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[exim.git] / doc / doc-docbook / spec.xfpt
1 . /////////////////////////////////////////////////////////////////////////////
2 . This is the primary source of the Exim Manual. It is an xfpt document that is
3 . converted into DocBook XML for subsequent conversion into printing and online
4 . formats. The markup used herein is "standard" xfpt markup, with some extras.
5 . The markup is summarized in a file called Markup.txt.
6 .
7 . WARNING: When you use the .new macro, make sure it appears *before* any
8 . adjacent index items; otherwise you get an empty "paragraph" which causes
9 . unwanted vertical space.
10 . /////////////////////////////////////////////////////////////////////////////
12 .include stdflags
13 .include stdmacs
15 . /////////////////////////////////////////////////////////////////////////////
16 . This outputs the standard DocBook boilerplate.
17 . /////////////////////////////////////////////////////////////////////////////
19 .docbook
21 . /////////////////////////////////////////////////////////////////////////////
22 . These lines are processing instructions for the Simple DocBook Processor that
23 . Philip Hazel has developed as a less cumbersome way of making PostScript and
24 . PDFs than using xmlto and fop. They will be ignored by all other XML
25 . processors.
26 . /////////////////////////////////////////////////////////////////////////////
28 .literal xml
29 <?sdop
30 foot_right_recto="&chaptertitle; (&chapternumber;)"
31 foot_right_verso="&chaptertitle; (&chapternumber;)"
32 toc_chapter_blanks="yes,yes"
33 table_warn_overflow="overprint"
34 ?>
35 .literal off
37 . /////////////////////////////////////////////////////////////////////////////
38 . This generate the outermost <book> element that wraps then entire document.
39 . /////////////////////////////////////////////////////////////////////////////
41 .book
43 . /////////////////////////////////////////////////////////////////////////////
44 . These definitions set some parameters and save some typing.
45 . Update the Copyright year (only) when changing content.
46 . /////////////////////////////////////////////////////////////////////////////
48 .set previousversion "4.80"
49 .include ./local_params
51 .set ACL "access control lists (ACLs)"
52 .set I "&nbsp;&nbsp;&nbsp;&nbsp;"
54 .macro copyyear
55 2012
56 .endmacro
58 . /////////////////////////////////////////////////////////////////////////////
59 . Additional xfpt markup used by this document, over and above the default
60 . provided in the xfpt library.
61 . /////////////////////////////////////////////////////////////////////////////
63 . --- Override the &$ flag to automatically insert a $ with the variable name
65 .flag &$ $& "<varname>$" "</varname>"
67 . --- Short flags for daggers in option headings. They will always be inside
68 . --- an italic string, but we want the daggers to be roman.
70 .flag &!! "</emphasis>&dagger;<emphasis>"
71 .flag &!? "</emphasis>&Dagger;<emphasis>"
73 . --- A macro for an Exim option definition heading, generating a one-line
74 . --- table with four columns. For cases when the option name is given with
75 . --- a space, so that it can be split, a fifth argument is used for the
76 . --- index entry.
78 .macro option
79 .arg 5
80 .oindex "&%$5%&"
81 .endarg
82 .arg -5
83 .oindex "&%$1%&"
84 .endarg
85 .itable all 0 0 4 8* left 6* center 6* center 6* right
86 .row "&%$1%&" "Use: &'$2'&" "Type: &'$3'&" "Default: &'$4'&"
87 .endtable
88 .endmacro
90 . --- A macro for the common 2-column tables. The width of the first column
91 . --- is suitable for the many tables at the start of the main options chapter;
92 . --- the small number of other 2-column tables override it.
94 .macro table2 196pt 254pt
95 .itable none 0 0 2 $1 left $2 left
96 .endmacro
98 . --- A macro that generates .row, but puts &I; at the start of the first
99 . --- argument, thus indenting it. Assume a minimum of two arguments, and
100 . --- allow up to four arguments, which is as many as we'll ever need.
102 .macro irow
103 .arg 4
104 .row "&I;$1" "$2" "$3" "$4"
105 .endarg
106 .arg -4
107 .arg 3
108 .row "&I;$1" "$2" "$3"
109 .endarg
110 .arg -3
111 .row "&I;$1" "$2"
112 .endarg
113 .endarg
114 .endmacro
116 . --- Macros for option, variable, and concept index entries. For a "range"
117 . --- style of entry, use .scindex for the start and .ecindex for the end. The
118 . --- first argument of .scindex and the only argument of .ecindex must be the
119 . --- ID that ties them together.
121 .macro cindex
122 &<indexterm role="concept">&
123 &<primary>&$1&</primary>&
124 .arg 2
125 &<secondary>&$2&</secondary>&
126 .endarg
127 &</indexterm>&
128 .endmacro
130 .macro scindex
131 &<indexterm role="concept" id="$1" class="startofrange">&
132 &<primary>&$2&</primary>&
133 .arg 3
134 &<secondary>&$3&</secondary>&
135 .endarg
136 &</indexterm>&
137 .endmacro
139 .macro ecindex
140 &<indexterm role="concept" startref="$1" class="endofrange"/>&
141 .endmacro
143 .macro oindex
144 &<indexterm role="option">&
145 &<primary>&$1&</primary>&
146 .arg 2
147 &<secondary>&$2&</secondary>&
148 .endarg
149 &</indexterm>&
150 .endmacro
152 .macro vindex
153 &<indexterm role="variable">&
154 &<primary>&$1&</primary>&
155 .arg 2
156 &<secondary>&$2&</secondary>&
157 .endarg
158 &</indexterm>&
159 .endmacro
161 .macro index
162 .echo "** Don't use .index; use .cindex or .oindex or .vindex"
163 .endmacro
164 . ////////////////////////////////////////////////////////////////////////////
167 . ////////////////////////////////////////////////////////////////////////////
168 . The <bookinfo> element is removed from the XML before processing for Ascii
169 . output formats.
