection.
4440 Options 'B', 'D', 'E', and 'X' suppress SMTP VERB, DSN, ETRN, and EXPN,
4445 a Offer AUTH (default)
4447 b Offer VERB (default)
4448 C Do not require security layer for
4449 plaintext AUTH (default)
4450 c Require security layer for plaintext AUTH
4452 d Offer DSN (default)
4454 e Offer ETRN (default)
4455 L Do not require AUTH (default)
4457 P Do not offer PIPELINING
4458 p Offer PIPELINING (default)
4459 S Do not offer STARTTLS
4460 s Offer STARTTLS (default)
4461 V Do not request a client certificate
4462 v Request a client certificate (default)
4464 x Offer EXPN (default)
4466 Note: the entries marked as ``(default)'' may require that some
4467 configuration has been made, e.g., SMTP AUTH is only available if
4468 properly configured.
4469 Moreover, many options can be changed on a global basis via other
4470 settings as explained in this document, e.g., via DaemonPortOptions.
4472 The ruleset may return `$#temp' to indicate that there is a temporary
4473 problem determining the correct features, e.g., if a map is unavailable.
4474 In that case, the SMTP server issues a temporary failure and does not
4480 ruleset is called when sendmail connects to another MTA.
4481 If the ruleset does resolve to the
4483 mailer, sendmail does not try STARTTLS even if it is offered.
4484 This is useful to interact with MTAs that have broken
4485 STARTTLS implementations by simply not using it.
4490 ruleset is called when sendmail tries to authenticate to another MTA.
4493 followed by a list of tokens that are used for SMTP AUTH.
4494 If the return value starts with anything else it is silently ignored.
4495 Each token is a tagged string of the form:
4497 (including the quotes), where
4500 T Tag which describes the item
4501 D Delimiter: ':' simple text follows
4502 '=' string is base64 encoded
4503 string Value of the item
4505 Valid values for the tag are:
4508 U user (authorization) id
4512 M list of mechanisms delimited by spaces
4514 If this ruleset is defined, the option
4516 is ignored (even if the ruleset does not return a ``useful'' result).
4521 ruleset is used to map a recipient address to a queue group name.
4522 The input for the ruleset is a recipient address as specified by the
4525 The ruleset should return
4527 followed by the name of a queue group.
4528 If the return value starts with anything else it is silently ignored.
4529 See the section about ``Queue Groups and Queue Directories''
4530 for further information.
4535 ruleset is used to specify the amount of time to pause before sending the
4536 initial SMTP 220 greeting.
4537 If any traffic is received during that pause, an SMTP 554 rejection
4538 response is given instead of the 220 greeting and all SMTP commands are
4539 rejected during that connection.
4540 This helps protect sites from open proxies and SMTP slammers.
4541 The ruleset should return
4543 followed by the number of milliseconds (thousandths of a second) to
4545 If the return value starts with anything else or is not a number,
4546 it is silently ignored.
4547 Note: this ruleset is not invoked (and hence the feature is disabled)
4548 when the smtps (SMTP over SSL) is used, i.e.,
4551 modifier is set for the daemon via
4552 .b DaemonPortOptions ,
4553 because in this case the SSL handshake is performed before
4554 the greeting is sent.
4557 Some special processing occurs
4558 if the ruleset zero resolves to an IPC mailer
4559 (that is, a mailer that has
4561 listed as the Path in the
4564 The host name passed after
4566 has MX expansion performed if not delivering via a named socket;
4567 this looks the name up in DNS to find alternate delivery sites.
4569 The host name can also be provided as a dotted quad
4570 or an IPv6 address in square brackets;
4577 [IPv6:2002:c0a8:51d2::23f4]
4579 This causes direct conversion of the numeric value
4580 to an IP host address.
4582 The host name passed in after the
4584 may also be a colon-separated list of hosts.
4585 Each is separately MX expanded and the results are concatenated
4586 to make (essentially) one long MX list.
4587 The intent here is to create
4589 MX records that are not published in DNS
4590 for private internal networks.
4592 As a final special case, the host name can be passed in
4596 [ucbvax.berkeley.edu]
4598 This form avoids the MX mapping.
4601 This is intended only for situations where you have a network firewall
4602 or other host that will do special processing for all your mail,
4603 so that your MX record points to a gateway machine;
4604 this machine could then do direct delivery to machines
4605 within your local domain.
4606 Use of this feature directly violates RFC 1123 section 5.3.5:
4607 it should not be used lightly.
4609 .sh 2 "D \*- Define Macro"
4611 Macros are named with a single character
4612 or with a word in {braces}.
4613 The names ``x'' and ``{x}'' denote the same macro
4614 for every single character ``x''.
4615 Single character names may be selected from the entire ASCII set,
4616 but user-defined macros
4617 should be selected from the set of upper case letters only.
4620 are used internally.
4621 Long names beginning with a lower case letter or a punctuation character
4622 are reserved for use by sendmail,
4623 so user-defined long macro names should begin with an upper case letter.
4625 The syntax for macro definitions is:
4632 is the name of the macro
4633 (which may be a single character
4634 or a word in braces)
4637 is the value it should have.
4638 There should be no spaces given
4639 that do not actually belong in the macro value.
4641 Macros are interpolated
4647 is the name of the macro to be interpolated.
4648 This interpolation is done when the configuration file is read,
4652 The special construct
4657 lines to get deferred interpolation.
4659 Conditionals can be specified using the syntax:
4661 $?x text1 $| text2 $.
4667 is set and non-null,
4675 clause may be omitted.
4677 The following macros are defined and/or used internally by
4679 for interpolation into argv's for mailers
4680 or for other contexts.
4681 The ones marked \(dg are information passed into sendmail\**,
4683 \**As of version 8.6,
4684 all of these macros have reasonable defaults.
4685 Previous versions required that they be defined.
4687 the ones marked \(dd are information passed both in and out of sendmail,
4688 and the unmarked macros are passed out of sendmail
4689 but are not otherwise used internally.
4693 The origination date in RFC 822 format.
4694 This is extracted from the Date: line.
4696 The current date in RFC 822 format.
4699 This is a count of the number of Received: lines
4700 plus the value of the
4704 The current date in UNIX (ctime) format.
4706 (Obsolete; use SmtpGreetingMessage option instead.)
4707 The SMTP entry message.
4708 This is printed out when SMTP starts up.
4709 The first word must be the
4711 macro as specified by RFC 821.
4713 .q "$j Sendmail $v ready at $b" .
4714 Commonly redefined to include the configuration version number, e.g.,
4715 .q "$j Sendmail $v/$Z ready at $b"
4717 The envelope sender (from) address.
4719 The sender address relative to the recipient.
4727 .q foo@host.domain ,
4728 or whatever is appropriate for the receiving mailer.
4731 This is set in ruleset 0 from the $@ field of a parsed address.
4737 The \*(lqofficial\*(rq domain name for this site.
4738 This is fully qualified if the full qualification can be found.
4741 be redefined to be the fully qualified domain name
4742 if your system is not configured so that information can find
4745 The UUCP node name (from the uname system call).
4747 (Obsolete; use UnixFromLine option instead.)
4748 The format of the UNIX from line.
4749 Unless you have changed the UNIX mailbox format,
4750 you should not change the default,
4754 The domain part of the \fIgethostname\fP return value.
4755 Under normal circumstances,
4760 The name of the daemon (for error messages).
4764 (Obsolete: use OperatorChars option instead.)
4765 The set of \*(lqoperators\*(rq in addresses.
4766 A list of characters
4767 which will be considered tokens
4768 and which will separate tokens
4774 macro, then the input
4776 would be scanned as three tokens:
4783 which is the minimum set necessary to do RFC 822 parsing;
4784 a richer set of operators is
4786 which adds support for UUCP, the %-hack, and X.400 addresses.
4788 Sendmail's process id.
4790 Default format of sender address.
4793 macro specifies how an address should appear in a message
4794 when it is defaulted.
4797 It is commonly redefined to be
4798 .q "$?x$x <$g>$|$g$."
4801 corresponding to the following two formats:
4803 Eric Allman <eric@CS.Berkeley.EDU>
4804 eric@CS.Berkeley.EDU (Eric Allman)
4807 properly quotes names that have special characters
4808 if the first form is used.
4810 Protocol used to receive the message.
4813 command line flag or by the SMTP server code.
4818 command line flag or by the SMTP server code
4819 (in which case it is set to the EHLO/HELO parameter).
4821 A numeric representation of the current time in the format YYYYMMDDHHmm
4822 (4 digit year 1900-9999, 2 digit month 01-12, 2 digit day 01-31,
4823 2 digit hours 00-23, 2 digit minutes 00-59).
4827 The version number of the
4831 The hostname of this site.
4832 This is the root name of this host (but see below for caveats).
4834 The full name of the sender.
4836 The home directory of the recipient.
4838 The validated sender address.
4840 .b ${client_resolve} .
4842 The type of the address which is currently being rewritten.
4843 This macro contains up to three characters, the first
4844 is either `e' or `h' for envelope/header address,
4845 the second is a space,
4846 and the third is either `s' or `r' for sender/recipient address.
4848 The maximum keylength (in bits) of the symmetric encryption algorithm
4849 used for a TLS connection.
4850 This may be less than the effective keylength,
4853 for ``export controlled'' algorithms.
4855 The client's authentication credentials as determined by authentication
4856 (only set if successful).
4857 The format depends on the mechanism used, it might be just `user',
4858 or `user@realm', or something similar (SMTP AUTH only).
4860 The authorization identity, i.e. the AUTH= parameter of the
4862 command if supplied.
4864 The mechanism used for SMTP authentication
4865 (only set if successful).
4867 The keylength (in bits) of the symmetric encryption algorithm
4868 used for the security layer of a SASL mechanism.
4870 The message body type
4872 as determined from the envelope.
4874 The DN (distinguished name) of the CA (certificate authority)
4875 that signed the presented certificate (the cert issuer)
4878 The MD5 hash of the presented certificate (STARTTLS only).
4880 The DN of the presented certificate (called the cert subject)
4883 The cipher suite used for the connection, e.g., EDH-DSS-DES-CBC3-SHA,
4884 EDH-RSA-DES-CBC-SHA, DES-CBC-MD5, DES-CBC3-SHA
4887 The effective keylength (in bits) of the symmetric encryption algorithm
4888 used for a TLS connection.
4890 The IP address of the SMTP client.
4891 IPv6 addresses are tagged with "IPv6:" before the address.
4892 Defined in the SMTP server only.
4893 .ip ${client_connections}
4894 The number of open connections in the SMTP server for the client IP address.
4896 The flags specified by the
4898 .b ClientPortOptions
4899 where flags are separated from each other by spaces
4900 and upper case flags are doubled.
4903 will be represented as
4905 .b ${client_flags} ,
4906 which is required for testing the flags in rulesets.
4908 The host name of the SMTP client.
4909 This may be the client's bracketed IP address
4910 in the form [ nnn.nnn.nnn.nnn ] for IPv4
4911 and [ IPv6:nnnn:...:nnnn ] for IPv6
4913 IP address is not resolvable, or if it is resolvable
4914 but the IP address of the resolved hostname
4915 doesn't match the original IP address.
4916 Defined in the SMTP server only.
4918 .b ${client_resolve} .
4920 The port number of the SMTP client.
4921 Defined in the SMTP server only.
4923 The result of the PTR lookup for the client IP address.
4924 Note: this is the same as
4927 .b ${client_resolve}
4929 Defined in the SMTP server only.
4931 The number of incoming connections for the client IP address
4932 over the time interval specified by ConnectionRateWindowSize.
4933 .ip ${client_resolve}
4934 Holds the result of the resolve call for
4936 Possible values are:
4939 OK resolved successfully
4940 FAIL permanent lookup failure
4941 FORGED forward lookup doesn't match reverse lookup
4942 TEMP temporary lookup failure
4944 Defined in the SMTP server only.
4946 performs a hostname lookup on the IP address of the connecting client.
4947 Next the IP addresses of that hostname are looked up.
4948 If the client IP address does not appear in that list,
4949 then the hostname is maybe forged.
4950 This is reflected as the value FORGED for
4951 .b ${client_resolve}
4952 and it also shows up in
4954 as "(may be forged)".
4956 The CN (common name) of the CA that signed the presented certificate
4958 Note: if the CN cannot be extracted properly it will be replaced by
4959 one of these strings based on the encountered error:
4962 BadCertificateContainsNUL CN contains a NUL character
4963 BadCertificateTooLong CN is too long
4964 BadCertificateUnknown CN could not be extracted
4966 In the last case, some other (unspecific) error occurred.
4968 The CN (common name) of the presented certificate
4972 for possible replacements.
4974 Header value as quoted string
4975 (possibly truncated to
4977 This macro is only available in header check rulesets.
4979 The IP address the daemon is listening on for connections.
4980 .ip ${daemon_family}
4982 if the daemon is accepting network connections.
4983 Possible values include
4990 The flags for the daemon as specified by the
4992 .b DaemonPortOptions
4993 whereby the flags are separated from each other by spaces,
4994 and upper case flags are doubled.
4997 will be represented as
4999 .b ${daemon_flags} ,
5000 which is required for testing the flags in rulesets.
5002 Some information about a daemon as a text string.
5004 .q SMTP+queueing@00:30:00 .
5006 The name of the daemon from
5007 .b DaemonPortOptions
5009 If this suboption is not set,
5011 where # is the daemon number,
5014 The port the daemon is accepting connection on.
5016 .b DaemonPortOptions
5017 is set, this will most likely be
5020 The current delivery mode sendmail is using.
5021 It is initially set to the value of the
5025 The envelope id parameter (ENVID=) passed to sendmail as part of the envelope.
5027 The length of the header value which is stored in
5028 ${currHeader} (before possible truncation).
5029 If this value is greater than or equal to
5031 the header has been truncated.
5033 The name of the header field for which the current header
5034 check ruleset has been called.
5035 This is useful for a default header check ruleset to get
5036 the name of the header;
5037 the macro is only available in header check rulesets.
5039 The IP address of the interface of an incoming connection
5040 unless it is in the loopback net.
5041 IPv6 addresses are tagged with "IPv6:" before the address.
5043 The IP address of the interface of an outgoing connection
5044 unless it is in the loopback net.
5045 IPv6 addresses are tagged with "IPv6:" before the address.
5047 The IP family of the interface of an incoming connection
5048 unless it is in the loopback net.
5049 .ip ${if_family_out}
5050 The IP family of the interface of an outgoing connection
5051 unless it is in the loopback net.
5053 The hostname associated with the interface of an incoming connection.
5054 This macro can be used for
5055 SmtpGreetingMessage and HReceived for virtual hosting.
5058 O SmtpGreetingMessage=$?{if_name}${if_name}$|$j$. MTA
5061 The name of the interface of an outgoing connection.
5063 The current load average.
5065 The address part of the resolved triple of the address given for the
5068 Defined in the SMTP server only.
5070 The host from the resolved triple of the address given for the
5073 Defined in the SMTP server only.
5075 The mailer from the resolved triple of the address given for the
5078 Defined in the SMTP server only.
5080 The value of the Message-Id: header.
5082 The value of the SIZE= parameter,
5083 i.e., usually the size of the message (in an ESMTP dialogue),
5084 before the message has been collected, thereafter
5085 the message size as computed by
5087 (and can be used in check_compat).
5089 The number of bad recipients for a single message.
5091 The number of validated recipients for a single message.
5092 Note: since recipient validation happens after
5094 has been called, the value in this ruleset
5095 is one less than what might be expected.
5097 The number of delivery attempts.
5099 The current operation mode (from the
5103 The quarantine reason for the envelope,
5104 if it is quarantined.
5105 .ip ${queue_interval}
5106 The queue run interval given by the
5112 .b ${queue_interval}
5116 The address part of the resolved triple of the address given for the
5119 Defined in the SMTP server only after a RCPT command.
5121 The host from the resolved triple of the address given for the
5124 Defined in the SMTP server only after a RCPT command.
5126 The mailer from the resolved triple of the address given for the
5129 Defined in the SMTP server only after a RCPT command.
5131 The address of the server of the current outgoing SMTP connection.
5132 For LMTP delivery the macro is set to the name of the mailer.
5134 The name of the server of the current outgoing SMTP or LMTP connection.
5138 function, i.e., the number of seconds since 0 hours, 0 minutes,
5139 0 seconds, January 1, 1970, Coordinated Universal Time (UTC).
5141 The TLS/SSL version used for the connection, e.g., TLSv1, SSLv3, SSLv2;
5142 defined after STARTTLS has been used.
5144 The total number of incoming connections over the time interval specified
5145 by ConnectionRateWindowSize.
5147 The result of the verification of the presented cert;
5148 only defined after STARTTLS has been used (or attempted).
5149 Possible values are:
5152 OK verification succeeded.
5153 NO no cert presented.
5154 NOT no cert requested.
5155 FAIL cert presented but could not be verified,
5156 e.g., the signing CA is missing.
5157 NONE STARTTLS has not been performed.
5158 TEMP temporary error occurred.
5159 PROTOCOL some protocol error occurred
5160 at the ESMTP level (not TLS).
5161 SOFTWARE STARTTLS handshake failed,
5162 which is a fatal error for this session,
5163 the e-mail will be queued.
5166 There are three types of dates that can be used.
5171 macros are in RFC 822 format;
5173 is the time as extracted from the
5179 is the current date and time
5180 (used for postmarks).
5183 line is found in the incoming message,
5185 is set to the current time also.
5188 macro is equivalent to the
5199 are set to the identity of this host.
5201 tries to find the fully qualified name of the host
5203 it does this by calling
5205 to get the current hostname
5206 and then passing that to
5207 .i gethostbyname (3)
5208 which is supposed to return the canonical version of that host name.\**
5210 \**For example, on some systems
5214 which would be mapped to
5219 Assuming this is successful,
5221 is set to the fully qualified name
5224 is set to the domain part of the name
5225 (everything after the first dot).
5228 macro is set to the first word
5229 (everything before the first dot)
5230 if you have a level 5 or higher configuration file;
5231 otherwise, it is set to the same value as
5233 If the canonification is not successful,
5234 it is imperative that the config file set
5236 to the fully qualified domain name\**.
5238 \**Older versions of sendmail didn't pre-define
5240 at all, so up until 8.6,
5249 macro is the id of the sender
5250 as originally determined;
5251 when mailing to a specific host
5254 macro is set to the address of the sender
5256 relative to the recipient.
5259 .q bollard@matisse.CS.Berkeley.EDU
5261 .q vangogh.CS.Berkeley.EDU
5269 .q eric@vangogh.CS.Berkeley.EDU.
5273 macro is set to the full name of the sender.
5274 This can be determined in several ways.
5275 It can be passed as flag to
5277 It can be defined in the
5279 environment variable.
5280 The third choice is the value of the
5282 line in the header if it exists,
5283 and the fourth choice is the comment field
5287 If all of these fail,
5288 and if the message is being originated locally,
5289 the full name is looked up in the
5299 macros get set to the host, user, and home directory
5302 The first two are set from the
5306 part of the rewriting rules, respectively.
5312 macros are used to create unique strings
5318 macro is set to the queue id on this host;
5319 if put into the timestamp line
5320 it can be extremely useful for tracking messages.
5323 macro is set to be the version number of
5325 this is normally put in timestamps
5326 and has been proven extremely useful for debugging.
5332 i.e., the number of times this message has been processed.
5333 This can be determined
5336 flag on the command line
5337 or by counting the timestamps in the message.
5343 fields are set to the protocol used to communicate with
5345 and the sending hostname.
5346 They can be set together using the
5348 command line flag or separately using the
5356 is set to a validated sender host name.
5357 If the sender is running an RFC 1413 compliant IDENT server
5358 and the receiver has the IDENT protocol turned on,
5359 it will include the user name on that host.
5367 are set to the name, address, and port number of the SMTP client
5371 These can be used in the
5375 deferred evaluation form, of course!).
5376 .sh 2 "C and F \*- Define Classes"
5378 Classes of phrases may be defined
5379 to match on the left hand side of rewriting rules,
5382 is a sequence of characters that does not contain space characters.
5384 a class of all local names for this site
5386 so that attempts to send to oneself
5388 These can either be defined directly in the configuration file
5389 or read in from another file.
5390 Classes are named as a single letter or a word in {braces}.
5391 Class names beginning with lower case letters
5392 and special characters are reserved for system use.
5393 Classes defined in config files may be given names
5394 from the set of upper case letters for short names
5395 or beginning with an upper case letter for long names.
5410 .i c\|[mapkey]@mapclass:mapspec
5412 The first form defines the class
5414 to match any of the named words.
5422 the contents of class
5426 It is permissible to split them among multiple lines;
5427 for example, the two forms:
5438 read the elements of the class
5444 .i "map specification" .
5445 Each element should be listed on a separate line.
5446 To specify an optional file, use ``\-o'' between the class
5447 name and the file name, e.g.,
5449 Fc \-o /path/to/file
5451 If the file can't be used,
5453 will not complain but silently ignore it.
5454 The map form should be an optional map key, an at sign,
5455 and a map class followed by the specification for that map.
5458 F{VirtHosts}@ldap:\-k (&(objectClass=virtHosts)(host=*)) \-v host
5459 F{MyClass}foo@hash:/etc/mail/classes
5463 from an LDAP map lookup and
5465 from a hash database map lookup of the
5467 There is also a built-in schema that can be accessed by only specifying:
5472 This will tell sendmail to use the default schema:
5474 \-k (&(objectClass=sendmailMTAClass)
5475 (sendmailMTAClassName=\c
5477 (|(sendmailMTACluster=${sendmailMTACluster})
5478 (sendmailMTAHost=$j)))
5479 \-v sendmailMTAClassValue
5481 Note that the lookup is only done when sendmail is initially started.
5483 Elements of classes can be accessed in rules using
5489 (match entries not in class)
5490 only matches a single word;
5491 multi-word entries in the class are ignored in this context.
5493 Some classes have internal meaning to
5497 .\"A set of Content-Types that will not have the newline character
5498 .\"translated to CR-LF before encoding into base64 MIME.
5499 .\"The class can have major times
5504 .\".q application/octet-stream ).
5505 .\"The class is initialized with
5506 .\".q application/octet-stream ,
5512 contains the Content-Transfer-Encodings that can be 8\(->7 bit encoded.
5513 It is predefined to contain
5519 set to be the same as
5521 that is, the UUCP node name.
5523 set to the set of domains by which this host is known,
5527 can be set to the set of MIME body types
5528 that can never be eight to seven bit encoded.
5530 .q multipart/signed .
5535 are never encoded directly.
5536 Multipart messages are always handled recursively.
5537 The handling of message/* messages
5538 are controlled by class
5541 A set of Content-Types that will never be encoded as base64
5542 (if they have to be encoded, they will be encoded as quoted-printable).
5543 It can have primary types
5550 contains the set of subtypes of message that can be treated recursively.
5551 By default it contains only
5555 types cannot be 8\(->7 bit encoded.
5556 If a message containing eight bit data is sent to a seven bit host,
5557 and that message cannot be encoded into seven bits,
5558 it will be stripped to 7 bits.
5560 set to the set of trusted users by the
5563 If you want to read trusted users from a file, use
5567 set to be the set of all names
5568 this host is known by.
5569 This can be used to match local hostnames.
5570 .ip $={persistentMacros}
5571 set to the macros that should be saved across queue runs.
5572 Care should be taken when adding macro names to this class.
5575 can be compiled to allow a
5580 This lets you do simplistic parsing of text files.
5581 For example, to read all the user names in your system
5583 file into a class, use
5587 which reads every line up to the first colon.
5588 .sh 2 "M \*- Define Mailer"
5590 Programs and interfaces to mailers
5591 are defined in this line.
5602 is the name of the mailer
5603 (used internally only)
5606 pairs define attributes of the mailer.
5610 Path The pathname of the mailer
5611 Flags Special flags for this mailer
5612 Sender Rewriting set(s) for sender addresses
5613 Recipient Rewriting set(s) for recipient addresses
5614 recipients Maximum number of recipients per connection
5615 Argv An argument vector to pass to this mailer
5616 Eol The end-of-line string for this mailer
5617 Maxsize The maximum message length to this mailer
5618 maxmessages The maximum message deliveries per connection
5619 Linelimit The maximum line length in the message body
5620 Directory The working directory for the mailer
5621 Userid The default user and group id to run as
5622 Nice The nice(2) increment for the mailer
5623 Charset The default character set for 8-bit characters
5624 Type Type information for DSN diagnostics
5625 Wait The maximum time to wait for the mailer
5626 Queuegroup The default queue group for the mailer
5627 / The root directory for the mailer
5629 Only the first character of the field name is checked
5630 (it's case-sensitive).
5632 The following flags may be set in the mailer description.
5633 Any other flags may be used freely
5634 to conditionally assign headers to messages
5635 destined for particular mailers.
5636 Flags marked with \(dg
5637 are not interpreted by the
5640 these are the conventionally used to correlate to the flags portion
5644 Flags marked with \(dd
5645 apply to the mailers for the sender address
5646 rather than the usual recipient mailers.
5649 Run Extended SMTP (ESMTP) protocol (defined in RFCs 1869, 1652, and 1870).
5650 This flag defaults on if the SMTP greeting message includes the word
5653 Look up the user (address) part of the resolved mailer triple,
5654 in the alias database.
5655 Normally this is only set for local mailers.
5657 Force a blank line on the end of a message.
5658 This is intended to work around some stupid versions of
5660 that require a blank line, but do not provide it themselves.
5661 It would not normally be used on network mail.
5663 Strip leading backslashes (\e) off of the address;
5664 this is a subset of the functionality of the
5668 Do not include comments in addresses.
5669 This should only be used if you have to work around
5670 a remote mailer that gets confused by comments.
5671 This strips addresses of the form
5672 .q "Phrase <address>"
5674 .q "address (Comment)"
5680 from a mailer with this flag set,
5681 any addresses in the header that do not have an at sign
5684 after being rewritten by ruleset three
5687 clause from the sender envelope address
5689 This allows mail with headers of the form:
5692 To: userb@hostb, userc
5697 To: userb@hostb, userc@hosta
5700 However, it doesn't really work reliably.
5702 Do not include angle brackets around route-address syntax addresses.
5703 This is useful on mailers that are going to pass addresses to a shell
5704 that might interpret angle brackets as I/O redirection.
5705 However, it does not protect against other shell metacharacters.
5706 Therefore, passing addresses to a shell should not be considered secure.
5712 This mailer is expensive to connect to,
5713 so try to avoid connecting normally;
5714 any necessary connection will occur during a queue run.
5718 Escape lines beginning with
5720 in the message with a `>' sign.
5726 but only if this is a network forward operation
5728 the mailer will give an error
5729 if the executing user
5730 does not have special permissions).
5738 sends internally generated email (e.g., error messages)
5739 using the null return address
5740 as required by RFC 1123.
5741 However, some mailers don't accept a null return address.
5747 from obeying the standards;
5748 error messages will be sent as from the MAILER-DAEMON
5749 (actually, the value of the
5753 Upper case should be preserved in host names
5754 (the $@ portion of the mailer triplet resolved from ruleset 0)
5757 Do User Database rewriting on envelope sender address.
5759 This mailer will be speaking SMTP
5763 as such it can use special protocol features.
5764 This flag should not be used except for debugging purposes
5769 Do User Database rewriting on recipients as well as senders.
5773 connects to a host via SMTP,
5774 it checks to make sure that this isn't accidently the same host name
5777 is misconfigured or if a long-haul network interface is set in loopback mode.
5778 This flag disables the loopback check.
5779 It should only be used under very unusual circumstances.
5781 Currently unimplemented.
5782 Reserved for chunking.
5784 This mailer is local
5786 final delivery will be performed).
5788 Limit the line lengths as specified in RFC 821.
5789 This deprecated option should be replaced by the
5792 For historic reasons, the
5798 This mailer can send to multiple users
5805 part of the mailer definition,
5806 that field will be repeated as necessary
5807 for all qualifying users.
5808 Removing this flag can defeat duplicate supression on a remote site
5809 as each recipient is sent in a separate transaction.
5815 Do not insert a UNIX-style
5817 line on the front of the message.
5819 Always run as the owner of the recipient mailbox.
5822 runs as the sender for locally generated mail
5825 (actually, the user specified in the
5828 when delivering network mail.
5829 The normal behavior is required by most local mailers,
5830 which will not allow the envelope sender address
5831 to be set unless the mailer is running as daemon.
5832 This flag is ignored if the
5836 Use the route-addr style reverse-path in the SMTP
5839 rather than just the return address;
5840 although this is required in RFC 821 section 3.1,
5841 many hosts do not process reverse-paths properly.
5842 Reverse-paths are officially discouraged by RFC 1123.
5848 When an address that resolves to this mailer is verified
5849 (SMTP VRFY command),
5850 generate 250 responses instead of 252 responses.
5851 This will imply that the address is local.
5859 Open SMTP connections from a
5864 except on UNIX machines,
5865 so it is unclear that this adds anything.
5867 must be running as root to be able to use this flag.
5869 Strip quote characters (" and \e) off of the address
5870 before calling the mailer.
5872 Don't reset the userid
5873 before calling the mailer.
5874 This would be used in a secure environment
5878 This could be used to avoid forged addresses.
5881 field is also specified,
5882 this flag causes the effective user id to be set to that user.
5884 Upper case should be preserved in user names for this mailer. Standards
5885 require preservation of case in the local part of addresses, except for
5886 those address for which your system accepts responsibility.
5887 RFC 2142 provides a long list of addresses which should be case
5889 If you use this flag, you may be violating RFC 2142.
5890 Note that postmaster is always treated as a case insensitive address
5891 regardless of this flag.
5893 This mailer wants UUCP-style
5896 .q "remote from <host>"
5899 The user must have a valid account on this machine,
5903 If not, the mail is bounced.
5907 This is required to get
5911 Ignore long term host status information (see Section
5912 "Persistent Host Status Information").
5918 This mailer wants to use the hidden dot algorithm as specified in RFC 821;
5919 basically, any line beginning with a dot will have an extra dot prepended
5920 (to be stripped at the other end).
5921 This insures that lines in the message containing a dot
5922 will not terminate the message prematurely.
5924 Run Local Mail Transfer Protocol (LMTP)
5927 and the local mailer.
5928 This is a variant on SMTP
5930 that is specifically designed for delivery to a local mailbox.
5932 Apply DialDelay (if set) to this mailer.
5934 Don't look up MX records for hosts sent via SMTP/LMTP.
5939 Don't send null characters ('\\0') to this mailer.
5941 Don't use ESMTP even if offered; this is useful for broken
5942 systems that offer ESMTP but fail on EHLO (without recovering
5943 when HELO is tried next).
5945 Extend the list of characters converted to =XX notation
5946 when converting to Quoted-Printable
5947 to include those that don't map cleanly between ASCII and EBCDIC.
5948 Useful if you have IBM mainframes on site.
5950 If no aliases are found for this address,
5951 pass the address through ruleset 5 for possible alternate resolution.
5952 This is intended to forward the mail to an alternate delivery spot.
5954 Strip headers to seven bits.
5956 Strip all output to seven bits.
5957 This is the default if the
5960 Note that clearing this option is not
5961 sufficient to get full eight bit data passed through
5965 option is set, this is essentially always set,
5966 since the eighth bit was stripped on input.
5967 Note that this option will only impact messages
5968 that didn't have 8\(->7 bit MIME conversions performed.
5971 it is acceptable to send eight bit data to this mailer;
5972 the usual attempt to do 8\(->7 bit MIME conversions will be bypassed.
5977 7\(->8 bit MIME conversions.
5978 These conversions are limited to text/plain data.
5980 Check addresses to see if they begin
5982 if they do, convert them to the
5986 Check addresses to see if they begin with a `|';
5987 if they do, convert them to the
5991 Check addresses to see if they begin with a `/';
5992 if they do, convert them to the
5996 Look up addresses in the user database.
5998 Do not attempt delivery on initial receipt of a message
6000 unless the queued message is selected
6001 using one of the -qI/-qR/-qS queue run modifiers
6004 Disable an MH hack that drops an explicit
6006 if it is the same as what sendmail would generate.
6008 Configuration files prior to level 6
6009 assume the `A', `w', `5', `:', `|', `/', and `@' options
6013 The mailer with the special name
6015 can be used to generate a user error.
6016 The (optional) host field is an exit status to be returned,
6017 and the user field is a message to be printed.
6018 The exit status may be numeric or one of the values
6019 USAGE, NOUSER, NOHOST, UNAVAILABLE, SOFTWARE, TEMPFAIL, PROTOCOL, or CONFIG
6020 to return the corresponding EX_ exit code,
6021 or an enhanced error code as described in RFC 1893,
6023 Enhanced Mail System Status Codes.
6024 For example, the entry:
6026 $#error $@ NOHOST $: Host unknown in this domain
6028 on the RHS of a rule
6029 will cause the specified error to be generated
6032 exit status to be returned
6034 This mailer is only functional in rulesets 0, 5,
6035 or one of the check_* rulesets.
6036 The host field can also contain the special token
6038 which instructs sendmail to quarantine the current message.
6040 The mailer with the special name
6042 causes any mail sent to it to be discarded
6043 but otherwise treated as though it were successfully delivered.
6044 This mailer cannot be used in ruleset 0,
6045 only in the various address checking rulesets.
6050 be defined in every configuration file.
6051 This is used to deliver local mail,
6052 and is treated specially in several ways.
6053 Additionally, three other mailers named
6058 may be defined to tune the delivery of messages to programs,
6060 and :include: lists respectively.
6063 Mprog, P=/bin/sh, F=lsoDq9, T=DNS/RFC822/X-Unix, A=sh \-c $u
6064 M*file*, P=[FILE], F=lsDFMPEouq9, T=DNS/RFC822/X-Unix, A=FILE $u
6065 M*include*, P=/dev/null, F=su, A=INCLUDE $u
6068 Builtin pathnames are [FILE] and [IPC], the former is used for
6069 delivery to files, the latter for delivery via interprocess communication.
6070 For mailers that use [IPC] as pathname the argument vector (A=)
6071 must start with TCP or FILE for delivery via a TCP or a Unix domain socket.
6072 If TCP is used, the second argument must be the name of the host
6074 Optionally a third argument can be used to specify a port,
6075 the default is smtp (port 25).
6076 If FILE is used, the second argument must be the name of
6077 the Unix domain socket.
6079 If the argument vector does not contain $u then
6081 will speak SMTP (or LMTP if the mailer flag z is specified) to the mailer.
6083 If no Eol field is defined, then the default is "\\r\\n" for
6084 SMTP mailers and "\\n" of others.
6086 The Sender and Recipient rewriting sets
6087 may either be a simple ruleset id
6088 or may be two ids separated by a slash;
6089 if so, the first rewriting set is applied to envelope
6091 and the second is applied to headers.
6092 Setting any value to zero disables corresponding mailer-specific rewriting.
6095 is actually a colon-separated path of directories to try.
6096 For example, the definition
6098 first tries to execute in the recipient's home directory;
6099 if that is not available,
6100 it tries to execute in the root of the filesystem.
6101 This is intended to be used only on the
6104 since some shells (such as
6106 refuse to execute if they cannot read the current directory.
6107 Since the queue directory is not normally readable by unprivileged users
6109 scripts as recipients can fail.
6112 specifies the default user and group id to run as,
6118 mailer flag is also specified,
6119 this user and group will be set as the
6120 effective uid and gid for the process.
6121 This may be given as
6123 to set both the user and group id;
6124 either may be an integer or a symbolic name to be looked up
6130 If only a symbolic user name is specified,
6133 file for that user is used as the group id.
6136 is used when converting a message to MIME;
6137 this is the character set used in the
6138 Content-Type: header.
6139 If this is not set, the
6142 and if that is not set, the value
6146 this field applies to the sender's mailer,
6147 not the recipient's mailer.
6148 For example, if the envelope sender address
6149 lists an address on the local network
6150 and the recipient is on an external network,
6151 the character set will be set from the Charset= field
6152 for the local network mailer,
6153 not that of the external network mailer.
6156 sets the type information
6157 used in MIME error messages
6160 It is actually three values separated by slashes:
6161 the MTA-type (that is, the description of how hosts are named),
6162 the address type (the description of e-mail addresses),
6163 and the diagnostic type (the description of error diagnostic codes).
6164 Each of these must be a registered value
6168 .q dns/rfc822/smtp .
6170 The m= field specifies the maximum number of messages
6171 to attempt to deliver on a single SMTP or LMTP connection.
6172 The default is infinite.
6174 The r= field specifies the maximum number of recipients
6175 to attempt to deliver in a single envelope.
6178 The /= field specifies a new root directory for the mailer. The path is
6179 macro expanded and then passed to the
6181 system call. The root directory is changed before the Directory field is
6182 consulted or the uid is changed.
6184 The Wait= field specifies the maximum time to wait for the
6185 mailer to return after sending all data to it.
6186 This applies to mailers that have been forked by
6189 The Queuegroup= field specifies the default queue group in which
6190 received mail should be queued.
6191 This can be overridden by other means as explained in section
6192 ``Queue Groups and Queue Directories''.
6193 .sh 2 "H \*- Define Header"
6195 The format of the header lines that
6197 inserts into the message
6201 The syntax of this line is one of the following:
6228 Continuation lines in this spec
6229 are reflected directly into the outgoing message.
6232 is macro-expanded before insertion into the message.
6235 (surrounded by question marks)
6237 at least one of the specified flags
6238 must be stated in the mailer definition
6239 for this header to be automatically output.
6242 (surrounded by question marks)
6244 the header will be automatically output
6245 if the macro is set.
6246 The macro may be set using any of the normal methods,
6249 storage map in a ruleset.
6250 If one of these headers is in the input
6251 it is reflected to the output
6252 regardless of these flags or macros.
6256 is used to set a header, then it is useful to add that macro to class
6257 .i $={persistentMacros}
6258 which consists of the macros that should be saved across queue runs.
6260 Some headers have special semantics
6261 that will be described later.
6263 A secondary syntax allows validation of headers as they are being read.
6264 To enable validation, use:
6277 is called for the specified
6281 to reject or quarantine the message or
6283 to discard the message
6287 The ruleset receives the header field-body as argument,
6288 i.e., not the header field-name; see also
6289 ${hdr_name} and ${currHeader}.
6290 The header is treated as a structured field,
6292 text in parentheses is deleted before processing,
6293 unless the second form
6296 Note: only one ruleset can be associated with a header;
6298 will silently ignore multiple entries.
6300 For example, the configuration lines:
6302 HMessage-Id: $>CheckMessageId
6306 R$* $#error $: Illegal Message-Id header
6308 would refuse any message that had a Message-Id: header of any of the
6312 Message-Id: some text
6313 Message-Id: <legal text@domain> extra crud
6315 A default ruleset that is called for headers which don't have a
6316 specific ruleset defined for them can be specified by:
6330 .sh 2 "O \*- Set Option"
6332 There are a number of global options that
6333 can be set from a configuration file.
6334 Options are represented by full words;
6335 some are also representable as single characters for back compatibility.
6336 The syntax of this line is:
6349 be a space between the letter `O' and the name of the option.
6350 An older version is:
6357 is a single character.
6358 Depending on the option,
6360 may be a string, an integer,
6368 the default is TRUE),
6372 All filenames used in options should be absolute paths,
6373 i.e., starting with '/'.
6374 Relative filenames most likely cause surprises during operation
6375 (unless otherwise noted).
6377 The options supported (with the old, one character names in brackets) are:
6379 .ip "AliasFile=\fIspec, spec, ...\fP"
6381 Specify possible alias file(s).
6384 should be in the format
6392 is optional and defaults to ``implicit''.
6407 value is used as follows:
6409 \-k (&(objectClass=sendmailMTAAliasObject)
6410 (sendmailMTAAliasName=aliases)
6411 (|(sendmailMTACluster=${sendmailMTACluster})
6412 (sendmailMTAHost=$j))
6413 (sendmailMTAKey=%0))
6414 \-v sendmailMTAAliasValue
6418 is compiled, valid classes are
6420 (search through a compiled-in list of alias file types,
6421 for back compatibility),
6435 (internal symbol table \*- not normally used
6436 unless you have no other database lookup),
6438 (use a sequence of maps
6439 previously declared),
6453 searches them in order.