170 . ////////////////////////////////////////////////////////////////////////////
172 .literal xml
173 <bookinfo>
174 <title>Specification of the Exim Mail Transfer Agent</title>
175 <titleabbrev>The Exim MTA</titleabbrev>
176 <date>
177 .fulldate
178 </date>
179 <author><firstname>Exim</firstname><surname>Maintainers</surname></author>
180 <authorinitials>EM</authorinitials>
181 <revhistory><revision>
182 <revnumber>
183 .version
184 </revnumber>
185 <date>
186 .fulldate
187 </date>
188 <authorinitials>EM</authorinitials>
189 </revision></revhistory>
190 <copyright><year>
191 .copyyear
192 </year><holder>University of Cambridge</holder></copyright>
193 </bookinfo>
194 .literal off
197 . /////////////////////////////////////////////////////////////////////////////
198 . This chunk of literal XML implements index entries of the form "x, see y" and
199 . "x, see also y". However, the DocBook DTD doesn't allow <indexterm> entries
200 . at the top level, so we have to put the .chapter directive first.
201 . /////////////////////////////////////////////////////////////////////////////
203 .chapter "Introduction" "CHID1"
204 .literal xml
206 <indexterm role="variable">
207 <primary>$1, $2, etc.</primary>
208 <see><emphasis>numerical variables</emphasis></see>
209 </indexterm>
210 <indexterm role="concept">
211 <primary>address</primary>
212 <secondary>rewriting</secondary>
213 <see><emphasis>rewriting</emphasis></see>
214 </indexterm>
215 <indexterm role="concept">
216 <primary>Bounce Address Tag Validation</primary>
217 <see><emphasis>BATV</emphasis></see>
218 </indexterm>
219 <indexterm role="concept">
220 <primary>Client SMTP Authorization</primary>
221 <see><emphasis>CSA</emphasis></see>
222 </indexterm>
223 <indexterm role="concept">
224 <primary>CR character</primary>
225 <see><emphasis>carriage return</emphasis></see>
226 </indexterm>
227 <indexterm role="concept">
228 <primary>CRL</primary>
229 <see><emphasis>certificate revocation list</emphasis></see>
230 </indexterm>
231 <indexterm role="concept">
232 <primary>delivery</primary>
233 <secondary>failure report</secondary>
234 <see><emphasis>bounce message</emphasis></see>
235 </indexterm>
236 <indexterm role="concept">
237 <primary>dialup</primary>
238 <see><emphasis>intermittently connected hosts</emphasis></see>
239 </indexterm>
240 <indexterm role="concept">
241 <primary>exiscan</primary>
242 <see><emphasis>content scanning</emphasis></see>
243 </indexterm>
244 <indexterm role="concept">
245 <primary>failover</primary>
246 <see><emphasis>fallback</emphasis></see>
247 </indexterm>
248 <indexterm role="concept">
249 <primary>fallover</primary>
250 <see><emphasis>fallback</emphasis></see>
251 </indexterm>
252 <indexterm role="concept">
253 <primary>filter</primary>
254 <secondary>Sieve</secondary>
255 <see><emphasis>Sieve filter</emphasis></see>
256 </indexterm>
257 <indexterm role="concept">
258 <primary>ident</primary>
259 <see><emphasis>RFC 1413</emphasis></see>
260 </indexterm>
261 <indexterm role="concept">
262 <primary>LF character</primary>
263 <see><emphasis>linefeed</emphasis></see>
264 </indexterm>
265 <indexterm role="concept">
266 <primary>maximum</primary>
267 <seealso><emphasis>limit</emphasis></seealso>
268 </indexterm>
269 <indexterm role="concept">
270 <primary>monitor</primary>
271 <see><emphasis>Exim monitor</emphasis></see>
272 </indexterm>
273 <indexterm role="concept">
274 <primary>no_<emphasis>xxx</emphasis></primary>
275 <see>entry for xxx</see>
276 </indexterm>
277 <indexterm role="concept">
278 <primary>NUL</primary>
279 <see><emphasis>binary zero</emphasis></see>
280 </indexterm>
281 <indexterm role="concept">
282 <primary>passwd file</primary>
283 <see><emphasis>/etc/passwd</emphasis></see>
284 </indexterm>
285 <indexterm role="concept">
286 <primary>process id</primary>
287 <see><emphasis>pid</emphasis></see>
288 </indexterm>
289 <indexterm role="concept">
290 <primary>RBL</primary>
291 <see><emphasis>DNS list</emphasis></see>
292 </indexterm>
293 <indexterm role="concept">
294 <primary>redirection</primary>
295 <see><emphasis>address redirection</emphasis></see>
296 </indexterm>
297 <indexterm role="concept">
298 <primary>return path</primary>
299 <seealso><emphasis>envelope sender</emphasis></seealso>
300 </indexterm>
301 <indexterm role="concept">
302 <primary>scanning</primary>
303 <see><emphasis>content scanning</emphasis></see>
304 </indexterm>
305 <indexterm role="concept">
306 <primary>SSL</primary>
307 <see><emphasis>TLS</emphasis></see>
308 </indexterm>
309 <indexterm role="concept">
310 <primary>string</primary>
311 <secondary>expansion</secondary>
312 <see><emphasis>expansion</emphasis></see>
313 </indexterm>
314 <indexterm role="concept">
315 <primary>top bit</primary>
316 <see><emphasis>8-bit characters</emphasis></see>
317 </indexterm>
318 <indexterm role="concept">
319 <primary>variables</primary>
320 <see><emphasis>expansion, variables</emphasis></see>
321 </indexterm>
322 <indexterm role="concept">
323 <primary>zero, binary</primary>
324 <see><emphasis>binary zero</emphasis></see>
325 </indexterm>
327 .literal off
330 . /////////////////////////////////////////////////////////////////////////////
331 . This is the real start of the first chapter. See the comment above as to why
332 . we can't have the .chapter line here.
333 . chapter "Introduction"
334 . /////////////////////////////////////////////////////////////////////////////
336 Exim is a mail transfer agent (MTA) for hosts that are running Unix or
337 Unix-like operating systems. It was designed on the assumption that it would be
338 run on hosts that are permanently connected to the Internet. However, it can be
339 used on intermittently connected hosts with suitable configuration adjustments.