6454 .ip AliasWait=\fItimeout\fP
6459 (units default to minutes)
6462 entry to exist in the alias database
6464 If it does not appear in the
6466 interval issue a warning.
6469 If set, allow HELO SMTP commands that don't include a host name.
6470 Setting this violates RFC 1123 section 5.2.5,
6471 but is necessary to interoperate with several SMTP clients.
6472 If there is a value, it is still checked for legitimacy.
6473 .ip AuthMaxBits=\fIN\fP
6475 Limit the maximum encryption strength for the security layer in
6476 SMTP AUTH (SASL). Default is essentially unlimited.
6477 This allows to turn off additional encryption in SASL if
6478 STARTTLS is already encrypting the communication, because the
6479 existing encryption strength is taken into account when choosing
6480 an algorithm for the security layer.
6481 For example, if STARTTLS is used and the symmetric cipher is 3DES,
6482 then the the keylength (in bits) is 168.
6485 to 168 will disable any encryption in SASL.
6488 List of authentication mechanisms for AUTH (separated by spaces).
6489 The advertised list of authentication mechanisms will be the
6490 intersection of this list and the list of available mechanisms as
6491 determined by the Cyrus SASL library.
6492 If STARTTLS is active, EXTERNAL will be added to this list.
6493 In that case, the value of {cert_subject} is used as authentication id.
6496 List of options for SMTP AUTH consisting of single characters
6497 with intervening white space or commas.
6500 A Use the AUTH= parameter for the MAIL FROM
6501 command only when authentication succeeded.
6502 This can be used as a workaround for broken
6503 MTAs that do not implement RFC 2554 correctly.
6504 a protection from active (non-dictionary) attacks
6505 during authentication exchange.
6506 c require mechanisms which pass client credentials,
6507 and allow mechanisms which can pass credentials
6509 d don't permit mechanisms susceptible to passive
6511 f require forward secrecy between sessions
6512 (breaking one won't help break next).
6513 m require mechanisms which provide mutual authentication
6514 (only available if using Cyrus SASL v2 or later).
6515 p don't permit mechanisms susceptible to simple
6516 passive attack (e.g., PLAIN, LOGIN), unless a
6517 security layer is active.
6518 y don't permit mechanisms that allow anonymous login.
6520 The first option applies to sendmail as a client, the others to a server.
6525 would disallow ANONYMOUS as AUTH mechanism and would
6526 allow PLAIN and LOGIN only if a security layer (e.g.,
6527 provided by STARTTLS) is already active.
6528 The options 'a', 'c', 'd', 'f', 'p', and 'y' refer to properties of the
6529 selected SASL mechanisms.
6530 Explanations of these properties can be found in the Cyrus SASL documentation.
6533 The authentication realm that is passed to the Cyrus SASL library.
6534 If no realm is specified,
6537 .ip BadRcptThrottle=\fIN\fP
6539 If set and the specified number of recipients in a single SMTP
6540 transaction have been rejected, sleep for one second after each subsequent
6541 RCPT command in that transaction.
6542 .ip BlankSub=\fIc\fP
6544 Set the blank substitution character to
6546 Unquoted spaces in addresses are replaced by this character.
6547 Defaults to space (i.e., no change is made).
6550 Path to directory with certificates of CAs.
6551 This directory directory must contain the hashes of each CA certificate
6552 as filenames (or as links to them).
6555 File containing one or more CA certificates;
6556 see section about STARTTLS for more information.
6559 Validate the RHS of aliases when rebuilding the alias database.
6560 .ip CheckpointInterval=\fIN\fP
6562 Checkpoints the queue every
6566 If your system crashes during delivery to a large list,
6567 this prevents retransmission to any but the last
6570 .ip ClassFactor=\fIfact\fP
6574 is multiplied by the message class
6575 (determined by the Precedence: field in the user header
6578 lines in the configuration file)
6579 and subtracted from the priority.
6580 Thus, messages with a higher Priority: will be favored.
6584 File containing the certificate of the client, i.e., this certificate
6587 acts as client (for STARTTLS).
6590 File containing the private key belonging to the client certificate
6594 .ip ClientPortOptions=\fIoptions\fP
6596 Set client SMTP options.
6599 pairs separated by commas.
6603 Port Name/number of source port for connection (defaults to any free port)
6604 Addr Address mask (defaults INADDR_ANY)
6605 Family Address family (defaults to INET)
6606 SndBufSize Size of TCP send buffer
6607 RcvBufSize Size of TCP receive buffer
6608 Modifier Options (flags) for the client
6612 mask may be a numeric address in IPv4 dot notation or IPv6 colon notation
6614 Note that if a network name is specified,
6615 only the first IP address returned for it will be used.
6616 This may cause indeterminate behavior for network names
6617 that resolve to multiple addresses.
6618 Therefore, use of an address is recommended.
6620 can be the following character:
6623 h use name of interface for HELO command
6624 A don't use AUTH when sending e-mail
6625 S don't use STARTTLS when sending e-mail
6627 If ``h'' is set, the name corresponding to the outgoing interface
6628 address (whether chosen via the Connection parameter or
6629 the default) is used for the HELO/EHLO command.
6630 However, the name must not start with a square bracket
6631 and it must contain at least one dot.
6632 This is a simple test whether the name is not
6633 an IP address (in square brackets) but a qualified hostname.
6634 Note that multiple ClientPortOptions settings are allowed
6635 in order to give settings for each protocol family
6636 (e.g., one for Family=inet and one for Family=inet6).
6637 A restriction placed on one family only affects
6638 outgoing connections on that particular family.
6641 If set, colons are acceptable in e-mail addresses
6644 If not set, colons indicate the beginning of a RFC 822 group construct
6646 .q "groupname: member1, member2, ... memberN;" ).
6647 Doubled colons are always acceptable
6650 and proper route-addr nesting is understood
6652 .q <@relay:user@host> ).
6653 Furthermore, this option defaults on if the configuration version level
6654 is less than 6 (for back compatibility).
6655 However, it must be off for full compatibility with RFC 822.
6656 .ip ConnectionCacheSize=\fIN\fP
6658 The maximum number of open connections that will be cached at a time.
6660 This delays closing the current connection until
6661 either this invocation of
6663 needs to connect to another host
6665 Setting it to zero defaults to the old behavior,
6666 that is, connections are closed immediately.
6667 Since this consumes file descriptors,
6668 the connection cache should be kept small:
6669 4 is probably a practical maximum.
6670 .ip ConnectionCacheTimeout=\fItimeout\fP
6672 The maximum amount of time a cached connection will be permitted to idle
6674 If this time is exceeded,
6675 the connection is immediately closed.
6676 This value should be small (on the order of ten minutes).
6679 uses a cached connection,
6680 it always sends a RSET command
6681 to check the connection;
6682 if this fails, it reopens the connection.
6683 This keeps your end from failing if the other end times out.
6684 The point of this option is to be a good network neighbor
6685 and avoid using up excessive resources
6687 The default is five minutes.
6688 .ip ConnectOnlyTo=\fIaddress\fP
6691 override the connection address (for testing purposes).
6692 .ip ConnectionRateThrottle=\fIN\fP
6694 If set to a positive value,
6697 incoming connections in a one second period per daemon.
6698 This is intended to flatten out peaks
6699 and allow the load average checking to cut in.
6700 Defaults to zero (no limits).
6701 .ip ConnectionRateWindowSize=\fIN\fP
6703 Define the length of the interval for which
6704 the number of incoming connections is maintained.
6705 The default is 60 seconds.
6706 .ip ControlSocketName=\fIname\fP
6708 Name of the control socket for daemon management.
6711 daemon can be controlled through this named socket.
6712 Available commands are:
6721 command returns the current number of daemon children,
6722 the maximum number of daemon children,
6723 the free disk space (in blocks) of the queue directory,
6724 and the load average of the machine expressed as an integer.
6725 If not set, no control socket will be available.
6726 Solaris and pre-4.4BSD kernel users should see the note in sendmail/README .
6727 .ip CRLFile=\fIname\fP
6729 Name of file that contains certificate
6730 revocation status, useful for X.509v3 authentication.
6731 CRL checking requires at least OpenSSL version 0.9.7.
6732 Note: if a CRLFile is specified but the file is unusable,
6733 STARTTLS is disabled.
6735 Possible values are:
6738 5 use precomputed 512 bit prime
6739 1 generate 1024 bit prime
6740 2 generate 2048 bit prime
6741 none do not use Diffie-Hellman
6742 NAME load prime from file
6744 This is only required if a ciphersuite containing DSA/DH is used.
6745 If ``5'' is selected, then precomputed, fixed primes are used.
6746 This is the default for the client side.
6747 If ``1'' or ``2'' is selected, then prime values are computed during startup.
6748 The server side default is ``1''.
6749 Note: this operation can take a significant amount of time on a
6750 slow machine (several seconds), but it is only done once at startup.
6751 If ``none'' is selected, then TLS ciphersuites containing DSA/DH
6753 If a file name is specified (which must be an absolute path),
6754 then the primes are read from it.
6755 .ip DaemonPortOptions=\fIoptions\fP
6757 Set server SMTP options.
6759 .b DaemonPortOptions
6760 leads to an additional incoming socket.
6767 Name User-definable name for the daemon (defaults to "Daemon#")
6768 Port Name/number of listening port (defaults to "smtp")
6769 Addr Address mask (defaults INADDR_ANY)
6770 Family Address family (defaults to INET)
6771 InputMailFilters List of input mail filters for the daemon
6772 Listen Size of listen queue (defaults to 10)
6773 Modifier Options (flags) for the daemon
6774 SndBufSize Size of TCP send buffer
6775 RcvBufSize Size of TCP receive buffer
6776 children maximum number of children per daemon, see \fBMaxDaemonChildren\fP.
6777 DeliveryMode Delivery mode per daemon, see \fBDeliveryMode\fP.
6778 refuseLA RefuseLA per daemon
6779 delayLA DelayLA per daemon
6780 queueLA QueueLA per daemon
6784 key is used for error messages and logging.
6787 mask may be a numeric address in IPv4 dot notation or IPv6 colon notation
6789 Note that if a network name is specified,
6790 only the first IP address returned for it will be used.
6791 This may cause indeterminate behavior for network names
6792 that resolve to multiple addresses.
6793 Therefore, use of an address is recommended.
6796 key defaults to INET (IPv4).
6797 IPv6 users who wish to also accept IPv6 connections
6798 should add additional Family=inet6
6799 .b DaemonPortOptions
6803 key overrides the default list of input mail filters listed in the
6806 If multiple input mail filters are required, they must be separated
6807 by semicolons (not commas).
6809 can be a sequence (without any delimiters)
6810 of the following characters:
6813 a always require authentication
6814 b bind to interface through which mail has been received
6815 c perform hostname canonification (.cf)
6816 f require fully qualified hostname (.cf)
6817 s Run smtps (SMTP over SSL) instead of smtp
6818 u allow unqualified addresses (.cf)
6819 A disable AUTH (overrides 'a' modifier)
6820 C don't perform hostname canonification
6821 E disallow ETRN (see RFC 2476)
6822 O optional; if opening the socket fails ignore it
6823 S don't offer STARTTLS
6825 That is, one way to specify a message submission agent (MSA) that
6826 always requires authentication is:
6828 O DaemonPortOptions=Name=MSA, Port=587, M=Ea
6830 The modifiers that are marked with "(.cf)" have only
6831 effect in the standard configuration file, in which
6832 they are available via
6833 .b ${daemon_flags} .
6836 use the ``a'' modifier on a public accessible MTA!
6837 It should only be used for a MSA that is accessed by authorized
6838 users for initial mail submission.
6839 Users must authenticate to use a MSA which has this option turned on.
6840 The flags ``c'' and ``C'' can change the default for
6841 hostname canonification in the
6844 See the relevant documentation for
6845 .sm FEATURE(nocanonify) .
6846 The modifier ``f'' disallows addresses of the form
6848 unless they are submitted directly.
6849 The flag ``u'' allows unqualified sender addresses,
6850 i.e., those without @host.
6851 ``b'' forces sendmail to bind to the interface
6852 through which the e-mail has been
6853 received for the outgoing connection.
6856 only if outgoing mail can be routed through the incoming connection's
6857 interface to its destination. No attempt is made to catch problems due to a
6858 misconfiguration of this parameter, use it only for virtual hosting
6859 where each virtual interface can connect to every possible location.
6860 This will also override possible settings via
6861 .b ClientPortOptions.
6864 will listen on a new socket
6865 for each occurence of the
6866 .b DaemonPortOptions
6867 option in a configuration file.
6868 The modifier ``O'' causes sendmail to ignore a socket
6869 if it can't be opened.
6870 This applies to failures from the socket(2) and bind(2) calls.
6873 Filename that contains default authentication information for outgoing
6874 connections. This file must contain the user id, the authorization id,
6875 the password (plain text), the realm and the list of mechanisms to use
6876 on separate lines and must be readable by
6877 root (or the trusted user) only.
6878 If no realm is specified,
6881 If no mechanisms are specified, the list given by
6884 Notice: this option is deprecated and will be removed in future versions.
6885 Moreover, it doesn't work for the MSP since it can't read the file
6886 (the file must not be group/world-readable otherwise
6889 Use the authinfo ruleset instead which provides more control over
6890 the usage of the data anyway.
6891 .ip DefaultCharSet=\fIcharset\fP
6893 When a message that has 8-bit characters but is not in MIME format
6894 is converted to MIME
6895 (see the EightBitMode option)
6896 a character set must be included in the Content-Type: header.
6897 This character set is normally set from the Charset= field
6898 of the mailer descriptor.
6899 If that is not set, the value of this option is used.
6900 If this option is not set, the value
6903 .ip DataFileBufferSize=\fIthreshold\fP
6908 before a memory-based
6911 The default is 4096 bytes.
6912 .ip DeadLetterDrop=\fIfile\fP
6914 Defines the location of the system-wide dead.letter file,
6915 formerly hardcoded to /usr/tmp/dead.letter.
6916 If this option is not set (the default),
6917 sendmail will not attempt to save to a system-wide dead.letter file
6919 it cannot bounce the mail to the user or postmaster.
6920 Instead, it will rename the qf file
6921 as it has in the past
6922 when the dead.letter file could not be opened.
6923 .ip DefaultUser=\fIuser:group\fP
6925 Set the default userid for mailers to
6932 (as opposed to a numeric user id)
6933 the default group listed in the /etc/passwd file for that user is used
6934 as the default group.
6942 flag in the mailer definition
6943 will run as this user.
6945 The value can also be given as a symbolic user name.\**
6949 option has been combined into the
6953 .ip DelayLA=\fILA\fP
6955 When the system load average exceeds
6958 will sleep for one second on most SMTP commands and
6959 before accepting connections.
6960 .ip DeliverByMin=\fItime\fP
6962 Set minimum time for Deliver By SMTP Service Extension (RFC 2852).
6963 If 0, no time is listed, if less than 0, the extension is not offered,
6964 if greater than 0, it is listed as minimum time
6965 for the EHLO keyword DELIVERBY.
6966 .ip DeliveryMode=\fIx\fP
6973 i Deliver interactively (synchronously)
6974 b Deliver in background (asynchronously)
6975 q Just queue the message (deliver during queue run)
6976 d Defer delivery and all map lookups (deliver during queue run)
6978 Defaults to ``b'' if no option is specified,
6979 ``i'' if it is specified but given no argument
6980 (i.e., ``Od'' is equivalent to ``Odi'').
6983 command line flag sets this to
6985 Note: for internal reasons,
6987 if a milter is enabled which can reject or delete recipients.
6988 In that case the mode will be changed to ``b''.
6989 .ip DialDelay=\fIsleeptime\fP
6991 Dial-on-demand network connections can see timeouts
6992 if a connection is opened before the call is set up.
6993 If this is set to an interval and a connection times out
6994 on the first connection being attempted
6996 will sleep for this amount of time and try again.
6997 This should give your system time to establish the connection
6998 to your service provider.
6999 Units default to seconds, so
7001 uses a five second delay.
7004 This delay only applies to mailers which have the
7006 .ip DirectSubmissionModifiers=\fImodifiers\fP
7009 for direct (command line) submissions.
7012 is either "CC f" if the option
7014 is used or "c u" otherwise.
7015 Note that only the the "CC", "c", "f", and "u" flags are checked.
7016 .ip DontBlameSendmail=\fIoption,option,...\fP
7018 In order to avoid possible cracking attempts
7019 caused by world- and group-writable files and directories,
7021 does paranoid checking when opening most of its support files.
7022 If for some reason you absolutely must run with,
7027 then you will have to turn off this checking
7028 (at the cost of making your system more vulnerable to attack).
7029 The possible arguments have been described earlier.
7030 The details of these flags are described above.
7031 .\"XXX should have more here!!! XXX
7032 .b "Use of this option is not recommended."
7033 .ip DontExpandCnames
7035 The standards say that all host addresses used in a mail message
7036 must be fully canonical.
7037 For example, if your host is named
7039 and also has an alias of
7041 the former name must be used at all times.
7042 This is enforced during host name canonification
7043 ($[ ... $] lookups).
7044 If this option is set, the protocols are ignored and the
7047 However, the IETF is moving toward changing this standard,
7048 so the behavior may become acceptable.
7049 Please note that hosts downstream may still rewrite the address
7050 to be the true canonical name however.
7055 will avoid using the initgroups(3) call.
7056 If you are running NIS,
7057 this causes a sequential scan of the groups.byname map,
7058 which can cause your NIS server to be badly overloaded in a large domain.
7059 The cost of this is that the only group found for users
7060 will be their primary group (the one in the password file),
7061 which will make file access permissions somewhat more restrictive.
7062 Has no effect on systems that don't have group lists.
7063 .ip DontProbeInterfaces
7066 normally finds the names of all interfaces active on your machine
7068 and adds their name to the
7070 class of known host aliases.
7071 If you have a large number of virtual interfaces
7072 or if your DNS inverse lookups are slow
7073 this can be time consuming.
7074 This option turns off that probing.
7075 However, you will need to be certain to include all variant names
7078 class by some other mechanism.
7081 loopback interfaces (e.g., lo0) will not be probed.
7086 tries to eliminate any unnecessary explicit routes
7087 when sending an error message
7088 (as discussed in RFC 1123 \(sc 5.2.6).
7090 when sending an error message to
7092 <@known1,@known2,@known3:user@unknown>
7097 in order to make the route as direct as possible.
7100 option is set, this will be disabled,
7101 and the mail will be sent to the first address in the route,
7102 even if later addresses are known.
7103 This may be useful if you are caught behind a firewall.
7104 .ip DoubleBounceAddress=\fIerror-address\fP
7106 If an error occurs when sending an error message,
7107 send the error report
7110 because it is an error
7112 that occurs when trying to send another error
7114 to the indicated address.
7115 The address is macro expanded
7116 at the time of delivery.
7117 If not set, defaults to
7119 If set to an empty string, double bounces are dropped.
7120 .ip EightBitMode=\fIaction\fP
7122 Set handling of eight-bit data.
7123 There are two kinds of eight-bit data:
7124 that declared as such using the
7126 ESMTP declaration or the
7129 and undeclared 8-bit data, that is,
7130 input that just happens to be eight bits.
7131 There are three basic operations that can happen:
7132 undeclared 8-bit data can be automatically converted to 8BITMIME,
7133 undeclared 8-bit data can be passed as-is without conversion to MIME
7135 and declared 8-bit data can be converted to 7-bits
7136 for transmission to a non-8BITMIME mailer.
7141 .\" r Reject undeclared 8-bit data;
7142 .\" don't convert 8BITMIME\(->7BIT (``reject'')
7143 s Reject undeclared 8-bit data (``strict'')
7144 .\" do convert 8BITMIME\(->7BIT (``strict'')
7145 .\" c Convert undeclared 8-bit data to MIME;
7146 .\" don't convert 8BITMIME\(->7BIT (``convert'')
7147 m Convert undeclared 8-bit data to MIME (``mime'')
7148 .\" do convert 8BITMIME\(->7BIT (``mime'')
7149 .\" j Pass undeclared 8-bit data;
7150 .\" don't convert 8BITMIME\(->7BIT (``just send 8'')
7151 p Pass undeclared 8-bit data (``pass'')
7152 .\" do convert 8BITMIME\(->7BIT (``pass'')
7153 .\" a Adaptive algorithm: see below
7155 .\"The adaptive algorithm is to accept 8-bit data,
7156 .\"converting it to 8BITMIME only if the receiver understands that,
7157 .\"otherwise just passing it as undeclared 8-bit data;
7158 .\"8BITMIME\(->7BIT conversions are done.
7159 In all cases properly declared 8BITMIME data will be converted to 7BIT
7161 .ip ErrorHeader=\fIfile-or-message\fP
7163 Prepend error messages with the indicated message.
7164 If it begins with a slash,
7165 it is assumed to be the pathname of a file
7166 containing a message (this is the recommended setting).
7167 Otherwise, it is a literal message.
7168 The error file might contain the name, email address, and/or phone number
7169 of a local postmaster who could provide assistance
7171 If the option is missing or null,
7172 or if it names a file which does not exist or which is not readable,
7173 no message is printed.
7174 .ip ErrorMode=\fIx\fP
7176 Dispose of errors using mode
7182 p Print error messages (default)
7183 q No messages, just give exit status
7185 w Write back errors (mail if user not logged in)
7186 e Mail back errors (when applicable) and give zero exit stat always
7188 Note that the last mode,
7190 is for Berknet error processing and
7191 should not be used in normal circumstances.
7192 Note, too, that mode
7194 only applies to errors recognized before sendmail forks for
7195 background delivery.
7196 .ip FallbackMXhost=\fIfallbackhost\fP
7200 acts like a very low priority MX
7202 MX records will be looked up for this host,
7203 unless the name is surrounded by square brackets.
7204 This is intended to be used by sites with poor network connectivity.
7205 Messages which are undeliverable due to temporary address failures
7207 also go to the FallbackMXhost.
7208 .ip FallBackSmartHost=\fIhostname\fP
7210 .i FallBackSmartHost
7211 will be used in a last-ditch effort for each host.
7212 This is intended to be used by sites with "fake internal DNS",
7213 e.g., a company whose DNS accurately reflects the world
7214 inside that company's domain but not outside.
7217 If set to a value greater than zero (the default is one),
7218 it suppresses the MX lookups on addresses
7219 when they are initially sorted, i.e., for the first delivery attempt.
7220 This usually results in faster envelope splitting unless the MX records
7221 are readily available in a local DNS cache.
7222 To enforce initial sorting based on MX records set
7225 If the mail is submitted directly from the command line, then
7226 the value also limits the number of processes to deliver the envelopes;
7227 if more envelopes are created they are only queued up
7228 and must be taken care of by a queue run.
7229 Since the default submission method is via SMTP (either from a MUA
7230 or via the MSP), the value of
7232 is seldom used to limit the number of processes to deliver the envelopes.
7236 deliver each job that is run from the queue in a separate process.
7237 .ip ForwardPath=\fIpath\fP
7239 Set the path for searching for users' .forward files.
7242 Some sites that use the automounter may prefer to change this to
7244 to search a file with the same name as the user in a system directory.
7245 It can also be set to a sequence of paths separated by colons;
7247 stops at the first file it can successfully and safely open.
7249 .q /var/forward/$u:$z/.forward
7250 will search first in /var/forward/\c
7253 .i ~username /.forward
7254 (but only if the first file does not exist).
7255 .ip HeloName=\fIname\fP
7257 Set the name to be used for HELO/EHLO (instead of $j).
7260 If an outgoing mailer is marked as being expensive,
7261 don't connect immediately.
7262 .ip HostsFile=\fIpath\fP
7264 The path to the hosts database,
7267 This option is only consulted when sendmail
7268 is canonifying addresses,
7273 service switch entry.
7274 In particular, this file is
7276 used when looking up host addresses;
7277 that is under the control of the system
7278 .i gethostbyname (3)
7280 .ip HostStatusDirectory=\fIpath\fP
7282 The location of the long term host status information.
7284 information about the status of hosts
7285 (e.g., host down or not accepting connections)
7286 will be shared between all
7289 normally, this information is only held within a single queue run.
7290 This option requires a connection cache of at least 1 to function.
7291 If the option begins with a leading `/',
7292 it is an absolute pathname;
7294 it is relative to the mail queue directory.
7295 A suggested value for sites desiring persistent host status is
7297 (i.e., a subdirectory of the queue directory).
7300 Ignore dots in incoming messages.
7301 This is always disabled (that is, dots are always accepted)
7302 when reading SMTP mail.
7303 .ip InputMailFilters=\fIname,name,...\fP
7304 A comma separated list of filters which determines which filters
7305 (see the "X \*- Mail Filter (Milter) Definitions" section)
7306 and the invocation sequence are contacted for incoming SMTP messages.
7307 If none are set, no filters will be contacted.
7308 .ip LDAPDefaultSpec=\fIspec\fP
7310 Sets a default map specification for LDAP maps.
7311 The value should only contain LDAP specific settings
7313 .q "-h host -p port -d bindDN" .
7314 The settings will be used for all LDAP maps
7315 unless the individual map specification overrides a setting.
7316 This option should be set before any LDAP maps are defined.
7317 .ip LogLevel=\fIn\fP
7319 Set the log level to
7328 This is intended only for use from the command line.
7334 Type of lookup to find information about local mailboxes,
7335 defaults to ``pw'' which uses
7337 Other types can be introduced by adding them to the source code,
7338 see libsm/mbdb.c for details.
7341 Use as mail submission program, i.e.,
7342 allow group writable queue files
7343 if the group is the same as that of a set-group-ID sendmail binary.
7345 .b sendmail/SECURITY
7346 in the distribution tarball.
7349 Allow fuzzy matching on the GECOS field.
7350 If this flag is set,
7351 and the usual user name lookups fail
7352 (that is, there is no alias with this name and a
7355 sequentially search the password file
7356 for a matching entry in the GECOS field.
7357 This also requires that MATCHGECOS
7358 be turned on during compilation.
7359 This option is not recommended.
7360 .ip MaxAliasRecursion=\fIN\fP
7362 The maximum depth of alias recursion (default: 10).
7363 .ip MaxDaemonChildren=\fIN\fP
7367 will refuse connections when it has more than
7369 children processing incoming mail or automatic queue runs.
7370 This does not limit the number of outgoing connections.
7373 (background) is used, then
7375 may create an almost unlimited number of children
7376 (depending on the number of transactions and the
7377 relative execution times of mail receiption and mail delivery).
7378 If the limit should be enforced, then a
7380 other than background must be used.
7381 If not set, there is no limit to the number of children --
7382 that is, the system load average controls this.
7383 .ip MaxHeadersLength=\fIN\fP
7385 The maximum length of the sum of all headers.
7386 This can be used to prevent a denial of service attack.
7387 The default is no limit.
7388 .ip MaxHopCount=\fIN\fP
7390 The maximum hop count.
7391 Messages that have been processed more than
7393 times are assumed to be in a loop and are rejected.
7395 .ip MaxMessageSize=\fIN\fP
7397 Specify the maximum message size
7398 to be advertised in the ESMTP EHLO response.
7399 Messages larger than this will be rejected.
7400 If set to a value greater than zero,
7401 that value will be listed in the SIZE response,
7402 otherwise SIZE is advertised in the ESMTP EHLO response
7403 without a parameter.
7404 .ip MaxMimeHeaderLength=\fIN[/M]\fP
7406 Sets the maximum length of certain MIME header field values to
7409 These MIME header fields are determined by being a member of
7410 class {checkMIMETextHeaders}, which currently contains only
7411 the header Content-Description.
7412 For some of these headers which take parameters,
7413 the maximum length of each parameter is set to
7417 is not specified, one half of
7421 these values are 2048 and 1024, respectively.
7422 To allow any length, a value of 0 can be specified.
7423 .ip MaxNOOPCommands=\fIN\fP
7424 Override the default of
7428 commands, see Section
7429 "Measures against Denial of Service Attacks".
7430 .ip MaxQueueChildren=\fIN\fP
7432 When set, this limits the number of concurrent queue runner processes to
7434 This helps to control the amount of system resources used when processing
7435 the queue. When there are multiple queue groups defined and the total number
7436 of queue runners for these queue groups would exceed
7438 then the queue groups will not all run concurrently. That is, some portion
7439 of the queue groups will run concurrently such that
7441 will not be exceeded, while the remaining queue groups will be run later (in
7442 round robin order). See also
7443 .i MaxRunnersPerQueue
7444 and the section \fBQueue Group Declaration\fP.
7447 does not count individual queue runners, but only sets of processes
7448 that act on a workgroup.
7449 Hence the actual number of queue runners may be lower than the limit
7451 .i MaxQueueChildren .
7452 This discrepancy can be large if some queue runners have to wait
7453 for a slow server and if short intervals are used.
7454 .ip MaxQueueRunSize=\fIN\fP
7456 The maximum number of jobs that will be processed
7457 in a single queue run.
7458 If not set, there is no limit on the size.
7459 If you have very large queues or a very short queue run interval
7460 this could be unstable.
7461 However, since the first
7463 jobs in queue directory order are run (rather than the
7465 highest priority jobs)
7466 this should be set as high as possible to avoid
7468 jobs that happen to fall late in the queue directory.
7469 Note: this option also restricts the number of entries printed by
7478 entries are printed per queue group.
7479 .ip MaxRecipientsPerMessage=\fIN\fP
7481 The maximum number of recipients that will be accepted per message
7482 in an SMTP transaction.
7483 Note: setting this too low can interfere with sending mail from
7484 MUAs that use SMTP for initial submission.
7485 If not set, there is no limit on the number of recipients per envelope.
7486 .ip MaxRunnersPerQueue=\fIN\fP
7488 This sets the default maximum number of queue runners for queue groups.
7491 queue runners will work in parallel on a queue group's messages.
7492 This is useful where the processing of a message in the queue might
7493 delay the processing of subsequent messages. Such a delay may be the result
7494 of non-erroneous situations such as a low bandwidth connection.
7495 May be overridden on a per queue group basis by setting the
7497 option; see the section \fBQueue Group Declaration\fP.
7498 The default is 1 when not set.
7502 even if I am in an alias expansion.
7503 This option is deprecated
7504 and will be removed from a future version.
7507 This option has several sub(sub)options.
7508 The names of the suboptions are separated by dots.
7509 At the first level the following options are available:
7511 .ta \w'LogLevel'u+3n
7512 LogLevel Log level for input mail filter actions, defaults to LogLevel.
7513 macros Specifies list of macro to transmit to filters.
7516 The ``macros'' option has the following suboptions
7517 which specify the list of macro to transmit to milters
7518 after a certain event occurred.
7521 connect After session connection start
7522 helo After EHLO/HELO command
7523 envfrom After MAIL From command
7524 envrcpt After RCPT To command
7525 data After DATA command.
7526 eoh After DATA command and header
7527 eom After DATA command and terminating ``.''
7529 By default the lists of macros are empty.
7532 O Milter.LogLevel=12
7533 O Milter.macros.connect=j, _, {daemon_name}
7535 .ip MinFreeBlocks=\fIN\fP
7539 blocks free on the filesystem that holds the queue files
7540 before accepting email via SMTP.
7541 If there is insufficient space
7543 gives a 452 response
7544 to the MAIL command.
7545 This invites the sender to try again later.
7546 .ip MinQueueAge=\fIage\fP
7548 Don't process any queued jobs
7549 that have been in the queue less than the indicated time interval.
7550 This is intended to allow you to get responsiveness
7551 by processing the queue fairly frequently
7552 without thrashing your system by trying jobs too often.
7553 The default units are minutes.
7555 This option is ignored for queue runs that select a subset
7557 .q \-q[!][I|R|S|Q][string]
7558 .ip MustQuoteChars=\fIs\fP
7560 Sets the list of characters that must be quoted if used in a full name
7561 that is in the phrase part of a ``phrase <address>'' syntax.
7562 The default is ``\'.''.
7563 The characters ``@,;:\e()[]'' are always added to this list.
7566 The priority of queue runners (nice(3)).
7567 This value must be greater or equal zero.
7568 .ip NoRecipientAction
7570 The action to take when you receive a message that has no valid
7571 recipient headers (To:, Cc:, Bcc:, or Apparently-To: \(em
7572 the last included for back compatibility with old
7576 to pass the message on unmodified,
7577 which violates the protocol,
7579 to add a To: header with any recipients it can find in the envelope
7580 (which might expose Bcc: recipients),
7581 .b Add-Apparently-To
7582 to add an Apparently-To: header
7583 (this is only for back-compatibility
7584 and is officially deprecated),
7585 .b Add-To-Undisclosed
7587 .q "To: undisclosed-recipients:;"
7588 to make the header legal without disclosing anything,
7591 to add an empty Bcc: header.
7594 Assume that the headers may be in old format,
7596 spaces delimit names.
7597 This actually turns on
7598 an adaptive algorithm:
7599 if any recipient address contains a comma, parenthesis,
7601 it will be assumed that commas already exist.
7602 If this flag is not on,
7603 only commas delimit names.
7604 Headers are always output with commas between the names.
7606 .ip OperatorChars=\fIcharlist\fP
7608 The list of characters that are considered to be
7610 that is, characters that delimit tokens.
7611 All operator characters are tokens by themselves;
7612 sequences of non-operator characters are also tokens.
7613 White space characters separate tokens
7614 but are not tokens themselves \(em for example,
7616 has three tokens, but
7619 If not set, OperatorChars defaults to
7620 .q \&.\|:\|@\|[\|] ;
7621 additionally, the characters
7623 are always operators.
7624 Note that OperatorChars must be set in the
7625 configuration file before any rulesets.
7626 .ip PidFile=\fIfilename\fP
7628 Filename of the pid file.
7629 (default is _PATH_SENDMAILPID).
7632 is macro-expanded before it is opened, and unlinked when
7635 .ip PostmasterCopy=\fIpostmaster\fP
7638 copies of error messages will be sent to the named
7640 Only the header of the failed message is sent.
7641 Errors resulting from messages with a negative precedence will not be sent.
7642 Since most errors are user problems,
7643 this is probably not a good idea on large sites,
7644 and arguably contains all sorts of privacy violations,
7645 but it seems to be popular with certain operating systems vendors.
7646 The address is macro expanded
7647 at the time of delivery.
7648 Defaults to no postmaster copies.
7649 .ip PrivacyOptions=\fI\|opt,opt,...\fP
7653 ``Privacy'' is really a misnomer;
7654 many of these are just a way of insisting on stricter adherence
7655 to the SMTP protocol.
7658 can be selected from:
7660 .ta \w'noactualrecipient'u+3n
7661 public Allow open access
7662 needmailhelo Insist on HELO or EHLO command before MAIL
7663 needexpnhelo Insist on HELO or EHLO command before EXPN
7664 noexpn Disallow EXPN entirely, implies noverb.
7665 needvrfyhelo Insist on HELO or EHLO command before VRFY
7666 novrfy Disallow VRFY entirely
7667 noetrn Disallow ETRN entirely
7668 noverb Disallow VERB entirely
7669 restrictmailq Restrict mailq command
7670 restrictqrun Restrict \-q command line flag
7671 restrictexpand Restrict \-bv and \-v command line flags
7672 noreceipts Don't return success DSNs\**
7673 nobodyreturn Don't return the body of a message with DSNs
7674 goaway Disallow essentially all SMTP status queries
7675 authwarnings Put X-Authentication-Warning: headers in messages
7677 noactualrecipient Don't put X-Actual-Recipient lines in DSNs
7678 which reveal the actual account that addresses map to.
7684 flag turns off support for RFC 1891
7685 (Delivery Status Notification).
7689 pseudo-flag sets all flags except
7697 If mailq is restricted,
7698 only people in the same group as the queue directory
7699 can print the queue.
7700 If queue runs are restricted,
7701 only root and the owner of the queue directory
7705 pseudo-flag instructs
7707 to drop privileges when the
7709 option is given by users who are neither root nor the TrustedUser
7710 so users cannot read private aliases, forwards, or :include: files.
7714 .q DontBlameSendmail
7715 option to prevent misleading unsafe address warnings.
7716 It also overrides the
7718 (verbose) command line option to prevent information leakage.
7719 Authentication Warnings add warnings about various conditions
7720 that may indicate attempts to spoof the mail system,
7721 such as using a non-standard queue directory.
7722 .ip ProcessTitlePrefix=\fIstring\fP
7724 Prefix the process title shown on 'ps' listings with
7728 will be macro processed.
7729 .ip QueueDirectory=\fIdir\fP
7731 The QueueDirectory option serves two purposes.
7732 First, it specifies the directory or set of directories that comprise
7733 the default queue group.
7734 Second, it specifies the directory D which is the ancestor of all queue
7735 directories, and which sendmail uses as its current working directory.
7736 When sendmail dumps core, it leaves its core files in D.
7737 There are two cases.
7738 If \fIdir\fR ends with an asterisk (eg, \fI/var/spool/mqueue/qd*\fR),
7739 then all of the directories or symbolic links to directories
7740 beginning with `qd' in
7741 .i /var/spool/mqueue
7742 will be used as queue directories of the default queue group,
7744 .i /var/spool/mqueue
7745 will be used as the working directory D.
7747 \fIdir\fR must name a directory (usually \fI/var/spool/mqueue\fR):
7748 the default queue group consists of the single queue directory \fIdir\fR,
7749 and the working directory D is set to \fIdir\fR.
7750 To define additional groups of queue directories,
7751 use the configuration file `Q' command.
7752 Do not change the queue directory structure
7753 while sendmail is running.
7754 .ip QueueFactor=\fIfactor\fP
7758 as the multiplier in the map function
7759 to decide when to just queue up jobs rather than run them.
7760 This value is divided by the difference between the current load average
7761 and the load average limit
7765 to determine the maximum message priority
7768 .ip QueueLA=\fILA\fP
7770 When the system load average exceeds
7776 option divided by the difference in the current load average and the
7779 is less than the priority of the message,
7781 (i.e., don't try to send them).
7782 Defaults to 8 multiplied by
7783 the number of processors online on the system
7784 (if that can be determined).
7785 .ip QueueFileMode=\fImode\fP
7787 Default permissions for queue files (octal).
7788 If not set, sendmail uses 0600 unless its real
7789 and effective uid are different in which case it uses 0644.
7790 .ip QueueSortOrder=\fIalgorithm\fP
7794 used for sorting the queue.
7795 Only the first character of the value is used.
7798 (to order by the name of the first host name of the first recipient),
7800 (to order by the name of the queue file name),
7802 (to order by the submission/creation time),
7804 (to order randomly),
7806 (to order by the modification time of the qf file (older entries first)),
7811 (to order by message priority).
7812 Host ordering makes better use of the connection cache,
7813 but may tend to process low priority messages
7814 that go to a single host
7815 over high priority messages that go to several hosts;
7816 it probably shouldn't be used on slow network links.
7817 Filename and modification time ordering saves the overhead of
7818 reading all of the queued items
7819 before starting the queue run.
7820 Creation (submission) time ordering is almost always a bad idea,
7821 since it allows large, bulk mail to go out
7822 before smaller, personal mail,
7823 but may have applicability on some hosts with very fast connections.
7824 Random is useful if several queue runners are started by hand
7825 which try to drain the same queue since odds are they will be working
7826 on different parts of the queue at the same time.
7827 Priority ordering is the default.
7828 .ip QueueTimeout=\fItimeout\fP
7831 .q Timeout.queuereturn .
7832 Use that form instead of the
7837 Name of file containing random data or the name of the UNIX socket
7839 A (required) prefix "egd:" or "file:" specifies the type.
7840 STARTTLS requires this filename if the compile flag HASURANDOMDEV is not set
7841 (see sendmail/README).
7842 .ip ResolverOptions=\fIoptions\fP
7844 Set resolver options.
7845 Values can be set using
7871 can be specified to turn off matching against MX records
7872 when doing name canonifications.
7874 .q WorkAroundBrokenAAAA
7879 can be specified to work around some broken nameservers
7880 which return SERVFAIL (a temporary failure) on T_AAAA (IPv6) lookups.
7881 Notice: it might be necessary to apply the same (or similar) options to
7884 .ip RequiresDirfsync
7886 This option can be used to override the compile time flag
7887 .b REQUIRES_DIR_FSYNC
7888 at runtime by setting it to
7890 If the compile time flag is not set, the option is ignored.
7891 The flag turns on support for file systems that require to call
7893 for a directory if the meta-data in it has been changed.