341 Configuration files currently exist for the following operating systems: AIX,
342 BSD/OS (aka BSDI), Darwin (Mac OS X), DGUX, Dragonfly, FreeBSD, GNU/Hurd,
343 GNU/Linux, HI-OSF (Hitachi), HI-UX, HP-UX, IRIX, MIPS RISCOS, NetBSD, OpenBSD,
344 OpenUNIX, QNX, SCO, SCO SVR4.2 (aka UNIX-SV), Solaris (aka SunOS5), SunOS4,
345 Tru64-Unix (formerly Digital UNIX, formerly DEC-OSF1), Ultrix, and Unixware.
346 Some of these operating systems are no longer current and cannot easily be
347 tested, so the configuration files may no longer work in practice.
349 There are also configuration files for compiling Exim in the Cygwin environment
350 that can be installed on systems running Windows. However, this document does
351 not contain any information about running Exim in the Cygwin environment.
353 The terms and conditions for the use and distribution of Exim are contained in
354 the file &_NOTICE_&. Exim is distributed under the terms of the GNU General
355 Public Licence, a copy of which may be found in the file &_LICENCE_&.
357 The use, supply or promotion of Exim for the purpose of sending bulk,
358 unsolicited electronic mail is incompatible with the basic aims of the program,
359 which revolve around the free provision of a service that enhances the quality
360 of personal communications. The author of Exim regards indiscriminate
361 mass-mailing as an antisocial, irresponsible abuse of the Internet.
363 Exim owes a great deal to Smail 3 and its author, Ron Karr. Without the
364 experience of running and working on the Smail 3 code, I could never have
365 contemplated starting to write a new MTA. Many of the ideas and user interfaces
366 were originally taken from Smail 3, though the actual code of Exim is entirely
367 new, and has developed far beyond the initial concept.
369 Many people, both in Cambridge and around the world, have contributed to the
370 development and the testing of Exim, and to porting it to various operating
371 systems. I am grateful to them all. The distribution now contains a file called
372 &_ACKNOWLEDGMENTS_&, in which I have started recording the names of
373 contributors.
376 .section "Exim documentation" "SECID1"
377 . Keep this example change bar when updating the documentation!
379 .new
380 .cindex "documentation"
381 This edition of the Exim specification applies to version &version() of Exim.
382 Substantive changes from the &previousversion; edition are marked in some
383 renditions of the document; this paragraph is so marked if the rendition is
384 capable of showing a change indicator.
385 .wen
387 This document is very much a reference manual; it is not a tutorial. The reader
388 is expected to have some familiarity with the SMTP mail transfer protocol and
389 with general Unix system administration. Although there are some discussions
390 and examples in places, the information is mostly organized in a way that makes
391 it easy to look up, rather than in a natural order for sequential reading.
392 Furthermore, the manual aims to cover every aspect of Exim in detail, including
393 a number of rarely-used, special-purpose features that are unlikely to be of
394 very wide interest.
396 .cindex "books about Exim"
397 An &"easier"& discussion of Exim which provides more in-depth explanatory,
398 introductory, and tutorial material can be found in a book entitled &'The Exim
399 SMTP Mail Server'& (second edition, 2007), published by UIT Cambridge
400 (&url(
402 This book also contains a chapter that gives a general introduction to SMTP and
403 Internet mail. Inevitably, however, the book is unlikely to be fully up-to-date
404 with the latest release of Exim. (Note that the earlier book about Exim,
405 published by O'Reilly, covers Exim 3, and many things have changed in Exim 4.)
407 .cindex "Debian" "information sources"
408 If you are using a Debian distribution of Exim, you will find information about
409 Debian-specific features in the file
410 &_/usr/share/doc/exim4-base/README.Debian_&.
411 The command &(man update-exim.conf)& is another source of Debian-specific
412 information.
414 .cindex "&_doc/NewStuff_&"
415 .cindex "&_doc/ChangeLog_&"
416 .cindex "change log"
417 As the program develops, there may be features in newer versions that have not
418 yet made it into this document, which is updated only when the most significant
419 digit of the fractional part of the version number changes. Specifications of
420 new features that are not yet in this manual are placed in the file
421 &_doc/NewStuff_& in the Exim distribution.
423 Some features may be classified as &"experimental"&. These may change
424 incompatibly while they are developing, or even be withdrawn. For this reason,
425 they are not documented in this manual. Information about experimental features
426 can be found in the file &_doc/experimental.txt_&.
428 All changes to the program (whether new features, bug fixes, or other kinds of
429 change) are noted briefly in the file called &_doc/ChangeLog_&.
431 .cindex "&_doc/spec.txt_&"
432 This specification itself is available as an ASCII file in &_doc/spec.txt_& so
433 that it can easily be searched with a text editor. Other files in the &_doc_&
434 directory are:
436 .table2 100pt
437 .row &_OptionLists.txt_& "list of all options in alphabetical order"
438 .row &_dbm.discuss.txt_& "discussion about DBM libraries"
439 .row &_exim.8_& "a man page of Exim's command line options"
440 .row &_experimental.txt_& "documentation of experimental features"
441 .row &_filter.txt_& "specification of the filter language"
442 .row &_Exim3.upgrade_& "upgrade notes from release 2 to release 3"
443 .row &_Exim4.upgrade_& "upgrade notes from release 3 to release 4"
444 .endtable
446 The main specification and the specification of the filtering language are also
447 available in other formats (HTML, PostScript, PDF, and Texinfo). Section
448 &<<SECTavail>>& below tells you how to get hold of these.
452 .section "FTP and web sites" "SECID2"
453 .cindex "web site"
454 .cindex "FTP site"
455 The primary site for Exim source distributions is currently the University of
456 Cambridge's FTP site, whose contents are described in &'Where to find the Exim
457 distribution'& below. In addition, there is a web site and an FTP site at
458 & These are now also hosted at the University of Cambridge. The
459 & site was previously hosted for a number of years by Energis
460 Squared, formerly Planet Online Ltd, whose support I gratefully acknowledge.
462 .cindex "wiki"
463 .cindex "FAQ"
464 As well as Exim distribution tar files, the Exim web site contains a number of
465 differently formatted versions of the documentation. A recent addition to the
466 online information is the Exim wiki (&url(,
467 which contains what used to be a separate FAQ, as well as various other
468 examples, tips, and know-how that have been contributed by Exim users.
470 .cindex Bugzilla
471 An Exim Bugzilla exists at &url( You can use
472 this to report bugs, and also to add items to the wish list. Please search
473 first to check that you are not duplicating a previous entry.
477 .section "Mailing lists" "SECID3"
478 .cindex "mailing lists" "for Exim users"
479 The following Exim mailing lists exist:
481 .table2 140pt
482 .row &''& "Moderated, low volume announcements list"
483 .row &''& "General discussion list"
484 .row &''& "Discussion of bugs, enhancements, etc."
485 .row &''& "Automated commit messages from the VCS"
486 .endtable
488 You can subscribe to these lists, change your existing subscriptions, and view
489 or search the archives via the mailing lists link on the Exim home page.
490 .cindex "Debian" "mailing list for"
491 If you are using a Debian distribution of Exim, you may wish to subscribe to
492 the Debian-specific mailing list &''&
493 via this web page:
494 .display
495 &url(
496 .endd
497 Please ask Debian-specific questions on this list and not on the general Exim
498 lists.
500 .section "Exim training" "SECID4"
501 .cindex "training courses"
502 Training courses in Cambridge (UK) used to be run annually by the author of
503 Exim, before he retired. At the time of writing, there are no plans to run
504 further Exim courses in Cambridge. However, if that changes, relevant
505 information will be posted at &url(
507 .section "Bug reports" "SECID5"
508 .cindex "bug reports"
509 .cindex "reporting bugs"
510 Reports of obvious bugs can be emailed to &''& or reported
511 via the Bugzilla (&url( However, if you are unsure
512 whether some behaviour is a bug or not, the best thing to do is to post a
513 message to the &'exim-dev'& mailing list and have it discussed.
517 .section "Where to find the Exim distribution" "SECTavail"
518 .cindex "FTP site"
519 .cindex "distribution" "ftp site"
520 The master ftp site for the Exim distribution is
521 .display
522 &**&
523 .endd
524 This is mirrored by
525 .display
526 &**&
527 .endd
528 The file references that follow are relative to the &_exim_& directories at
529 these sites. There are now quite a number of independent mirror sites around
530 the world. Those that I know about are listed in the file called &_Mirrors_&.
532 Within the &_exim_& directory there are subdirectories called &_exim3_& (for
533 previous Exim 3 distributions), &_exim4_& (for the latest Exim 4
534 distributions), and &_Testing_& for testing versions. In the &_exim4_&
535 subdirectory, the current release can always be found in files called
536 .display
537 &_exim-n.nn.tar.gz_&
538 &_exim-n.nn.tar.bz2_&
539 .endd
540 where &'n.nn'& is the highest such version number in the directory. The two
541 files contain identical data; the only difference is the type of compression.
542 The &_.bz2_& file is usually a lot smaller than the &_.gz_& file.
544 .cindex "distribution" "signing details"
545 .cindex "distribution" "public key"
546 .cindex "public key for signed distribution"
547 .new
548 The distributions will be PGP signed by an individual key of the Release
549 Coordinator. This key will have a uid containing an email address in the
550 &''& domain and will have signatures from other people, including
551 other Exim maintainers. We expect that the key will be in the "strong set" of
552 PGP keys. There should be a trust path to that key from Nigel Metheringham's
553 PGP key, a version of which can be found in the release directory in the file
554 &_nigel-pubkey.asc_&. All keys used will be available in public keyserver pools,
555 such as &''&.
557 At time of last update, releases were being made by Phil Pennock and signed with
558 key &'0x403043153903637F'&, although that key is expected to be replaced in 2013.
559 A trust path from Nigel's key to Phil's can be observed at
560 &url(
561 .wen
563 The signatures for the tar bundles are in:
564 .display
565 &_exim-n.nn.tar.gz.asc_&
566 &_exim-n.nn.tar.bz2.asc_&
567 .endd
568 For each released version, the log of changes is made separately available in a
569 separate file in the directory &_ChangeLogs_& so that it is possible to
570 find out what has changed without having to download the entire distribution.
572 .cindex "documentation" "available formats"
573 The main distribution contains ASCII versions of this specification and other
574 documentation; other formats of the documents are available in separate files
575 inside the &_exim4_& directory of the FTP site:
576 .display
577 &_exim-html-n.nn.tar.gz_&
578 &_exim-pdf-n.nn.tar.gz_&
579 &_exim-postscript-n.nn.tar.gz_&
580 &_exim-texinfo-n.nn.tar.gz_&
581 .endd
582 These tar files contain only the &_doc_& directory, not the complete
583 distribution, and are also available in &_.bz2_& as well as &_.gz_& forms.
586 .section "Limitations" "SECID6"
587 .ilist
588 .cindex "limitations of Exim"
589 .cindex "bang paths" "not handled by Exim"
590 Exim is designed for use as an Internet MTA, and therefore handles addresses in
591 RFC 2822 domain format only. It cannot handle UUCP &"bang paths"&, though
592 simple two-component bang paths can be converted by a straightforward rewriting
593 configuration. This restriction does not prevent Exim from being interfaced to
594 UUCP as a transport mechanism, provided that domain addresses are used.
595 .next
596 .cindex "domainless addresses"
597 .cindex "address" "without domain"
598 Exim insists that every address it handles has a domain attached. For incoming
599 local messages, domainless addresses are automatically qualified with a
600 configured domain value. Configuration options specify from which remote
601 systems unqualified addresses are acceptable. These are then qualified on
602 arrival.
603 .next
604 .cindex "transport" "external"
605 .cindex "external transports"
606 The only external transport mechanisms that are currently implemented are SMTP
607 and LMTP over a TCP/IP network (including support for IPv6). However, a pipe
608 transport is available, and there are facilities for writing messages to files
609 and pipes, optionally in &'batched SMTP'& format; these facilities can be used
610 to send messages to other transport mechanisms such as UUCP, provided they can
611 handle domain-style addresses. Batched SMTP input is also catered for.
612 .next
613 Exim is not designed for storing mail for dial-in hosts. When the volumes of
614 such mail are large, it is better to get the messages &"delivered"& into files
615 (that is, off Exim's queue) and subsequently passed on to the dial-in hosts by
616 other means.