7894 This should be turned on at least for older versions of ReiserFS;
7895 it is enabled by default for Linux.
7896 According to some information this flag is not needed
7897 anymore for kernel 2.4.16 and newer.
7900 If this option is set, a
7901 .q Return-Receipt-To:
7902 header causes the request of a DSN, which is sent to
7903 the envelope sender as required by RFC 1891,
7904 not to the address given in the header.
7905 .ip RunAsUser=\fIuser\fP
7909 parameter may be a user name
7912 or a numeric user id;
7913 either form can have
7916 (where group can be numeric or symbolic).
7917 If set to a non-zero (non-root) value,
7919 will change to this user id shortly after startup\**.
7921 \**When running as a daemon,
7922 it changes to this user after accepting a connection
7923 but before reading any
7927 This avoids a certain class of security problems.
7928 However, this means that all
7932 files must be readable by the indicated
7934 and all files to be written must be writable by
7936 Also, all file and program deliveries will be marked unsafe
7938 .b DontBlameSendmail=NonRootSafeAddr
7940 in which case the delivery will be done as
7942 It is also incompatible with the
7943 .b SafeFileEnvironment
7945 In other words, it may not actually add much to security on an average system,
7946 and may in fact detract from security
7947 (because other file permissions must be loosened).
7948 However, it should be useful on firewalls and other
7949 places where users don't have accounts and the aliases file is
7951 .ip RecipientFactor=\fIfact\fP
7955 is added to the priority (thus
7957 the priority of the job)
7959 i.e., this value penalizes jobs with large numbers of recipients.
7961 .ip RefuseLA=\fILA\fP
7963 When the system load average exceeds
7965 refuse incoming SMTP connections.
7966 Defaults to 12 multiplied by
7967 the number of processors online on the system
7968 (if that can be determined).
7969 .ip RejectLogInterval=\fItimeout\fP
7971 Log interval when refusing connections for this long
7973 .ip RetryFactor=\fIfact\fP
7977 is added to the priority
7978 every time a job is processed.
7980 each time a job is processed,
7981 its priority will be decreased by the indicated value.
7982 In most environments this should be positive,
7983 since hosts that are down are all too often down for a long time.
7985 .ip SafeFileEnvironment=\fIdir\fP
7987 If this option is set,
7991 call into the indicated
7993 before doing any file writes.
7994 If the file name specified by the user begins with
7996 that partial path name will be stripped off before writing,
7998 if the SafeFileEnvironment variable is set to
8004 actually indicate the same file.
8005 Additionally, if this option is set,
8007 refuses to deliver to symbolic links.
8013 lines at the front of headers.
8014 Normally they are assumed redundant
8018 If set, send error messages in MIME format
8019 (see RFC 2045 and RFC 1344 for details).
8022 will not return the DSN keyword in response to an EHLO
8023 and will not do Delivery Status Notification processing as described in
8027 File containing the certificate of the server, i.e., this certificate
8028 is used when sendmail acts as server
8029 (used for STARTTLS).
8032 File containing the private key belonging to the server certificate
8033 (used for STARTTLS).
8034 .ip ServiceSwitchFile=\fIfilename\fP
8036 If your host operating system has a service switch abstraction
8037 (e.g., /etc/nsswitch.conf on Solaris
8038 or /etc/svc.conf on Ultrix and DEC OSF/1)
8039 that service will be consulted and this option is ignored.
8040 Otherwise, this is the name of a file
8041 that provides the list of methods used to implement particular services.
8042 The syntax is a series of lines,
8043 each of which is a sequence of words.
8044 The first word is the service name,
8045 and following words are service types.
8048 consults directly are
8052 Service types can be
8058 (with the caveat that the appropriate support
8060 before the service can be referenced).
8061 If ServiceSwitchFile is not specified, it defaults to
8062 /etc/mail/service.switch.
8063 If that file does not exist, the default switch is:
8069 .q /etc/mail/service.switch .
8072 Strip input to seven bits for compatibility with old systems.
8073 This shouldn't be necessary.
8076 Key to use for shared memory segment;
8077 if not set (or 0), shared memory will not be used.
8081 can select a key itself provided that also
8082 .b SharedMemoryKeyFile
8084 Requires support for shared memory to be compiled into
8086 If this option is set,
8088 can share some data between different instances.
8089 For example, the number of entries in a queue directory
8090 or the available space in a file system.
8091 This allows for more efficient program execution, since only
8092 one process needs to update the data instead of each individual
8093 process gathering the data each time it is required.
8094 .ip SharedMemoryKeyFile
8100 then the automatically selected shared memory key will be stored
8101 in the specified file.
8102 .ip SingleLineFromHeader
8104 If set, From: lines that have embedded newlines are unwrapped
8106 This is to get around a botch in Lotus Notes
8107 that apparently cannot understand legally wrapped RFC 822 headers.
8108 .ip SingleThreadDelivery
8110 If set, a client machine will never try to open two SMTP connections
8111 to a single server machine at the same time,
8112 even in different processes.
8115 is already talking to some host a new
8117 will not open another connection.
8118 This property is of mixed value;
8119 although this reduces the load on the other machine,
8120 it can cause mail to be delayed
8121 (for example, if one
8123 is delivering a huge message, other
8125 won't be able to send even small messages).
8126 Also, it requires another file descriptor
8128 per connection, so you may have to reduce the
8129 .b ConnectionCacheSize
8130 option to avoid running out of per-process file descriptors.
8132 .b HostStatusDirectory
8134 .ip SmtpGreetingMessage=\fImessage\fP
8136 The message printed when the SMTP server starts up.
8138 .q "$j Sendmail $v ready at $b".
8140 If set, issue temporary errors (4xy) instead of permanent errors (5xy).
8141 This can be useful during testing of a new configuration to avoid
8142 erroneous bouncing of mails.
8143 .ip StatusFile=\fIfile\fP
8145 Log summary statistics in the named
8147 If no file name is specified, "statistics" is used.
8149 no summary statistics are saved.
8150 This file does not grow in size.
8151 It can be printed using the
8156 This option can be set to True, False, Interactive, or PostMilter.
8159 will be super-safe when running things,
8160 i.e., always instantiate the queue file,
8161 even if you are going to attempt immediate delivery.
8163 always instantiates the queue file
8164 before returning control to the client
8165 under any circumstances.
8169 The Interactive value has been introduced in 8.12 and can
8170 be used together with
8172 It skips some synchronization calls which are effectively
8173 doubled in the code execution path for this mode.
8174 If set to PostMilter,
8176 defers synchronizing the queue file until any milters have
8177 signaled acceptance of the message.
8178 PostMilter is useful only when
8180 is running as an SMTP server; in all other situations it
8181 acts the same as True.
8184 List of options for SMTP STARTTLS for the server
8185 consisting of single characters
8186 with intervening white space or commas.
8187 The flag ``V'' disables client verification, and hence
8188 it is not possible to use a client certificate for relaying.
8189 Currently there are no other flags available.
8190 .ip TempFileMode=\fImode\fP
8192 The file mode for transcript files, files to which
8194 delivers directly, files in the
8195 .b HostStatusDirectory ,
8198 It is interpreted in octal by default.
8200 .ip Timeout.\fItype\fP=\|\fItimeout\fP
8201 [r; subsumes old T option as well]
8203 For more information,
8207 .ip TimeZoneSpec=\fItzinfo\fP
8209 Set the local time zone info to
8213 Actually, if this is not set,
8214 the TZ environment variable is cleared (so the system default is used);
8215 if set but null, the user's TZ variable is used,
8216 and if set and non-null the TZ variable is set to this value.
8217 .ip TrustedUser=\fIuser\fP
8221 parameter may be a user name
8224 or a numeric user id.
8225 Trusted user for file ownership and starting the daemon. If set, generated
8226 alias databases and the control socket (if configured) will automatically
8227 be owned by this user.
8230 If this system is the
8232 (that is, lowest preference)
8233 MX for a given host,
8234 its configuration rules should normally detect this situation
8235 and treat that condition specially
8236 by forwarding the mail to a UUCP feed,
8237 treating it as local,
8239 However, in some cases (such as Internet firewalls)
8240 you may want to try to connect directly to that host
8241 as though it had no MX records at all.
8242 Setting this option causes
8245 The downside is that errors in your configuration
8246 are likely to be diagnosed as
8249 .q "message timed out"
8250 instead of something more meaningful.
8251 This option is disrecommended.
8252 .ip UnixFromLine=\fIfromline\fP
8254 Defines the format used when
8256 must add a UNIX-style From_ line
8257 (that is, a line beginning
8258 .q From<space>user ).
8261 Don't change this unless your system uses a different UNIX mailbox format
8263 .ip UnsafeGroupWrites
8266 :include: and .forward files that are group writable are considered
8269 they cannot reference programs or write directly to files.
8270 World writable :include: and .forward files
8273 .b DontBlameSendmail
8274 instead; this option is deprecated.
8279 header, send error messages to the addresses listed there.
8280 They normally go to the envelope sender.
8281 Use of this option causes
8283 to violate RFC 1123.
8284 This option is disrecommended and deprecated.
8285 .ip UserDatabaseSpec=\fIudbspec\fP
8287 The user database specification.
8290 Run in verbose mode.
8301 so that all mail is delivered completely
8303 so that you can see the entire delivery process.
8308 be set in the configuration file;
8309 it is intended for command line use only.
8310 Note that the use of option
8312 can cause authentication information to leak, if you use a
8313 sendmail client to authenticate to a server.
8314 If the authentication mechanism uses plain text passwords
8315 (as with LOGIN or PLAIN),
8316 then the password could be compromised.
8317 To avoid this, do not install sendmail set-user-ID root,
8320 SMTP command with a suitable
8323 .ip XscriptFileBufferSize=\fIthreshold\fP
8328 before a memory-based
8329 queue transcript file
8331 The default is 4096 bytes.
8333 All options can be specified on the command line using the
8337 to relinquish its set-user-ID permissions.
8338 The options that will not cause this are
8342 CheckpointInterval [C],
8349 OldStyleHeaders [o],
8360 SingleLineFromHeader,
8363 Actually, PrivacyOptions [p] given on the command line
8364 are added to those already specified in the
8366 file, i.e., they can't be reset.
8367 Also, M (define macro) when defining the r or s macros
8370 .sh 2 "P \*- Precedence Definitions"
8374 field may be defined using the
8377 The syntax of this field is:
8379 \fBP\fP\fIname\fP\fB=\fP\fInum\fP
8386 the message class is set to
8388 Higher numbers mean higher precedence.
8389 Numbers less than zero
8390 have the special property
8391 that if an error occurs during processing
8392 the body of the message will not be returned;
8393 this is expected to be used for
8395 mail such as through mailing lists.
8396 The default precedence is zero.
8398 our list of precedences is:
8401 Pspecial-delivery=100
8406 People writing mailing list exploders
8407 are encouraged to use
8408 .q "Precedence: list" .
8411 (which discarded all error returns for negative precedences)
8412 didn't recognize this name, giving it a default precedence of zero.
8413 This allows list maintainers to see error returns
8414 on both old and new versions of
8416 .sh 2 "V \*- Configuration Version Level"
8418 To provide compatibility with old configuration files,
8421 line has been added to define some very basic semantics
8422 of the configuration file.
8423 These are not intended to be long term supports;
8424 rather, they describe compatibility features
8425 which will probably be removed in future releases.
8431 to do with the version
8436 version 10 config files
8437 (specifically, 8.10)
8438 used version level 9 configurations.
8441 configuration files are defined as version level one.
8442 Version level two files make the following changes:
8444 Host name canonification ($[ ... $])
8445 appends a dot if the name is recognized;
8446 this gives the config file a way of finding out if anything matched.
8447 (Actually, this just initializes the
8451 flag \*- you can reset it to anything you prefer
8452 by declaring the map explicitly.)
8454 Default host name extension is consistent throughout processing;
8455 version level one configurations turned off domain extension
8456 (that is, adding the local domain name)
8457 during certain points in processing.
8458 Version level two configurations are expected to include a trailing dot
8459 to indicate that the name is already canonical.
8461 Local names that are not aliases
8462 are passed through a new distinguished ruleset five;
8463 this can be used to append a local relay.
8464 This behavior can be prevented by resolving the local name
8465 with an initial `@'.
8466 That is, something that resolves to a local mailer and a user name of
8468 will be passed through ruleset five,
8471 will have the `@' stripped,
8472 will not be passed through ruleset five,
8473 but will otherwise be treated the same as the prior example.
8474 The expectation is that this might be used to implement a policy
8477 was handled by a central hub,
8480 was delivered directly.
8482 Version level three files
8483 allow # initiated comments on all lines.
8484 Exceptions are backslash escaped # marks
8487 Version level four configurations
8488 are completely equivalent to level three
8489 for historical reasons.
8491 Version level five configuration files
8492 change the default definition of
8494 to be just the first component of the hostname.
8496 Version level six configuration files
8497 change many of the local processing options
8498 (such as aliasing and matching the beginning of the address for
8501 this allows fine-grained control over the special local processing.
8502 Level six configuration files may also use long option names.
8505 option (to allow colons in the local-part of addresses)
8508 for lower numbered configuration files;
8509 the configuration file requires some additional intelligence
8510 to properly handle the RFC 822 group construct.
8512 Version level seven configuration files
8513 used new option names to replace old macros
8517 .b SmtpGreetingMessage ,
8525 Also, prior to version seven,
8528 flag (use 250 instead of 252 return value for
8533 Version level eight configuration files allow
8535 on the left hand side of ruleset lines.
8537 Version level nine configuration files allow
8538 parentheses in rulesets, i.e. they are not treated
8539 as comments and hence removed.
8541 Version level ten configuration files allow
8542 queue group definitions.
8546 line may have an optional
8549 to indicate that this configuration file uses modifications
8550 specific to a particular vendor\**.
8552 \**And of course, vendors are encouraged to add themselves
8553 to the list of recognized vendors by editing the routine
8557 Please send e-mail to sendmail@Sendmail.ORG
8558 to register your vendor dialect.
8562 to emphasize that this configuration file
8563 uses the Berkeley dialect of
8565 .sh 2 "K \*- Key File Declaration"
8567 Special maps can be defined using the line:
8569 Kmapname mapclass arguments
8573 is the handle by which this map is referenced in the rewriting rules.
8576 is the name of a type of map;
8577 these are compiled in to
8581 are interpreted depending on the class;
8583 there would be a single argument naming the file containing the map.
8585 Maps are referenced using the syntax:
8587 $( \fImap\fP \fIkey\fP $@ \fIarguments\fP $: \fIdefault\fP $)
8589 where either or both of the
8593 portion may be omitted.
8596 may appear more than once.
8601 are passed to the appropriate mapping function.
8602 If it returns a value, it replaces the input.
8603 If it does not return a value and the
8608 Otherwise, the input is unchanged.
8612 are passed to the map for arbitrary use.
8613 Most map classes can interpolate these arguments
8614 into their values using the syntax
8619 to indicate the corresponding
8623 indicates the database key.
8624 For example, the rule
8627 R$\- ! $+ $: $(uucp $1 $@ $2 $: $2 @ $1 . UUCP $)
8629 Looks up the UUCP name in a (user defined) UUCP map;
8630 if not found it turns it into
8633 The database might contain records like:
8635 decvax %1@%0.DEC.COM
8636 research %1@%0.ATT.COM
8640 clauses never do this mapping.
8642 The built-in map with both name and class
8644 is the host name canonicalization lookup.
8648 $(host \fIhostname\fP$)
8655 There are many defined classes.
8657 Database lookups using the ndbm(3) library.
8659 must be compiled with
8663 Database lookups using the btree interface to the Berkeley DB
8666 must be compiled with
8670 Database lookups using the hash interface to the Berkeley DB
8673 must be compiled with
8679 must be compiled with
8685 must be compiled with
8688 The argument is the name of the table to use for lookups,
8693 flags may be used to set the key and value columns respectively.
8697 must be compiled with
8701 LDAP X500 directory lookups.
8703 must be compiled with
8706 The map supports most of the standard arguments
8707 and most of the command line arguments of the
8712 if a single query matches multiple values,
8713 only the first value will be returned
8720 map flag will treat a multiple value return
8721 as if there were no matches.
8723 NeXT NetInfo lookups.
8725 must be compiled with
8730 The format of the text file is defined by the
8734 (value field number),
8741 Contributed and supported by
8742 Mark Roth, roth@uiuc.edu.
8743 For more information,
8744 consult the web site
8745 .q http://www-dev.cites.uiuc.edu/sendmail/ .
8747 nsd map for IRIX 6.5 and later.
8748 Contributed and supported by Bob Mende of SGI,
8751 Internal symbol table lookups.
8752 Used internally for aliasing.
8754 Really should be called
8756 \(em this is used to get the default lookups
8758 and is the default if no class is specified for alias files.
8760 Looks up users using
8764 flag can be used to specify the name of the field to return
8765 (although this is normally used only to check the existence
8768 Canonifies host domain names.
8769 Given a host name it calls the name server
8770 to find the canonical name for that host.
8772 Returns the best MX record for a host name given as the key.
8773 The current machine is always preferred \*-
8774 that is, if the current machine is one of the hosts listed as a
8775 lowest-preference MX record, then it will be guaranteed to be returned.
8776 This can be used to find out if this machine is the target for an MX record,
8777 and mail can be accepted on that basis.
8780 flag is given, then all MX names are returned,
8781 separated by the given delimiter.
8783 This map requires the option -R to specify the DNS resource record
8784 type to lookup. The following types are supported:
8785 A, AAAA, AFSDB, CNAME, MX, NS, PTR, SRV, and TXT.
8786 A map lookup will return only one record.
8787 Hence for some types, e.g., MX records, the return value might be a random
8788 element of the list due to randomizing in the DNS resolver.
8790 The arguments on the `K' line are a list of maps;
8791 the resulting map searches the argument maps in order
8792 until it finds a match for the indicated key.
8793 For example, if the key definition is:
8797 Kseqmap sequence map1 map2
8799 then a lookup against
8801 first does a lookup in map1.
8802 If that is found, it returns immediately.
8803 Otherwise, the same key is used for map2.
8805 the key is logged via
8807 The lookup returns the empty string.
8811 map except that the order of maps is determined by the service switch.
8812 The argument is the name of the service to be looked up;
8813 the values from the service switch are appended to the map name
8814 to create new map names.
8815 For example, consider the key definition:
8819 together with the service switch entry:
8823 This causes a query against the map
8825 to search maps named
8831 Strip double quotes (") from a name.
8832 It does not strip backslashes,
8833 and will not strip quotes if the resulting string
8834 would contain unscannable syntax
8835 (that is, basic errors like unbalanced angle brackets;
8836 more sophisticated errors such as unknown hosts are not checked).
8837 The intent is for use when trying to accept mail from systems such as
8839 that routinely quote odd syntax such as
8843 A typical usage is probably something like:
8849 R$\- $: $(dequote $1 $)
8850 R$\- $+ $: $>3 $1 $2
8852 Care must be taken to prevent unexpected results;
8855 "|someprogram < input > output"
8857 will have quotes stripped,
8858 but the result is probably not what you had in mind.
8859 Fortunately these cases are rare.
8861 The map definition on the
8863 line contains a regular expression.
8864 Any key input is compared to that expression using the
8865 POSIX regular expressions routines regcomp(), regerr(), and regexec().
8866 Refer to the documentation for those routines for more information
8867 about the regular expression matching.
8868 No rewriting of the key is done if the
8870 flag is used. Without it, the key is discarded or if
8872 if used, it is substituted by the substring matches, delimited by
8874 or the string specified with the the
8876 flag. The flags available for the map are
8881 -b basic regular expressions (default is extended)
8883 -d set the delimiter used for -s
8884 -a append string to key
8885 -m match only, do not replace/discard value
8886 -D perform no lookup in deferred delivery mode.
8890 flag can include an optional parameter which can be used
8891 to select the substrings in the result of the lookup. For example,
8900 If the pattern contains spaces, they must be replaced
8901 with the blank substitution character, unless it is
8904 The arguments on the
8906 line are the pathname to a program and any initial parameters to be passed.
8907 When the map is called,
8908 the key is added to the initial parameters
8909 and the program is invoked
8910 as the default user/group id.