617 .next
618 Although Exim does have basic facilities for scanning incoming messages, these
619 are not comprehensive enough to do full virus or spam scanning. Such operations
620 are best carried out using additional specialized software packages. If you
621 compile Exim with the content-scanning extension, straightforward interfaces to
622 a number of common scanners are provided.
623 .endlist
626 .section "Run time configuration" "SECID7"
627 Exim's run time configuration is held in a single text file that is divided
628 into a number of sections. The entries in this file consist of keywords and
629 values, in the style of Smail 3 configuration files. A default configuration
630 file which is suitable for simple online installations is provided in the
631 distribution, and is described in chapter &<<CHAPdefconfil>>& below.
634 .section "Calling interface" "SECID8"
635 .cindex "Sendmail compatibility" "command line interface"
636 Like many MTAs, Exim has adopted the Sendmail command line interface so that it
637 can be a straight replacement for &_/usr/lib/sendmail_& or
638 &_/usr/sbin/sendmail_& when sending mail, but you do not need to know anything
639 about Sendmail in order to run Exim. For actions other than sending messages,
640 Sendmail-compatible options also exist, but those that produce output (for
641 example, &%-bp%&, which lists the messages on the queue) do so in Exim's own
642 format. There are also some additional options that are compatible with Smail
643 3, and some further options that are new to Exim. Chapter &<<CHAPcommandline>>&
644 documents all Exim's command line options. This information is automatically
645 made into the man page that forms part of the Exim distribution.
647 Control of messages on the queue can be done via certain privileged command
648 line options. There is also an optional monitor program called &'eximon'&,
649 which displays current information in an X window, and which contains a menu
650 interface to Exim's command line administration options.
654 .section "Terminology" "SECID9"
655 .cindex "terminology definitions"
656 .cindex "body of message" "definition of"
657 The &'body'& of a message is the actual data that the sender wants to transmit.
658 It is the last part of a message, and is separated from the &'header'& (see
659 below) by a blank line.
661 .cindex "bounce message" "definition of"
662 When a message cannot be delivered, it is normally returned to the sender in a
663 delivery failure message or a &"non-delivery report"& (NDR). The term
664 &'bounce'& is commonly used for this action, and the error reports are often
665 called &'bounce messages'&. This is a convenient shorthand for &"delivery
666 failure error report"&. Such messages have an empty sender address in the
667 message's &'envelope'& (see below) to ensure that they cannot themselves give
668 rise to further bounce messages.
670 The term &'default'& appears frequently in this manual. It is used to qualify a
671 value which is used in the absence of any setting in the configuration. It may
672 also qualify an action which is taken unless a configuration setting specifies
673 otherwise.
675 The term &'defer'& is used when the delivery of a message to a specific
676 destination cannot immediately take place for some reason (a remote host may be
677 down, or a user's local mailbox may be full). Such deliveries are &'deferred'&
678 until a later time.
680 The word &'domain'& is sometimes used to mean all but the first component of a
681 host's name. It is &'not'& used in that sense here, where it normally refers to
682 the part of an email address following the @ sign.
684 .cindex "envelope, definition of"
685 .cindex "sender" "definition of"
686 A message in transit has an associated &'envelope'&, as well as a header and a
687 body. The envelope contains a sender address (to which bounce messages should
688 be delivered), and any number of recipient addresses. References to the
689 sender or the recipients of a message usually mean the addresses in the
690 envelope. An MTA uses these addresses for delivery, and for returning bounce
691 messages, not the addresses that appear in the header lines.
693 .cindex "message" "header, definition of"
694 .cindex "header section" "definition of"
695 The &'header'& of a message is the first part of a message's text, consisting
696 of a number of lines, each of which has a name such as &'From:'&, &'To:'&,
697 &'Subject:'&, etc. Long header lines can be split over several text lines by
698 indenting the continuations. The header is separated from the body by a blank
699 line.
701 .cindex "local part" "definition of"
702 .cindex "domain" "definition of"
703 The term &'local part'&, which is taken from RFC 2822, is used to refer to that
704 part of an email address that precedes the @ sign. The part that follows the
705 @ sign is called the &'domain'& or &'mail domain'&.
707 .cindex "local delivery" "definition of"
708 .cindex "remote delivery, definition of"
709 The terms &'local delivery'& and &'remote delivery'& are used to distinguish
710 delivery to a file or a pipe on the local host from delivery by SMTP over
711 TCP/IP to another host. As far as Exim is concerned, all hosts other than the
712 host it is running on are &'remote'&.
714 .cindex "return path" "definition of"
715 &'Return path'& is another name that is used for the sender address in a
716 message's envelope.
718 .cindex "queue" "definition of"
719 The term &'queue'& is used to refer to the set of messages awaiting delivery,
720 because this term is in widespread use in the context of MTAs. However, in
721 Exim's case the reality is more like a pool than a queue, because there is
722 normally no ordering of waiting messages.
724 .cindex "queue runner" "definition of"
725 The term &'queue runner'& is used to describe a process that scans the queue
726 and attempts to deliver those messages whose retry times have come. This term
727 is used by other MTAs, and also relates to the command &%runq%&, but in Exim
728 the waiting messages are normally processed in an unpredictable order.
730 .cindex "spool directory" "definition of"
731 The term &'spool directory'& is used for a directory in which Exim keeps the
732 messages on its queue &-- that is, those that it is in the process of
733 delivering. This should not be confused with the directory in which local
734 mailboxes are stored, which is called a &"spool directory"& by some people. In
735 the Exim documentation, &"spool"& is always used in the first sense.
742 . ////////////////////////////////////////////////////////////////////////////
743 . ////////////////////////////////////////////////////////////////////////////
745 .chapter "Incorporated code" "CHID2"
746 .cindex "incorporated code"
747 .cindex "regular expressions" "library"
748 .cindex "PCRE"
749 .cindex "OpenDMARC"
750 A number of pieces of external code are included in the Exim distribution.
752 .ilist
753 Regular expressions are supported in the main Exim program and in the
754 Exim monitor using the freely-distributable PCRE library, copyright
755 &copy; University of Cambridge. The source to PCRE is no longer shipped with
756 Exim, so you will need to use the version of PCRE shipped with your system,
757 or obtain and install the full version of the library from
758 &url(
759 .next
760 .cindex "cdb" "acknowledgment"
761 Support for the cdb (Constant DataBase) lookup method is provided by code
762 contributed by Nigel Metheringham of (at the time he contributed it) Planet
763 Online Ltd. The implementation is completely contained within the code of Exim.
764 It does not link against an external cdb library. The code contains the
765 following statements:
767 .blockquote
768 Copyright &copy; 1998 Nigel Metheringham, Planet Online Ltd
770 This program is free software; you can redistribute it and/or modify it under
771 the terms of the GNU General Public License as published by the Free Software
772 Foundation; either version 2 of the License, or (at your option) any later
773 version.
774 This code implements Dan Bernstein's Constant DataBase (cdb) spec. Information,
775 the spec and sample code for cdb can be obtained from
776 &url( This implementation borrows
777 some code from Dan Bernstein's implementation (which has no license
778 restrictions applied to it).
779 .endblockquote
780 .next
781 .cindex "SPA authentication"
782 .cindex "Samba project"
783 .cindex "Microsoft Secure Password Authentication"
784 Client support for Microsoft's &'Secure Password Authentication'& is provided
785 by code contributed by Marc Prud'hommeaux. Server support was contributed by
786 Tom Kistner. This includes code taken from the Samba project, which is released
787 under the Gnu GPL.
788 .next
789 .cindex "Cyrus"
790 .cindex "&'pwcheck'& daemon"
791 .cindex "&'pwauthd'& daemon"
792 Support for calling the Cyrus &'pwcheck'& and &'saslauthd'& daemons is provided
793 by code taken from the Cyrus-SASL library and adapted by Alexander S.
794 Sabourenkov. The permission notice appears below, in accordance with the
795 conditions expressed therein.
797 .blockquote
798 Copyright &copy; 2001 Carnegie Mellon University. All rights reserved.
800 Redistribution and use in source and binary forms, with or without
801 modification, are permitted provided that the following conditions
802 are met:
804 .olist
805 Redistributions of source code must retain the above copyright
806 notice, this list of conditions and the following disclaimer.
807 .next
808 Redistributions in binary form must reproduce the above copyright
809 notice, this list of conditions and the following disclaimer in
810 the documentation and/or other materials provided with the
811 distribution.
812 .next
813 The name &"Carnegie Mellon University"& must not be used to
814 endorse or promote products derived from this software without
815 prior written permission. For permission or any other legal
816 details, please contact
817 .display
818 Office of Technology Transfer
819 Carnegie Mellon University
820 5000 Forbes Avenue
821 Pittsburgh, PA 15213-3890
822 (412) 268-4387, fax: (412) 268-7395
824 .endd
825 .next
826 Redistributions of any form whatsoever must retain the following
827 acknowledgment:
829 &"This product includes software developed by Computing Services
830 at Carnegie Mellon University (&url("&
839 .endlist
840 .endblockquote
842 .next
843 .cindex "Exim monitor" "acknowledgment"
844 .cindex "X-windows"
845 .cindex "Athena"
846 The Exim Monitor program, which is an X-Window application, includes
847 modified versions of the Athena StripChart and TextPop widgets.
848 This code is copyright by DEC and MIT, and their permission notice appears
849 below, in accordance with the conditions expressed therein.
851 .blockquote
852 Copyright 1987, 1988 by Digital Equipment Corporation, Maynard, Massachusetts,
853 and the Massachusetts Institute of Technology, Cambridge, Massachusetts.
855 All Rights Reserved
857 Permission to use, copy, modify, and distribute this software and its
858 documentation for any purpose and without fee is hereby granted,
859 provided that the above copyright notice appear in all copies and that
860 both that copyright notice and this permission notice appear in
861 supporting documentation, and that the names of Digital or MIT not be
862 used in advertising or publicity pertaining to distribution of the
863 software without specific, written prior permission.
872 .endblockquote
874 .next
875 .cindex "opendmarc" "acknowledgment"
876 The DMARC implementation uses the OpenDMARC library which is Copyrighted by
877 The Trusted Domain Project. Portions of Exim source which use OpenDMARC
878 derived code are indicated in the respective source files. The full OpenDMARC
879 license is provided in the LICENSE.opendmarc file contained in the distributed
880 source code.
882 .next
883 Many people have contributed code fragments, some large, some small, that were
884 not covered by any specific licence requirements. It is assumed that the
885 contributors are happy to see their code incorporated into Exim under the GPL.
886 .endlist
892 . ////////////////////////////////////////////////////////////////////////////
893 . ////////////////////////////////////////////////////////////////////////////
895 .chapter "How Exim receives and delivers mail" "CHID11" &&&
896 "Receiving and delivering mail"
899 .section "Overall philosophy" "SECID10"
900 .cindex "design philosophy"
901 Exim is designed to work efficiently on systems that are permanently connected
902 to the Internet and are handling a general mix of mail. In such circumstances,
903 most messages can be delivered immediately. Consequently, Exim does not
904 maintain independent queues of messages for specific domains or hosts, though
905 it does try to send several messages in a single SMTP connection after a host
906 has been down, and it also maintains per-host retry information.
909 .section "Policy control" "SECID11"
910 .cindex "policy control" "overview"
911 Policy controls are now an important feature of MTAs that are connected to the
912 Internet. Perhaps their most important job is to stop MTAs being abused as
913 &"open relays"& by misguided individuals who send out vast amounts of
914 unsolicited junk, and want to disguise its source. Exim provides flexible
915 facilities for specifying policy controls on incoming mail:
917 .ilist
918 .cindex "&ACL;" "introduction"
919 Exim 4 (unlike previous versions of Exim) implements policy controls on
920 incoming mail by means of &'Access Control Lists'& (ACLs). Each list is a
921 series of statements that may either grant or deny access. ACLs can be used at
922 several places in the SMTP dialogue while receiving a message from a remote
923 host. However, the most common places are after each RCPT command, and at the
924 very end of the message. The sysadmin can specify conditions for accepting or
925 rejecting individual recipients or the entire message, respectively, at these
926 two points (see chapter &<<CHAPACL>>&). Denial of access results in an SMTP
927 error code.