8911 The first line of standard output is returned as the value of the lookup.
8912 This has many potential security problems,
8913 and has terrible performance;
8914 it should be used only when absolutely necessary.
8916 Set or clear a macro value.
8918 pass the value as the first argument in the map lookup.
8920 do not pass an argument in the map lookup.
8921 The map always returns the empty string.
8922 Example of typical usage include:
8928 # set macro ${MyMacro} to the ruleset match
8929 R$+ $: $(storage {MyMacro} $@ $1 $) $1
8930 # set macro ${MyMacro} to an empty string
8931 R$* $: $(storage {MyMacro} $@ $) $1
8932 # clear macro ${MyMacro}
8933 R$\- $: $(storage {MyMacro} $) $1
8936 Perform simple arithmetic operations.
8937 The operation is given as key, currently
8939 |, & (bitwise OR, AND),
8940 l (for less than), =,
8941 and r (for random) are supported.
8942 The two operands are given as arguments.
8943 The lookup returns the result of the computation,
8948 for comparisons, integer values otherwise.
8949 The r operator returns a pseudo-random number whose value
8950 lies between the first and second operand
8951 (which requires that the first operand is smaller than the second).
8952 All options which are possible for maps are ignored.
8953 A simple example is:
8960 R$* $: $(comp l $@ $&{load_avg} $@ 7 $) $1
8961 RFALSE $# error \&...
8964 The socket map uses a simple request/reply protocol over TCP or UNIX domain
8965 sockets to query an external server.
8966 Both requests and replies are text based and encoded as netstrings,
8967 i.e., a string "hello there" becomes:
8971 Note: neither requests nor replies end with CRLF.
8973 The request consists of the database map name and the lookup key separated
8974 by a space character:
8980 The server responds with a status indicator and the result (if any):
8983 <status> ' ' <result>
8986 The status indicator specifies the result of the lookup operation itself
8987 and is one of the following upper case words:
8990 OK the key was found, result contains the looked up value
8991 NOTFOUND the key was not found, the result is empty
8992 TEMP a temporary failure occured
8993 TIMEOUT a timeout occured on the server side
8994 PERM a permanent failure occured
8997 In case of errors (status TEMP, TIMEOUT or PERM) the result field may
8998 contain an explanatory message.
8999 However, the explanatory message is not used any further by
9004 31:OK resolved.address@example.com,
9008 56:OK error:550 5.7.1 User does not accept mail from sender,
9011 in case of successful lookups, or:
9016 in case the key was not found, or:
9018 55:TEMP this text explains that we had a temporary failure,
9021 in case of a temporary map lookup failure.
9023 The socket map uses the same syntax as milters
9024 (see Section "X \*- Mail Filter (Milter) Definitions")
9025 to specify the remote endpoint, e.g.,
9027 Ksocket mySocketMap inet:12345@127.0.0.1
9030 If multiple socket maps define the same remote endpoint, they will share
9031 a single connection to this endpoint.
9033 Most of these accept as arguments the same optional flags
9035 (or a mapname for NIS;
9036 the filename is the root of the database path,
9039 or some other extension appropriate for the database type
9040 will be added to get the actual database name).
9043 Indicates that this map is optional \*- that is,
9044 if it cannot be opened,
9045 no error is produced,
9048 will behave as if the map existed but was empty.
9056 uses an adaptive algorithm to decide whether or not to look for null bytes
9058 It starts by trying both;
9059 if it finds any key with a null byte it never tries again without a null byte
9063 is specified it never tries without a null byte and
9066 is specified it never tries with a null byte.
9068 these can speed matches but are never necessary.
9075 will never try any matches at all \(em
9076 that is, everything will appear to fail.
9080 on successful matches.
9081 For example, the default
9083 map appends a dot on successful matches.
9087 on temporary failures.
9090 would be appended if a DNS lookup returned
9092 or an NIS lookup could not locate a server.
9097 Do not fold upper to lower case before looking up the key.
9099 Match only (without replacing the value).
9100 If you only care about the existence of a key and not the value
9101 (as you might when searching the NIS map
9104 this flag prevents the map from substituting the value.
9106 The \-a argument is still appended on a match,
9107 and the default is still taken if the match fails.
9108 .ip "\-k\fIkeycol\fP"
9109 The key column name (for NIS+) or number
9111 For LDAP maps this is an LDAP filter string
9112 in which %s is replaced with the literal contents of the lookup key
9113 and %0 is replaced with the LDAP escaped contents of the lookup key
9114 according to RFC 2254.
9117 is used, then %1 through %9 are replaced with the LDAP escaped contents
9118 of the arguments specified in the map lookup.
9119 .ip "\-v\fIvalcol\fP"
9120 The value column name (for NIS+) or number
9122 For LDAP maps this is the name of one or more
9123 attributes to be returned;
9124 multiple attributes can be separated by commas.
9125 If not specified, all attributes found in the match
9127 The attributes listed can also include a type and one or more
9128 objectClass values for matching as described in the LDAP section.
9129 .ip "\-z\fIdelim\fP"
9130 The column delimiter (for text lookups).
9131 It can be a single character or one of the special strings
9135 to indicate newline or tab respectively.
9136 If omitted entirely,
9137 the column separator is any sequence of white space.
9138 For LDAP maps this is the separator character
9139 to combine multiple values
9140 into a single return string.
9142 the LDAP lookup will only return the first match found.
9143 For DNS maps this is the separator character at which
9144 the result of a query is cut off if is too long.
9146 Normally, when a map attempts to do a lookup
9147 and the server fails
9150 couldn't contact any name server;
9153 the same as an entry not being found in the map),
9154 the message being processed is queued for future processing.
9157 flag turns off this behavior,
9158 letting the temporary failure (server down)
9159 act as though it were a permanent failure (entry not found).
9160 It is particularly useful for DNS lookups,
9161 where someone else's misconfigured name server can cause problems
9163 However, care must be taken to ensure that you don't bounce mail
9164 that would be resolved correctly if you tried again.
9165 A common strategy is to forward such mail
9166 to another, possibly better connected, mail server.
9168 Perform no lookup in deferred delivery mode.
9169 This flag is set by default for the
9172 .ip "\-S\fIspacesub\fP
9173 The character to use to replace space characters
9174 after a successful map lookup (esp. useful for regex
9176 .ip "\-s\fIspacesub\fP
9177 For the dequote map only,
9178 the character to use to replace space characters
9179 after a successful dequote.
9181 Don't dequote the key before lookup.
9183 For the syslog map only, it specifies the level
9184 to use for the syslog call.
9186 When rebuilding an alias file,
9189 flag causes duplicate entries in the text version
9191 For example, two entries:
9196 would be treated as though it were the single entry
9198 list: user1, user2, user3
9200 in the presence of the
9204 Some additional flags are available for the host and dns maps:
9206 delay: specify the resolver's retransmission time interval (in seconds).
9208 retry: specify the number of times to retransmit a resolver query.
9210 The dns map has another flag:
9212 basedomain: specify a domain that is always appended to queries.
9214 The following additional flags are present in the ldap map only:
9216 Do not auto chase referrals. sendmail must be compiled with
9217 .b \-DLDAP_REFERRALS
9220 Retrieve attribute names only.
9222 Retrieve both attributes name and value(s),
9225 .ip "\-r\fIderef\fP"
9226 Set the alias dereference option to one of never, always, search, or find.
9227 .ip "\-s\fIscope\fP"
9228 Set search scope to one of base, one (one level), or sub (subtree).
9230 LDAP server hostname.
9231 Some LDAP libraries allow you to specify multiple, space-separated hosts for
9233 In addition, each of the hosts listed can be followed by a colon and a port
9234 number to override the default LDAP port.
9237 .ip "\-H \fILDAPURI\fP"
9238 Use the specified LDAP URI instead of specifying the hostname and port
9239 separately with the the
9243 options shown above.
9246 -h server.example.com -p 389 -b dc=example,dc=com
9250 -H ldap://server.example.com:389 -b dc=example,dc=com
9252 If the LDAP library supports it,
9253 the LDAP URI format however can also request LDAP over SSL by using
9259 O LDAPDefaultSpec=-H ldaps://ldap.example.com -b dc=example,dc=com
9261 Similarly, if the LDAP library supports it,
9262 It can also be used to specify a UNIX domain socket using
9265 O LDAPDefaultSpec=-H ldapi://socketfile -b dc=example,dc=com
9269 .ip "\-l\fItimelimit\fP"
9270 Time limit for LDAP queries.
9271 .ip "\-Z\fIsizelimit\fP"
9272 Size (number of matches) limit for LDAP or DNS queries.
9273 .ip "\-d\fIdistinguished_name\fP"
9274 The distinguished name to use to login to the LDAP server.
9275 .ip "\-M\fImethod\fP"
9276 The method to authenticate to the LDAP server.
9279 .b LDAP_AUTH_SIMPLE ,
9281 .b LDAP_AUTH_KRBV4 .
9282 .ip "\-P\fIpasswordfile\fP"
9283 The file containing the secret key for the
9285 authentication method
9286 or the name of the Kerberos ticket file for
9287 .b LDAP_AUTH_KRBV4 .
9289 Force LDAP searches to only succeed if a single match is found.
9290 If multiple values are found,
9291 the search is treated as if no match was found.
9292 .ip "\-w\fIversion\fP"
9293 Set the LDAP API/protocol version to use.
9294 The default depends on the LDAP client libraries in use.
9299 to use LDAPv3 when communicating with the LDAP server.
9301 Treat the LDAP search key as multi-argument and
9302 replace %1 through %9 in the key with
9303 the LDAP escaped contents of the lookup arguments specified in the map lookup.
9307 map appends the strings
9311 to the given filename;
9318 For example, the map specification
9320 Kuucp dbm \-o \-N /etc/mail/uucpmap
9322 specifies an optional map named
9326 it always has null bytes at the end of every string,
9327 and the data is located in
9328 /etc/mail/uucpmap.{dir,pag}.
9332 can be used to build any of the three database-oriented maps.
9333 It takes the following flags:
9335 Do not fold upper to lower case in the map.
9337 Include null bytes in keys.
9339 Append to an existing (old) file.
9341 Allow replacement of existing keys;
9342 normally, re-inserting an existing key is an error.
9344 Print what is happening.
9348 daemon does not have to be restarted to read the new maps
9349 as long as you change them in place;
9350 file locking is used so that the maps won't be read
9351 while they are being updated.
9353 New classes can be added in the routine
9357 .sh 2 "Q \*- Queue Group Declaration"
9359 In addition to the option
9361 queue groups can be declared that define a (group of) queue directories
9362 under a common name.
9363 The syntax is as follows:
9373 is the symbolic name of the queue group under which
9374 it can be referenced in various places
9377 pairs define attributes of the queue group.
9378 The name must only consist of alphanumeric characters.
9381 Flags for this queue group.
9383 The nice(2) increment for the queue group.
9384 This value must be greater or equal zero.
9386 The time between two queue runs.
9388 The queue directory of the group (required).
9390 The number of parallel runners processing the queue.
9393 must be set if this value is greater than one.
9395 The maximum number of jobs (messages delivered) per queue run.
9397 The maximum number of recipients per envelope.
9398 Envelopes with more than this number of recipients will be split
9399 into multiple envelopes in the same queue directory.
9400 The default value 0 means no limit.
9402 Only the first character of the field name is checked.
9404 By default, a queue group named
9406 is defined that uses the value of the
9409 Notice: all paths that are used for queue groups must
9410 be subdirectories of
9412 Since they can be symbolic links, this isn't a real restriction,
9415 uses a wildcard, then the directory one level up is considered
9416 the ``base'' directory which all other queue directories must share.
9417 Please make sure that the queue directories do not overlap,
9418 e.g., do not specify
9420 O QueueDirectory=/var/spool/mqueue/*
9421 Qone, P=/var/spool/mqueue/dir1
9422 Qtwo, P=/var/spool/mqueue/dir2
9424 because this also includes
9428 in the default queue group.
9431 O QueueDirectory=/var/spool/mqueue/main*
9432 Qone, P=/var/spool/mqueue/dir
9433 Qtwo, P=/var/spool/mqueue/other*
9435 is a valid queue group specification.
9437 Options listed in the ``Flags'' field can be used to modify
9438 the behavior of a queue group.
9439 The ``f'' flag must be set if multiple queue runners are
9440 supposed to work on the entries in a queue group.
9443 will work on the entries strictly sequentially.
9445 The ``Interval'' field sets the time between queue runs.
9446 If no queue group specific interval is set, then the parameter of the
9448 option from the command line is used.
9450 To control the overall number of concurrently active queue runners
9454 This limits the number of processes used for running the queues to
9455 .b MaxQueueChildren ,
9456 though at any one time fewer processes may be active
9457 as a result of queue options, completed queue runs, system load, etc.
9459 The maximum number of queue runners for an individual queue group can be
9463 If set to 0, entries in the queue will not be processed, which
9464 is useful to ``quarantine'' queue files.
9465 The number of runners per queue group may also be set with the option
9466 .b MaxRunnersPerQueue ,
9467 which applies to queue groups that have no individual limit.
9468 That is, the default value for
9471 .b MaxRunnersPerQueue
9472 if set, otherwise 1.
9474 The field Jobs describes the maximum number of jobs
9475 (messages delivered) per queue run, which is the queue group specific
9477 .b MaxQueueRunSize .
9479 Notice: queue groups should be declared after all queue related options
9480 have been set because queue groups take their defaults from those options.
9481 If an option is set after a queue group declaration, the values of
9482 options in the queue group are set to the defaults of
9484 unless explicitly set in the declaration.
9486 Each envelope is assigned to a queue group based on the algorithm
9487 described in section
9488 ``Queue Groups and Queue Directories''.
9489 .sh 2 "X \*- Mail Filter (Milter) Definitions"
9493 Mail Filter API (Milter) is designed to allow third-party programs access
9494 to mail messages as they are being processed in order to filter
9495 meta-information and content.
9496 They are declared in the configuration file as:
9506 is the name of the filter
9507 (used internally only)
9510 pairs define attributes of the filter.
9511 Also see the documentation for the
9513 option for more information.
9518 Socket The socket specification
9519 Flags Special flags for this filter
9520 Timeouts Timeouts for this filter
9522 Only the first character of the field name is checked
9523 (it's case-sensitive).
9525 The socket specification is one of the following forms:
9548 The first two describe an IPv4 or IPv6 socket listening on a certain
9553 The final form describes a named socket on the filesystem at the given
9556 The following flags may be set in the filter description.
9559 Reject connection if filter unavailable.
9561 Temporary fail connection if filter unavailable.
9563 If neither F=R nor F=T is specified, the message is passed through
9565 in case of filter errors as if the failing filters were not present.
9567 The timeouts can be set using the four fields inside of the
9572 Timeout for connecting to a filter.
9573 If set to 0, the system's
9575 timeout will be used.
9577 Timeout for sending information from the MTA to a filter.
9579 Timeout for reading reply from the filter.
9581 Overall timeout between sending end-of-message to filter and waiting for
9582 the final acknowledgment.
9584 Note the separator between each timeout field is a
9586 The default values (if not set) are:
9587 .b T=C:5m;S:10s;R:10s;E:5m
9596 Xfilter1, S=local:/var/run/f1.sock, F=R
9597 Xfilter2, S=inet6:999@localhost, F=T, T=S:1s;R:1s;E:5m
9598 Xfilter3, S=inet:3333@localhost, T=C:2m
9600 .sh 2 "The User Database"
9602 The user database is deprecated in favor of ``virtusertable''
9603 and ``genericstable'' as explained in the file
9605 If you have a version of
9607 with the user database package
9609 the handling of sender and recipient addresses
9612 The location of this database is controlled with the
9615 .sh 3 "Structure of the user database"
9617 The database is a sorted (BTree-based) structure.
9618 User records are stored with the key:
9620 \fIuser-name\fP\fB:\fP\fIfield-name\fP
9622 The sorted database format ensures that user records are clustered together.
9623 Meta-information is always stored with a leading colon.
9625 Field names define both the syntax and semantics of the value.
9626 Defined fields include:
9629 The delivery address for this user.
9630 There may be multiple values of this record.
9632 mailing lists will have one
9634 record for each user on the list.
9636 The outgoing mailname for this user.
9637 For each outgoing name,
9638 there should be an appropriate
9640 record for that name to allow return mail.
9642 .i :default:mailname .
9644 Changes any mail sent to this address to have the indicated envelope sender.
9645 This is intended for mailing lists,
9646 and will normally be the name of an appropriate -request address.
9647 It is very similar to the owner-\c
9649 syntax in the alias file.
9651 The full name of the user.
9653 The office address for this user.
9655 The office phone number for this user.
9657 The office FAX number for this user.
9659 The home address for this user.
9661 The home phone number for this user.
9663 The home FAX number for this user.
9665 A (short) description of the project this person is affiliated with.
9666 In the University this is often just the name of their graduate advisor.
9668 A pointer to a file from which plan information can be gathered.
9671 only a few of these fields are actually being used by
9678 program that uses the other fields is planned.
9679 .sh 3 "User database semantics"
9681 When the rewriting rules submit an address to the local mailer,
9682 the user name is passed through the alias file.
9683 If no alias is found (or if the alias points back to the same address),
9687 is then used as a key in the user database.
9688 If no match occurs (or if the maildrop points at the same address),
9689 forwarding is tried.
9691 If the first token of the user name returned by ruleset 0
9694 sign, the user database lookup is skipped.
9695 The intent is that the user database will act as a set of defaults
9696 for a cluster (in our case, the Computer Science Division);
9697 mail sent to a specific machine should ignore these defaults.
9700 the name of the sending user is looked up in the database.
9704 the value of that record is used as their outgoing name.
9705 For example, I might have a record:
9707 eric:mailname Eric.Allman@CS.Berkeley.EDU
9709 This would cause my outgoing mail to be sent as Eric.Allman.
9713 is found for the user,
9714 but no corresponding
9718 .q :default:mailname
9720 If present, this is the name of a host to override the local host.
9721 For example, in our case we would set it to
9722 .q CS.Berkeley.EDU .
9723 The effect is that anyone known in the database
9724 gets their outgoing mail stamped as
9725 .q user@CS.Berkeley.EDU ,
9726 but people not listed in the database use the local hostname.
9727 .sh 3 "Creating the database\**"
9729 \**These instructions are known to be incomplete.
9730 Other features are available which provide similar functionality,
9731 e.g., virtual hosting and mapping local addresses into a
9732 generic form as explained in cf/README.
9735 The user database is built from a text file
9739 (in the distribution in the makemap subdirectory).
9740 The text file is a series of lines corresponding to userdb records;
9741 each line has a key and a value separated by white space.
9742 The key is always in the format described above \*-
9747 This file is normally installed in a system directory;
9748 for example, it might be called
9749 .i /etc/mail/userdb .
9750 To make the database version of the map, run the program:
9752 makemap btree /etc/mail/userdb < /etc/mail/userdb
9754 Then create a config file that uses this.
9755 For example, using the V8 M4 configuration, include the
9756 following line in your .mc file:
9758 define(\`confUSERDB_SPEC\', /etc/mail/userdb)
9760 .sh 1 "OTHER CONFIGURATION"
9762 There are some configuration changes that can be made by
9765 This section describes what changes can be made
9766 and what has to be modified to make them.
9767 In most cases this should be unnecessary
9768 unless you are porting
9770 to a new environment.
9771 .sh 2 "Parameters in devtools/OS/$oscf"
9773 These parameters are intended to describe the compilation environment,
9775 and should normally be defined in the operating system
9777 .b "This section needs a complete rewrite."
9780 the new version of the DBM library
9781 that allows multiple databases will be used.
9782 If neither NDBM nor NEWDB are set,
9783 a much less efficient method of alias lookup is used.
9785 If set, use the new database package from Berkeley (from 4.4BSD).
9786 This package is substantially faster than DBM or NDBM.
9787 If NEWDB and NDBM are both set,
9789 will read DBM files,
9790 but will create and use NEWDB files.
9792 Include support for NIS.
9793 If set together with
9797 will create both DBM and NEWDB files if and only if
9798 an alias file includes the substring
9801 This is intended for compatibility with Sun Microsystems'
9803 program used on YP masters.