928 .next
929 An ACL is also available for locally generated, non-SMTP messages. In this
930 case, the only available actions are to accept or deny the entire message.
931 .next
932 When Exim is compiled with the content-scanning extension, facilities are
933 provided in the ACL mechanism for passing the message to external virus and/or
934 spam scanning software. The result of such a scan is passed back to the ACL,
935 which can then use it to decide what to do with the message.
936 .next
937 When a message has been received, either from a remote host or from the local
938 host, but before the final acknowledgment has been sent, a locally supplied C
939 function called &[local_scan()]& can be run to inspect the message and decide
940 whether to accept it or not (see chapter &<<CHAPlocalscan>>&). If the message
941 is accepted, the list of recipients can be modified by the function.
942 .next
943 Using the &[local_scan()]& mechanism is another way of calling external scanner
944 software. The &%SA-Exim%& add-on package works this way. It does not require
945 Exim to be compiled with the content-scanning extension.
946 .next
947 After a message has been accepted, a further checking mechanism is available in
948 the form of the &'system filter'& (see chapter &<<CHAPsystemfilter>>&). This
949 runs at the start of every delivery process.
950 .endlist
954 .section "User filters" "SECID12"
955 .cindex "filter" "introduction"
956 .cindex "Sieve filter"
957 In a conventional Exim configuration, users are able to run private filters by
958 setting up appropriate &_.forward_& files in their home directories. See
959 chapter &<<CHAPredirect>>& (about the &(redirect)& router) for the
960 configuration needed to support this, and the separate document entitled
961 &'Exim's interfaces to mail filtering'& for user details. Two different kinds
962 of filtering are available:
964 .ilist
965 Sieve filters are written in the standard filtering language that is defined
966 by RFC 3028.
967 .next
968 Exim filters are written in a syntax that is unique to Exim, but which is more
969 powerful than Sieve, which it pre-dates.
970 .endlist
972 User filters are run as part of the routing process, described below.
976 .section "Message identification" "SECTmessiden"
977 .cindex "message ids" "details of format"
978 .cindex "format" "of message id"
979 .cindex "id of message"
980 .cindex "base62"
981 .cindex "base36"
982 .cindex "Darwin"
983 .cindex "Cygwin"
984 Every message handled by Exim is given a &'message id'& which is sixteen
985 characters long. It is divided into three parts, separated by hyphens, for
986 example &`16VDhn-0001bo-D3`&. Each part is a sequence of letters and digits,
987 normally encoding numbers in base 62. However, in the Darwin operating
988 system (Mac OS X) and when Exim is compiled to run under Cygwin, base 36
989 (avoiding the use of lower case letters) is used instead, because the message
990 id is used to construct file names, and the names of files in those systems are
991 not always case-sensitive.
993 .cindex "pid (process id)" "re-use of"
994 The detail of the contents of the message id have changed as Exim has evolved.
995 Earlier versions relied on the operating system not re-using a process id (pid)
996 within one second. On modern operating systems, this assumption can no longer
997 be made, so the algorithm had to be changed. To retain backward compatibility,
998 the format of the message id was retained, which is why the following rules are
999 somewhat eccentric:
1001 .ilist
1002 The first six characters of the message id are the time at which the message
1003 started to be received, to a granularity of one second. That is, this field
1004 contains the number of seconds since the start of the epoch (the normal Unix
1005 way of representing the date and time of day).
1006 .next
1007 After the first hyphen, the next six characters are the id of the process that
1008 received the message.
1009 .next
1010 There are two different possibilities for the final two characters:
1011 .olist
1012 .oindex "&%localhost_number%&"
1013 If &%localhost_number%& is not set, this value is the fractional part of the
1014 time of reception, normally in units of 1/2000 of a second, but for systems
1015 that must use base 36 instead of base 62 (because of case-insensitive file
1016 systems), the units are 1/1000 of a second.
1017 .next
1018 If &%localhost_number%& is set, it is multiplied by 200 (100) and added to
1019 the fractional part of the time, which in this case is in units of 1/200
1020 (1/100) of a second.
1021 .endlist
1022 .endlist
1024 After a message has been received, Exim waits for the clock to tick at the
1025 appropriate resolution before proceeding, so that if another message is
1026 received by the same process, or by another process with the same (re-used)
1027 pid, it is guaranteed that the time will be different. In most cases, the clock
1028 will already have ticked while the message was being received.
1031 .section "Receiving mail" "SECID13"
1032 .cindex "receiving mail"
1033 .cindex "message" "reception"
1034 The only way Exim can receive mail from another host is using SMTP over
1035 TCP/IP, in which case the sender and recipient addresses are transferred using
1036 SMTP commands. However, from a locally running process (such as a user's MUA),
1037 there are several possibilities:
1039 .ilist
1040 If the process runs Exim with the &%-bm%& option, the message is read
1041 non-interactively (usually via a pipe), with the recipients taken from the
1042 command line, or from the body of the message if &%-t%& is also used.
1043 .next
1044 If the process runs Exim with the &%-bS%& option, the message is also read
1045 non-interactively, but in this case the recipients are listed at the start of
1046 the message in a series of SMTP RCPT commands, terminated by a DATA
1047 command. This is so-called &"batch SMTP"& format,
1048 but it isn't really SMTP. The SMTP commands are just another way of passing
1049 envelope addresses in a non-interactive submission.
1050 .next
1051 If the process runs Exim with the &%-bs%& option, the message is read
1052 interactively, using the SMTP protocol. A two-way pipe is normally used for
1053 passing data between the local process and the Exim process.
1054 This is &"real"& SMTP and is handled in the same way as SMTP over TCP/IP. For
1055 example, the ACLs for SMTP commands are used for this form of submission.
1056 .next
1057 A local process may also make a TCP/IP call to the host's loopback address
1058 ( or any other of its IP addresses. When receiving messages, Exim
1059 does not treat the loopback address specially. It treats all such connections
1060 in the same way as connections from other hosts.