9805 Compile in support for NIS+.
9807 Compile in support for NetInfo (NeXT stations).
9809 Compile in support for LDAP X500 queries.
9810 Requires libldap and liblber
9811 from the Umich LDAP 3.2 or 3.3 release
9812 or equivalent libraries for other LDAP libraries
9815 Compile in support for Hesiod.
9817 Compile in support for IRIX NSD lookups.
9819 Compile in support for regular expression matching.
9821 Compile in support for DNS map lookups in the
9825 Compile in support for ph lookups.
9827 Compile in support for SASL,
9828 a required component for SMTP Authentication support.
9830 Compile in support for STARTTLS.
9832 Compile in support for the "Entropy Gathering Daemon"
9833 to provide better random data for TLS.
9835 Compile in support for TCP Wrappers.
9836 .ip _PATH_SENDMAILCF
9837 The pathname of the sendmail.cf file.
9838 .ip _PATH_SENDMAILPID
9839 The pathname of the sendmail.pid file.
9841 Compile in support for shared memory, see section about
9842 "/var/spool/mqueue".
9844 Compile in support for contacting external mail filters built with the
9847 There are also several compilation flags to indicate the environment
9852 See the sendmail/README
9853 file for the latest scoop on these flags.
9854 .sh 2 "Parameters in sendmail/conf.h"
9856 Parameters and compilation options
9857 are defined in conf.h.
9858 Most of these need not normally be tweaked;
9859 common parameters are all in sendmail.cf.
9860 However, the sizes of certain primitive vectors, etc.,
9861 are included in this file.
9862 The numbers following the parameters
9863 are their default value.
9865 This document is not the best source of information
9866 for compilation flags in conf.h \(em
9867 see sendmail/README or sendmail/conf.h itself.
9869 .ip "MAXLINE [2048]"
9870 The maximum line length of any input line.
9871 If message lines exceed this length
9872 they will still be processed correctly;
9873 however, header lines,
9874 configuration file lines,
9877 must fit within this limit.
9879 The maximum length of any name,
9880 such as a host or a user name.
9882 The maximum number of parameters to any mailer.
9883 This limits the number of recipients that may be passed in one transaction.
9884 It can be set to any arbitrary number above about 10,
9887 will break up a delivery into smaller batches as needed.
9888 A higher number may reduce load on your system, however.
9889 .ip "MAXQUEUEGROUPS [50]"
9890 The maximum number of queue groups.
9891 .ip "MAXATOM [1000]"
9892 The maximum number of atoms
9894 in a single address.
9897 .q "eric@CS.Berkeley.EDU"
9899 .ip "MAXMAILERS [25]"
9900 The maximum number of mailers that may be defined
9901 in the configuration file.
9902 This value is defined in include/sendmail/sendmail.h.
9903 .ip "MAXRWSETS [200]"
9904 The maximum number of rewriting sets
9905 that may be defined.
9906 The first half of these are reserved for numeric specification
9908 while the upper half are reserved for auto-numbering
9910 Thus, with a value of 200 an attempt to use ``S99'' will succeed,
9911 but ``S100'' will fail.
9912 .ip "MAXPRIORITIES [25]"
9913 The maximum number of values for the
9915 field that may be defined
9918 line in sendmail.cf).
9919 .ip "MAXUSERENVIRON [100]"
9920 The maximum number of items in the user environment
9921 that will be passed to subordinate mailers.
9922 .ip "MAXMXHOSTS [100]"
9923 The maximum number of MX records we will accept for any single host.
9924 .ip "MAXMAPSTACK [12]"
9925 The maximum number of maps that may be "stacked" in a
9928 .ip "MAXMIMEARGS [20]"
9929 The maximum number of arguments in a MIME Content-Type: header;
9930 additional arguments will be ignored.
9931 .ip "MAXMIMENESTING [20]"
9932 The maximum depth to which MIME messages may be nested
9933 (that is, nested Message or Multipart documents;
9934 this does not limit the number of components in a single Multipart document).
9935 .ip "MAXDAEMONS [10]"
9936 The maximum number of sockets sendmail will open for accepting connections
9938 .ip "MAXMACNAMELEN [25]"
9939 The maximum length of a macro name.
9941 A number of other compilation options exist.
9942 These specify whether or not specific code should be compiled in.
9943 Ones marked with \(dg
9948 support for Internet protocol networking is compiled in.
9949 Previous versions of
9953 this old usage is now incorrect.
9955 turn it off in the Makefile
9956 if your system doesn't support the Internet protocols.
9959 support for IPv6 networking is compiled in.
9960 It must be separately enabled by adding
9961 .b DaemonPortOptions
9965 support for ISO protocol networking is compiled in
9966 (it may be appropriate to #define this in the Makefile instead of conf.h).
9969 support for UNIX domain sockets is compiled in.
9970 This is used for control socket support.
9975 routine in use at some sites is used.
9976 This makes an informational log record
9977 for each message processed,
9978 and makes a higher priority log record
9979 for internal system errors.
9980 .b "STRONGLY RECOMMENDED"
9981 \(em if you want no logging, turn it off in the configuration file.
9983 Compile in the code to do ``fuzzy matching'' on the GECOS field
9985 This also requires that the
9987 option be turned on.
9989 Compile in code to use the
9990 Berkeley Internet Name Domain (BIND) server
9991 to resolve TCP/IP host names.
9993 If you are using a non-UNIX mail format,
9994 you can set this flag to turn off special processing
10001 Berkeley user information database package.
10002 This adds a new level of local name expansion
10003 between aliasing and forwarding.
10004 It also uses the NEWDB package.
10005 This may change in future releases.
10007 The following options are normally turned on
10008 in per-operating-system clauses in conf.h.
10010 Compile in the IDENT protocol as defined in RFC 1413.
10011 This defaults on for all systems except Ultrix,
10012 which apparently has the interesting
10014 that when it receives a
10015 .q "host unreachable"
10016 message it closes all open connections to that host.
10017 Since some firewall gateways send this error code
10018 when you access an unauthorized port (such as 113, used by IDENT),
10019 Ultrix cannot receive email from such hosts.
10021 Set all of the compilation parameters appropriate for System V.
10025 instead of System V
10027 to do file locking.
10028 Due to the highly unusual semantics of locks
10031 this should always be used if at all possible.
10033 Set this if your system has the
10036 (if you have multiple group support).
10037 This is the default if SYSTEM5 is
10039 defined or if you are on HPUX.
10041 Set this if you have the
10043 system call (or corresponding library routine).
10047 .ip HASGETDTABLESIZE
10048 Set this if you have the
10049 .i getdtablesize (2)
10052 Set this if you have the
10055 .ip FAST_PID_RECYCLE
10056 Set this if your system can possibly
10057 reuse the same pid in the same second of time.
10059 The mechanism that can be used to get file system capacity information.
10060 The values can be one of
10061 SFS_USTAT (use the ustat(2) syscall),
10062 SFS_4ARGS (use the four argument statfs(2) syscall),
10063 SFS_VFS (use the two argument statfs(2) syscall including <sys/vfs.h>),
10064 SFS_MOUNT (use the two argument statfs(2) syscall including <sys/mount.h>),
10065 SFS_STATFS (use the two argument statfs(2) syscall including <sys/statfs.h>),
10066 SFS_STATVFS (use the two argument statfs(2) syscall including <sys/statvfs.h>),
10068 SFS_NONE (no way to get this information).
10070 The load average type.
10071 Details are described below.
10073 The are several built-in ways of computing the load average.
10075 tries to auto-configure them based on imperfect guesses;
10076 you can select one using the
10085 The kernel stores the load average in the kernel as an array of long integers.
10086 The actual values are scaled by a factor FSCALE
10089 The kernel stores the load average in the kernel as an array of short integers.
10090 The actual values are scaled by a factor FSCALE
10093 The kernel stores the load average in the kernel as an array of
10094 double precision floats.
10096 Use MACH-style load averages.
10100 routine to get the load average as an array of doubles.
10102 Always return zero as the load average.
10103 This is the fallback case.
10111 you may also need to specify
10113 (the path to your system binary)
10116 (the name of the variable containing the load average in the kernel;
10121 .sh 2 "Configuration in sendmail/conf.c"
10123 The following changes can be made in conf.c.
10124 .sh 3 "Built-in Header Semantics"
10126 Not all header semantics are defined in the configuration file.
10127 Header lines that should only be included by certain mailers
10128 (as well as other more obscure semantics)
10129 must be specified in the
10133 This table contains the header name
10134 (which should be in all lower case)
10135 and a set of header control flags (described below),
10138 Normally when the check is made to see if a header line is compatible
10141 will not delete an existing line.
10142 If this flag is set,
10145 even existing header lines.
10147 if this bit is set and the mailer does not have flag bits set
10148 that intersect with the required mailer flags
10149 in the header definition in
10155 If this header field is set,
10156 treat it like a blank line,
10158 it will signal the end of the header
10159 and the beginning of the message text.
10161 Add this header entry
10162 even if one existed in the message before.
10163 If a header entry does not have this bit set,
10165 will not add another header line if a header line
10166 of this name already existed.
10167 This would normally be used to stamp the message
10168 by everyone who handled it.
10171 this is a timestamp
10174 If the number of trace fields in a message
10175 exceeds a preset amount
10176 the message is returned
10177 on the assumption that it has an aliasing loop.
10180 this field contains recipient addresses.
10181 This is used by the
10183 flag to determine who to send to
10184 when it is collecting recipients from the message.
10186 This flag indicates that this field
10187 specifies a sender.
10188 The order of these fields in the
10193 for which field to return error messages to.
10195 Addresses in this header should receive error messages.
10197 This header is a Content-Transfer-Encoding header.
10199 This header is a Content-Type header.
10201 Strip the value from the header (for Bcc:).
10204 Let's look at a sample
10208 .ta 4n +\w'"content-transfer-encoding", 'u
10209 struct hdrinfo HdrInfo[] =
10211 /* originator fields, most to least significant */
10212 "resent-sender", H_FROM,
10213 "resent-from", H_FROM,
10216 "full-name", H_ACHECK,
10217 "errors-to", H_FROM\^|\^H_ERRORSTO,
10218 /* destination fields */
10220 "resent-to", H_RCPT,
10222 "bcc", H_RCPT\^|\^H_STRIPVAL,
10223 /* message identification and control */
10227 "received", H_TRACE\^|\^H_FORCE,
10228 /* miscellaneous fields */
10229 "content-transfer-encoding", H_CTE,
10230 "content-type", H_CTYPE,
10235 This structure indicates that the
10241 all specify recipient addresses.
10244 field will be deleted unless the required mailer flag
10245 (indicated in the configuration file)
10251 fields will terminate the header;
10252 these are used by random dissenters around the network world.
10255 field will always be added,
10256 and can be used to trace messages.
10258 There are a number of important points here.
10260 header fields are not added automatically just because they are in the
10263 they must be specified in the configuration file
10264 in order to be added to the message.
10265 Any header fields mentioned in the configuration file but not
10268 structure have default processing performed;
10270 they are added unless they were in the message already.
10274 structure only specifies cliched processing;
10275 certain headers are processed specially by ad hoc code
10276 regardless of the status specified in
10283 fields are always scanned on ARPANET mail
10284 to determine the sender\**;
10286 \**Actually, this is no longer true in SMTP;
10287 this information is contained in the envelope.
10288 The older ARPANET protocols did not completely distinguish
10289 envelope from header.
10291 this is used to perform the
10292 .q "return to sender"
10298 fields are used to determine the full name of the sender
10300 this is stored in the macro
10302 and used in a number of ways.
10303 .sh 3 "Restricting Use of Email"
10305 If it is necessary to restrict mail through a relay,
10308 routine can be modified.
10309 This routine is called for every recipient address.
10310 It returns an exit status
10311 indicating the status of the message.
10314 accepts the address,
10316 queues the message for a later try,
10319 .sm EX_UNAVAILABLE )
10320 reject the message.
10323 to print an error message
10326 if the message is rejected.
10333 .ta 4n +4n +4n +4n +4n +4n +4n
10336 register ADDRESS *to;
10337 register ENVELOPE *e;
10341 s = stab("private", ST_MAILER, ST_FIND);
10342 if (s != NULL && e\->e_from.q_mailer != LocalMailer &&
10343 to->q_mailer == s->s_mailer)
10345 usrerr("No private net mail allowed through this machine");
10346 return (EX_UNAVAILABLE);
10348 if (MsgSize > 50000 && bitnset(M_LOCALMAILER, to\->q_mailer))
10350 usrerr("Message too large for non-local delivery");
10351 e\->e_flags |= EF_NORETURN;
10352 return (EX_UNAVAILABLE);
10358 This would reject messages greater than 50000 bytes
10359 unless they were local.
10364 to suppress the return of the actual body
10365 of the message in the error return.
10366 The actual use of this routine is highly dependent on the
10368 and use should be limited.
10369 .sh 3 "New Database Map Classes"
10371 New key maps can be added by creating a class initialization function
10372 and a lookup function.
10373 These are then added to the routine
10376 The initialization function is called as
10378 \fIxxx\fP_map_init(MAP *map, char *args)
10382 is an internal data structure.
10385 is a pointer to the portion of the configuration file line
10386 following the map class name;
10387 flags and filenames can be extracted from this line.
10388 The initialization function must return
10390 if it successfully opened the map,
10394 The lookup function is called as
10396 \fIxxx\fP_map_lookup(MAP *map, char buf[], char **av, int *statp)
10400 defines the map internally.
10404 This may be (and often is) used destructively.
10407 is a list of arguments passed in from the rewrite line.
10408 The lookup function should return a pointer to the new value.
10409 If the map lookup fails,
10411 should be set to an exit status code;
10412 in particular, it should be set to
10414 if recovery is to be attempted by the higher level code.
10415 .sh 3 "Queueing Function"
10419 is called to decide if a message should be queued
10420 or processed immediately.
10421 Typically this compares the message priority to the current load average.
10422 The default definition is:
10425 shouldqueue(pri, ctime)
10429 if (CurrentLA < QueueLA)
10431 return (pri > (QueueFactor / (CurrentLA \- QueueLA + 1)));
10434 If the current load average
10437 which is set before this function is called)
10438 is less than the low threshold load average
10447 (that is, it should
10450 If the current load average exceeds the high threshold load average
10459 Otherwise, it computes the function based on the message priority,
10465 and the current and threshold load averages.
10467 An implementation wishing to take the actual age of the message into account
10471 which is the time that the message was first submitted to
10475 parameter is already weighted
10476 by the number of times the message has been tried
10477 (although this tends to lower the priority of the message with time);
10478 the expectation is that the
10480 would be used as an
10482 to ensure that messages are eventually processed.
10483 .sh 3 "Refusing Incoming SMTP Connections"
10486 .i refuseconnections
10489 if incoming SMTP connections should be refused.
10490 The current implementation is based exclusively on the current load average
10491 and the refuse load average option
10498 refuseconnections()
10500 return (RefuseLA > 0 && CurrentLA >= RefuseLA);
10503 A more clever implementation
10504 could look at more system resources.
10505 .sh 3 "Load Average Computation"
10509 returns the current load average (as a rounded integer).
10510 The distribution includes several possible implementations.
10511 If you are porting to a new environment
10512 you may need to add some new tweaks.\**
10514 \**If you do, please send updates to
10515 sendmail@Sendmail.ORG.
10517 .sh 2 "Configuration in sendmail/daemon.c"
10520 .i sendmail/daemon.c
10521 contains a number of routines that are dependent
10522 on the local networking environment.
10523 The version supplied assumes you have BSD style sockets.
10525 In previous releases,
10526 we recommended that you modify the routine
10528 if you wanted to generalize
10533 We now recommend that you create a new keyed map instead.
10536 In this section we assume that
10538 has been compiled with support for LDAP.
10539 .sh 3 "LDAP Recursion"
10541 LDAP Recursion allows you to add types to the search attributes on an
10542 LDAP map specification.
10544 .ip "\-v \fIATTRIBUTE\fP[:\fITYPE\fP[:\fIOBJECTCLASS\fP[|\fIOBJECTCLASS\fP|...]]]
10546 The new \fITYPE\fPs are:
10549 This attribute type specifies the attribute to add to the results string.
10550 This is the default.
10552 Any matches for this attribute are expected to have a value of a
10553 fully qualified distinguished name.
10555 will lookup that DN and apply the attributes requested to the
10556 returned DN record.
10558 Any matches for this attribute are expected to have a value of an
10559 LDAP search filter.
10561 will perform a lookup with the same parameters as the original
10562 search but replaces the search filter with the one specified here.
10564 Any matches for this attribute are expected to have a value of an LDAP URL.
10566 will perform a lookup of that URL and use the results from the attributes
10568 Note however that the search is done using the current LDAP connection,
10569 regardless of what is specified as the scheme, LDAP host, and LDAP
10570 port in the LDAP URL.
10572 Any untyped attributes are considered
10574 attributes as described above.
10576 The optional \fIOBJECTCLASS\fP (| separated) list contains the
10577 objectClass values for which that attribute applies.
10578 If the list is given,
10579 the attribute named will only be used if the LDAP record being returned is a
10580 member of that object class.
10581 Note that if these new value attribute \fITYPE\fPs are used in an
10583 option setting, it will need to be double quoted to prevent
10585 from misparsing the colons.
10587 Note that LDAP recursion attributes which do not ultimately point to an
10588 LDAP record are not considered an error.
10591 Since examples usually help clarify, here is an example which uses all
10592 four of the new types:
10594 O LDAPDefaultSpec=-h ldap.example.com -b dc=example,dc=com
10598 -k (&(objectClass=sendmailMTAAliasObject)(sendmailMTAKey=%0))
10599 -v sendmailMTAAliasValue,mail:NORMAL:inetOrgPerson,
10600 uniqueMember:DN:groupOfUniqueNames,
10601 sendmailMTAAliasSearch:FILTER:sendmailMTAAliasObject,
10602 sendmailMTAAliasURL:URL:sendmailMTAAliasObject
10605 That definition specifies that:
10608 .sm sendmailMTAAliasValue
10609 attribute will be added to the result string regardless of object class.
10613 attribute will be added to the result string if
10614 the LDAP record is a member of the
10620 attribute is a recursive attribute, used only in
10621 .sm groupOfUniqueNames
10622 records, and should contain an LDAP DN pointing to another LDAP record.
10623 The desire here is to return the
10625 attribute from those DNs.
10628 .sm sendmailMTAAliasSearch
10630 .sm sendmailMTAAliasURL
10631 are both used only if referenced in a
10632 .sm sendmailMTAAliasObject .
10633 They are both recursive, the first for a new LDAP search string and the
10634 latter for an LDAP URL.
10637 In this section we assume that
10639 has been compiled with support for STARTTLS.
10640 To properly understand the use of STARTTLS in
10642 it is necessary to understand at least some basics about X.509 certificates
10643 and public key cryptography.
10644 This information can be found in books about SSL/TLS
10645 or on WWW sites, e.g.,
10646 .q http://www.OpenSSL.org/ .
10647 .sh 3 "Certificates for STARTTLS"
10649 When acting as a server,
10651 requires X.509 certificates to support STARTTLS:
10652 one as certificate for the server (ServerCertFile and corresponding
10653 private ServerKeyFile)
10654 at least one root CA (CACertFile),
10655 i.e., a certificate that is used to sign other certificates,
10656 and a path to a directory which contains other CAs (CACertPath).
10657 The file specified via
10659 can contain several certificates of CAs.
10660 The DNs of these certificates are sent
10661 to the client during the TLS handshake (as part of the
10662 CertificateRequest) as the list of acceptable CAs.
10663 However, do not list too many root CAs in that file, otherwise
10664 the TLS handshake may fail; e.g.,
10666 error:14094417:SSL routines:SSL3_READ_BYTES:
10667 sslv3 alert illegal parameter:s3_pkt.c:964:SSL alert number 47
10669 You should probably put only the CA cert into that file
10670 that signed your own cert(s), or at least only those you trust.
10671 The CACertPath directory must contain the hashes of each CA certificate
10672 as filenames (or as links to them).
10673 Symbolic links can be generated with the following
10674 two (Bourne) shell commands:
10676 C=FileName_of_CA_Certificate
10677 ln -s $C `openssl x509 -noout -hash < $C`.0
10679 A better way to do this is to use the
10681 command that is part of the OpenSSL distribution
10682 because it handles subject hash collisions
10683 by incrementing the number in the suffix of the filename of the symbolic link,
10689 An X.509 certificate is also required for authentication in client mode
10690 (ClientCertFile and corresponding private ClientKeyFile), however,
10692 will always use STARTTLS when offered by a server.
10693 The client and server certificates can be identical.
10694 Certificates can be obtained from a certificate authority
10695 or created with the help of OpenSSL.
10696 The required format for certificates and private keys is PEM.
10697 To allow for automatic startup of sendmail, private keys
10698 (ServerKeyFile, ClientKeyFile)
10699 must be stored unencrypted.
10700 The keys are only protected by the permissions of the file system.
10701 Never make a private key available to a third party.
10702 .sh 3 "PRNG for STARTTLS"
10704 STARTTLS requires a strong pseudo random number generator (PRNG)
10705 to operate properly.
10706 Depending on the TLS library you use, it may be required to explicitly
10707 initialize the PRNG with random data.
10708 OpenSSL makes use of
10710 if available (this corresponds to the compile flag HASURANDOMDEV).
10711 On systems which lack this support, a random file must be specified in the
10713 file using the option RandFile.
10716 advised to use the "Entropy Gathering Daemon" EGD
10717 from Brian Warner on those systems to provide useful random data.
10720 must be compiled with the flag EGD, and the
10721 RandFile option must point to the EGD socket.
10724 nor EGD are available, you have to make sure
10725 that useful random data is available all the time in RandFile.
10726 If the file hasn't been modified in the last 10 minutes before
10727 it is supposed to be used by
10729 the content is considered obsolete.
10730 One method for generating this file is:
10732 openssl rand -out /etc/mail/randfile -rand \c
10733 .i /path/to/file:... \c
10736 See the OpenSSL documentation for more information.
10737 In this case, the PRNG for TLS is only
10738 seeded with other random data if the
10739 .b DontBlameSendmail
10741 .b InsufficientEntropy
10743 This is most likely not sufficient for certain actions, e.g.,
10744 generation of (temporary) keys.
10746 Please see the OpenSSL documentation or other sources
10747 for further information about certificates, their creation and their usage,
10748 the importance of a good PRNG, and other aspects of TLS.
10749 .sh 2 "Encoding of STARTTLS and AUTH related Macros"
10751 Macros that contain STARTTLS and AUTH related data which comes from outside
10752 sources, e.g., all macros containing information from certificates,
10753 are encoded to avoid problems with non-printable or special characters.
10754 The latter are '\\', '<', '>', '(', ')', '"', '+', and ' '.
10755 All of these characters are replaced by their value in hexadecimal
10756 with a leading '+'.
10759 /C=US/ST=California/O=endmail.org/OU=private/CN=Darth Mail (Cert)/
10760 Email=darth+cert@endmail.org
10764 /C=US/ST=California/O=endmail.org/OU=private/
10765 CN=Darth+20Mail+20+28Cert+29/Email=darth+2Bcert@endmail.org
10767 (line breaks have been inserted for readability).
10768 The macros which are subject to this encoding are
10769 {cert_subject}, {cert_issuer}, {cn_subject}, {cn_issuer},
10771 {auth_authen} and {auth_author}.
10772 .sh 1 "ACKNOWLEDGEMENTS"
10777 and many employers have been remarkably patient
10778 about letting me work on a large project
10779 that was not part of my official job.
10780 This includes time on the INGRES Project at
10781 the University of California at Berkeley,
10783 and again on the Mammoth and Titan Projects at Berkeley.
10785 Much of the second wave of improvements
10786 resulting in version 8.1
10787 should be credited to Bryan Costales of the
10788 International Computer Science Institute.
10789 As he passed me drafts of his book on
10791 I was inspired to start working on things again.
10792 Bryan was also available to bounce ideas off of.
10794 Gregory Neil Shapiro
10795 of Worcester Polytechnic Institute
10796 has become instrumental in all phases of
10798 support and development,
10799 and was largely responsible for getting versions 8.8 and 8.9
10802 Many, many people contributed chunks of code and ideas to
10804 It has proven to be a group network effort.
10805 Version 8 in particular was a group project.
10806 The following people and organizations made notable contributions:
10809 John Beck, Hewlett-Packard & Sun Microsystems
10810 Keith Bostic, CSRG, University of California, Berkeley
10811 Andrew Cheng, Sun Microsystems
10812 Michael J. Corrigan, University of California, San Diego
10813 Bryan Costales, International Computer Science Institute & InfoBeat
10814 Pa\*:r (Pell) Emanuelsson
10815 Craig Everhart, Transarc Corporation
10816 Per Hedeland, Ericsson
10817 Tom Ivar Helbekkmo, Norwegian School of Economics
10818 Kari Hurtta, Finnish Meteorological Institute
10819 Allan E. Johannesen, WPI
10820 Jonathan Kamens, OpenVision Technologies, Inc.
10821 Takahiro Kanbe, Fuji Xerox Information Systems Co., Ltd.
10822 Brian Kantor, University of California, San Diego
10823 John Kennedy, Cal State University, Chico
10824 Murray S. Kucherawy, HookUp Communication Corp.
10825 Bruce Lilly, Sony U.S.
10827 Motonori Nakamura, Ritsumeikan University & Kyoto University
10828 John Gardiner Myers, Carnegie Mellon University
10829 Neil Rickert, Northern Illinois University
10830 Gregory Neil Shapiro, WPI
10831 Eric Schnoebelen, Convex Computer Corp.
10832 Eric Wassenaar, National Institute for Nuclear and High Energy Physics, Amsterdam
10833 Randall Winchester, University of Maryland
10834 Christophe Wolfhugel, Pasteur Institute & Herve Schauer Consultants (Paris)
10837 I apologize for anyone I have omitted, misspelled, misattributed, or
10839 At this point, I suspect that at least a hundred people
10840 have contributed code,
10841 and many more have contributed ideas, comments, and encouragement.
10842 I've tried to list them in the RELEASE_NOTES in the distribution directory.
10843 I appreciate their contribution as well.
10845 Special thanks are reserved for Michael Corrigan and Christophe Wolfhugel,
10846 who besides being wonderful guinea pigs and contributors
10847 have also consented to be added to the ``sendmail@Sendmail.ORG'' list
10848 and, by answering the bulk of the questions sent to that list,
10849 have freed me up to do other work.
10851 .+c "COMMAND LINE FLAGS"
10855 Arguments must be presented with flags before addresses.
10858 Select an alternative .cf file which is either
10866 By default the .cf file is chosen based on the operation mode.
10875 if it exists, for all others it is
10878 Set operation mode to
10880 Operation modes are:
10883 m Deliver mail (default)
10884 s Speak SMTP on input side
10885 a\(dg ``Arpanet'' mode (get envelope sender information from header)
10886 d Run as a daemon in background
10887 D Run as a daemon in foreground
10889 v Just verify addresses, don't collect or deliver
10890 i Initialize the alias database
10891 p Print the mail queue
10892 P Print overview over the mail queue (requires shared memory)
10893 h Print the persistent host status database
10894 H Purge expired entries from the persistent host status database
10900 Indicate body type.
10902 Use a different configuration file.
10904 runs as the invoking user (rather than root)
10905 when this flag is specified.
10906 .ip "\-D \fIlogfile\fP"
10907 Send debugging output to the indicated
10911 Set debugging level.
10912 .ip "\-f\ \fIaddr\fP"
10913 The envelope sender address is set to
10915 This address may also be used in the From: header
10916 if that header is missing during initial submission.
10917 The envelope sender address is used as the recipient
10918 for delivery status notifications
10919 and may also appear in a Return-Path: header.
10920 .ip \-F\ \fIname\fP
10921 Sets the full name of this user to
10924 When accepting messages via the command line,
10925 indicate that they are for relay (gateway) submission.
10926 sendmail may complain about syntactically invalid messages,
10927 e.g., unqualified host names,
10928 rather than fixing them when this flag is set.
10929 sendmail will not do any canonicalization in this mode.
10930 .ip "\-h\ \fIcnt\fP"
10935 This represents the number of times this message has been processed
10938 (to the extent that it is supported by the underlying networks).
10940 is incremented during processing,
10945 throws away the message with an error.
10946 .ip "\-L \fItag\fP"
10947 Sets the identifier used for syslog.
10948 Note that this identifier is set
10949 as early as possible.
10954 before the command line arguments
10957 Don't do aliasing or forwarding.
10958 .ip "\-N \fInotifications\fP"
10959 Tag all addresses being sent as wanting the indicated
10961 which consists of the word
10963 or a comma-separated list of
10968 for successful delivery,
10970 and a message that is stuck in a queue somewhere.
10973 .ip "\-r\ \fIaddr\fP"
10974 An obsolete form of
10976 .ip \-o\fIx\|value\fP
10981 These options are described in Section 5.6.
10982 .ip \-O\fIoption\fP\fB=\fP\fIvalue\fP
10987 (for long form option names).
10988 These options are described in Section 5.6.
10989 .ip \-M\fIx\|value\fP
10994 .ip \-p\fIprotocol\fP
10995 Set the sending protocol.
10996 Programs are encouraged to set this.
10997 The protocol field can be in the form
11001 to set both the sending protocol and sending host.
11004 sets the sending protocol to UUCP
11005 and the sending host to uunet.
11006 (Some existing programs use \-oM to set the r and s macros;
11007 this is equivalent to using \-p.)
11009 Try to process the queued up mail.
11010 If the time is given,
11013 will start one or more processes to run through the queue(s) at the specified
11014 time interval to deliver queued mail; otherwise, it only runs once.
11015 Each of these processes acts on a workgroup.
11016 These processes are also known as workgroup processes or WGP's for short.
11017 Each workgroup is responsible for controlling the processing of one or
11018 more queues; workgroups help manage the use of system resources by sendmail.
11019 Each workgroup may have one or more children concurrently processing
11020 queues depending on the setting of \fIMaxQueueChildren\fP.
11022 Similar to \-q with a time argument,
11023 except that instead of periodically starting WGP's
11024 sendmail starts persistent WGP's
11025 that alternate between processing queues and sleeping.
11026 The sleep time is specified by the time argument; it defaults to 1 second,
11027 except that a WGP always sleeps at least 5 seconds if their queues were
11028 empty in the previous run.
11029 Persistent processes are managed by a queue control process (QCP).
11030 The QCP is the parent process of the WGP's.
11031 Typically the QCP will be the sendmail daemon (when started with \-bd or \-bD)
11032 or a special process (named Queue control) (when started without \-bd or \-bD).
11033 If a persistent WGP ceases to be active for some reason
11034 another WGP will be started by the QCP for the same workgroup
11035 in most cases. When a persistent WGP has core dumped, the debug flag
11036 \fIno_persistent_restart\fP is set or the specific persistent WGP has been
11037 restarted too many times already then the WGP will not be started again
11038 and a message will be logged to this effect.
11039 To stop (SIGTERM) or restart (SIGHUP) persistent WGP's the appropriate
11040 signal should be sent to the QCP. The QCP will propagate the signal to all of
11041 the WGP's and if appropriate restart the persistent WGP's.
11043 Run the jobs in the queue group
11046 .ip \-q[!]\fIXstring\fP
11047 Run the queue once,
11048 limiting the jobs to those matching
11054 to limit based on queue identifier,
11056 to limit based on recipient,
11058 to limit based on sender,
11061 to limit based on quarantine reason for quarantined jobs.
11062 A particular queued job is accepted if one of the corresponding attributes
11063 contains the indicated
11065 The optional ! character negates the condition tested.
11068 flags are permitted,
11069 with items with the same key letter
11071 together, and items with different key letters
11075 Quarantine a normal queue items with the given reason or
11076 unquarantine quarantined queue items if no reason is given.
11077 This should only be used with some sort of item matching using
11078 .b \-q[!]\fIXstring\fP
11079 as described above.
11081 What information you want returned if the message bounces;
11085 for headers only or
11087 for headers plus body.
11088 This is a request only;
11089 the other end is not required to honor the parameter.
11092 is specified local bounces also return only the headers.
11094 Read the header for
11099 lines, and send to everyone listed in those lists.
11102 line will be deleted before sending.
11103 Any addresses in the argument vector will be deleted
11104 from the send list.
11108 is passed with the envelope of the message
11109 and returned if the message bounces.
11110 .ip "\-X \fIlogfile\fP"
11111 Log all traffic in and out of
11115 for debugging mailer problems.
11116 This produces a lot of data very quickly and should be used sparingly.
11118 There are a number of options that may be specified as
11120 These are the e, i, m, and v options.
11123 may be specified as the
11126 The DSN related options
11134 .+c "QUEUE FILE FORMATS"
11136 This appendix describes the format of the queue files.
11137 These files live in a queue directory.
11138 The individual qf, hf, Qf, df, and xf files
11139 may be stored in separate
11145 if they are present in the queue directory.
11147 All queue files have the name
11157 The individual letters in the
11174 Encoded envelope number
11176 At least five decimal digits of the process ID
11178 All files with the same id collectively define one message.
11179 Due to the use of memory-buffered files,
11180 some of these files may never appear on disk.
11185 The queue control file.
11186 This file contains the information necessary to process the job.
11188 The same as a queue control file, but for a quarantined queue job.
11191 The message body (excluding the header) is kept in this file.
11192 Sometimes the df file is not stored in the same directory as the qf file;
11194 the qf file contains a `d' record which names the queue directory
11195 that contains the df file.
11198 This is an image of the
11200 file when it is being rebuilt.
11201 It should be renamed to a
11206 existing during the life of a session
11207 showing everything that happens
11208 during that session.
11209 Sometimes the xf file must be generated before a queue group has been selected;
11211 the xf file will be stored in a directory of the default queue group.
11213 A ``lost'' queue control file.
11219 if there is a severe (configuration) problem that cannot be solved without
11220 human intervention.
11221 Search the logfile for the queue file id to figure out what happened.
11222 After you resolved the problem, you can rename the
11228 The queue control file is structured as a series of lines
11229 each beginning with a code letter.
11230 The lines are as follows:
11232 The version number of the queue file format,
11235 binaries to read queue files created by older versions.
11236 Defaults to version zero.
11237 Must be the first line of the file if present.
11238 For 8.12 the version number is 6.
11240 The information given by the AUTH= parameter of the
11243 if sendmail has been called directly.
11245 A header definition.
11246 There may be any number of these lines.
11247 The order is important:
11248 they represent the order in the final message.
11249 These use the same syntax
11250 as header definitions in the configuration file.
11252 The controlling address.
11254 .q localuser:aliasname .
11255 Recipient addresses following this line
11256 will be flagged so that deliveries will be run as the
11258 (a user name from the /etc/passwd file);
11260 is the name of the alias that expanded to this address
11261 (used for printing messages).
11263 The quarantine reason for quarantined queue items.
11265 The ``original recipient'',
11266 specified by the ORCPT= field in an ESMTP transaction.
11267 Used exclusively for Delivery Status Notifications.
11268 It applies only to the following `R' line.
11270 The ``final recipient''
11271 used for Delivery Status Notifications.
11272 It applies only to the following `R' line.
11274 A recipient address.
11275 This will normally be completely aliased,
11276 but is actually realiased when the job is processed.
11277 There will be one line for each recipient.
11279 also include a leading colon-terminated list of flags,
11281 `S' to return a message on successful final delivery,
11282 `F' to return a message on failure,
11283 `D' to return a message if the message is delayed,
11284 `B' to indicate that the body should be returned,
11285 `N' to suppress returning the body,
11287 `P' to declare this as a ``primary'' (command line or SMTP-session) address.
11289 The sender address.
11290 There may only be one of these lines.
11292 The job creation time.
11293 This is used to compute when to time out the job.
11295 The current message priority.
11296 This is used to order the queue.
11297 Higher numbers mean lower priorities.
11298 The priority changes
11299 as the message sits in the queue.
11300 The initial priority depends on the message class
11301 and the size of the message.
11304 This line is printed by the
11307 and is generally used to store status information.
11308 It can contain any text.
11310 Flag bits, represented as one letter per flag.
11311 Defined flag bits are
11313 indicating that this is a response message
11316 indicating that a warning message has been sent
11317 announcing that the mail has been delayed.
11318 Other flag bits are:
11320 the body contains 8bit data,
11322 a Bcc: header should be removed,
11324 the mail has RET parameters (see RFC 1894),
11326 the body of the message should not be returned
11327 in case of an error,
11329 the envelope has been split.
11331 The total number of delivery attempts.
11333 The time (as seconds since January 1, 1970)
11334 of the last delivery attempt.
11336 If the df file is in a different directory than the qf file,
11337 then a `d' record is present,
11338 specifying the directory in which the df file resides.
11340 The i-number of the data file;
11341 this can be used to recover your mail queue
11342 after a disastrous disk crash.
11344 A macro definition.
11345 The values of certain macros
11346 are passed through to the queue run phase.
11349 The remainder of the line is a text string defining the body type.
11350 If this field is missing,
11351 the body type is assumed to be
11353 and no special processing is attempted.
11359 The original envelope id (from the ESMTP transaction).
11360 For Deliver Status Notifications only.
11363 the following is a queue file sent to
11364 .q eric@mammoth.Berkeley.EDU
11366 .q bostic@okeeffe.CS.Berkeley.EDU \**:
11368 \**This example is contrived and probably inaccurate for your environment.
11369 Glance over it to get an idea;
11370 nothing can replace looking at what your own system generates.
11381 Ceric:100:1000:sendmail@vangogh.CS.Berkeley.EDU
11382 RPFD:eric@mammoth.Berkeley.EDU
11383 RPFD:bostic@okeeffe.CS.Berkeley.EDU
11384 H?P?Return-path: <^g>
11385 H??Received: by vangogh.CS.Berkeley.EDU (5.108/2.7) id AAA06703;
11386 Fri, 17 Jul 1992 00:28:55 -0700
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11393 H?F?From: eric@foo.bar.baz.de (Eric Allman)
11394 H?x?Full-name: Eric Allman
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11396 H??To: sendmail@vangogh.CS.Berkeley.EDU
11397 H??Subject: this is an example message
11400 the person who sent the message,
11401 the submission time
11402 (in seconds since January 1, 1970),
11403 the message priority,
11406 and the headers for the message.
11407 .+c "SUMMARY OF SUPPORT FILES"
11409 This is a summary of the support files
11412 creates or generates.
11413 Many of these can be changed by editing the sendmail.cf file;
11414 check there to find the actual pathnames.
11416 .ip "/usr/\*(SD/sendmail"
11419 .ip /usr/\*(SB/newaliases
11420 A link to /usr/\*(SD/sendmail;
11421 causes the alias database to be rebuilt.
11422 Running this program is completely equivalent to giving
11427 .ip /usr/\*(SB/mailq
11428 Prints a listing of the mail queue.
11429 This program is equivalent to using the
11433 .ip /etc/mail/sendmail.cf
11434 The configuration file,
11436 .ip /etc/mail/helpfile
11437 The SMTP help file.
11438 .ip /etc/mail/statistics
11439 A statistics file; need not be present.
11440 .ip /etc/mail/sendmail.pid
11441 Created in daemon mode;
11442 it contains the process id of the current SMTP daemon.
11443 If you use this in scripts;
11444 use ``head \-1'' to get just the first line;
11445 the second line contains the command line used to invoke the daemon,
11446 and later versions of
11448 may add more information to subsequent lines.
11449 .ip /etc/mail/aliases
11450 The textual version of the alias file.
11451 .ip /etc/mail/aliases.db
11455 .ip /etc/mail/aliases.{pag,dir}
11459 .ip /var/spool/mqueue
11460 The directory in which the mail queue(s)
11461 and temporary files reside.
11462 .ip /var/spool/mqueue/qf*
11463 Control (queue) files for messages.
11464 .ip /var/spool/mqueue/df*
11466 .ip /var/spool/mqueue/tf*
11467 Temporary versions of the qf files,
11468 used during queue file rebuild.
11469 .ip /var/spool/mqueue/xf*
11470 A transcript of the current session.
11477 This page intentionally left blank;
11478 replace it with a blank sheet for double-sided output.
11490 .\"INSTALLATION AND OPERATION GUIDE
11495 .\"Version $Revision: 8.759 $
11503 .\" remove some things to avoid "out of temp file space" problem
11523 This page intentionally left blank;
11524 replace it with a blank sheet for double-sided output.
projects / FreeBSD / releng / 9.3.git / blob