1061 .endlist
1064 .cindex "message sender, constructed by Exim"
1065 .cindex "sender" "constructed by Exim"
1066 In the three cases that do not involve TCP/IP, the sender address is
1067 constructed from the login name of the user that called Exim and a default
1068 qualification domain (which can be set by the &%qualify_domain%& configuration
1069 option). For local or batch SMTP, a sender address that is passed using the
1070 SMTP MAIL command is ignored. However, the system administrator may allow
1071 certain users (&"trusted users"&) to specify a different sender address
1072 unconditionally, or all users to specify certain forms of different sender
1073 address. The &%-f%& option or the SMTP MAIL command is used to specify these
1074 different addresses. See section &<<SECTtrustedadmin>>& for details of trusted
1075 users, and the &%untrusted_set_sender%& option for a way of allowing untrusted
1076 users to change sender addresses.
1078 Messages received by either of the non-interactive mechanisms are subject to
1079 checking by the non-SMTP ACL, if one is defined. Messages received using SMTP
1080 (either over TCP/IP, or interacting with a local process) can be checked by a
1081 number of ACLs that operate at different times during the SMTP session. Either
1082 individual recipients, or the entire message, can be rejected if local policy
1083 requirements are not met. The &[local_scan()]& function (see chapter
1084 &<<CHAPlocalscan>>&) is run for all incoming messages.
1086 Exim can be configured not to start a delivery process when a message is
1087 received; this can be unconditional, or depend on the number of incoming SMTP
1088 connections or the system load. In these situations, new messages wait on the
1089 queue until a queue runner process picks them up. However, in standard
1090 configurations under normal conditions, delivery is started as soon as a
1091 message is received.
1097 .section "Handling an incoming message" "SECID14"
1098 .cindex "spool directory" "files that hold a message"
1099 .cindex "file" "how a message is held"
1100 When Exim accepts a message, it writes two files in its spool directory. The
1101 first contains the envelope information, the current status of the message, and
1102 the header lines, and the second contains the body of the message. The names of
1103 the two spool files consist of the message id, followed by &`-H`& for the
1104 file containing the envelope and header, and &`-D`& for the data file.
1106 .cindex "spool directory" "&_input_& sub-directory"
1107 By default all these message files are held in a single directory called
1108 &_input_& inside the general Exim spool directory. Some operating systems do
1109 not perform very well if the number of files in a directory gets large; to
1110 improve performance in such cases, the &%split_spool_directory%& option can be
1111 used. This causes Exim to split up the input files into 62 sub-directories
1112 whose names are single letters or digits. When this is done, the queue is
1113 processed one sub-directory at a time instead of all at once, which can improve
1114 overall performance even when there are not enough files in each directory to
1115 affect file system performance.
1117 The envelope information consists of the address of the message's sender and
1118 the addresses of the recipients. This information is entirely separate from
1119 any addresses contained in the header lines. The status of the message includes
1120 a list of recipients who have already received the message. The format of the
1121 first spool file is described in chapter &<<CHAPspool>>&.
1123 .cindex "rewriting" "addresses"
1124 Address rewriting that is specified in the rewrite section of the configuration
1125 (see chapter &<<CHAPrewrite>>&) is done once and for all on incoming addresses,
1126 both in the header lines and the envelope, at the time the message is accepted.
1127 If during the course of delivery additional addresses are generated (for
1128 example, via aliasing), these new addresses are rewritten as soon as they are
1129 generated. At the time a message is actually delivered (transported) further
1130 rewriting can take place; because this is a transport option, it can be
1131 different for different forms of delivery. It is also possible to specify the
1132 addition or removal of certain header lines at the time the message is
1133 delivered (see chapters &<<CHAProutergeneric>>& and
1134 &<<CHAPtransportgeneric>>&).
1138 .section "Life of a message" "SECID15"
1139 .cindex "message" "life of"
1140 .cindex "message" "frozen"
1141 A message remains in the spool directory until it is completely delivered to
1142 its recipients or to an error address, or until it is deleted by an
1143 administrator or by the user who originally created it. In cases when delivery
1144 cannot proceed &-- for example, when a message can neither be delivered to its
1145 recipients nor returned to its sender, the message is marked &"frozen"& on the
1146 spool, and no more deliveries are attempted.
1148 .cindex "frozen messages" "thawing"
1149 .cindex "message" "thawing frozen"
1150 An administrator can &"thaw"& such messages when the problem has been
1151 corrected, and can also freeze individual messages by hand if necessary. In
1152 addition, an administrator can force a delivery error, causing a bounce message
1153 to be sent.
1155 .oindex "&%timeout_frozen_after%&"
1156 .oindex "&%ignore_bounce_errors_after%&"
1157 There are options called &%ignore_bounce_errors_after%& and
1158 &%timeout_frozen_after%&, which discard frozen messages after a certain time.
1159 The first applies only to frozen bounces, the second to any frozen messages.
1161 .cindex "message" "log file for"
1162 .cindex "log" "file for each message"
1163 While Exim is working on a message, it writes information about each delivery
1164 attempt to its main log file. This includes successful, unsuccessful, and
1165 delayed deliveries for each recipient (see chapter &<<CHAPlog>>&). The log
1166 lines are also written to a separate &'message log'& file for each message.
1167 These logs are solely for the benefit of the administrator, and are normally
1168 deleted along with the spool files when processing of a message is complete.
1169 The use of individual message logs can be disabled by setting
1170 &%no_message_logs%&; this might give an improvement in performance on very busy
1171 systems.
1173 .cindex "journal file"
1174 .cindex "file" "journal"
1175 All the information Exim itself needs to set up a delivery is kept in the first
1176 spool file, along with the header lines. When a successful delivery occurs, the
1177 address is immediately written at the end of a journal file, whose name is the
1178 message id followed by &`-J`&. At the end of a delivery run, if there are some
1179 addresses left to be tried again later, the first spool file (the &`-H`& file)
1180 is updated to indicate which these are, and the journal file is then deleted.
1181 Updating the spool file is done by writing a new file and renaming it, to
1182 minimize the possibility of data loss.
1184 Should the system or the program crash after a successful delivery but before
1185 the spool file has been updated, the journal is left lying around. The next
1186 time Exim attempts to deliver the message, it reads the journal file and
1187 updates the spool file before proceeding. This minimizes the chances of double
1188 deliveries caused by crashes.
1192 .section "Processing an address for delivery" "SECTprocaddress"
1193 .cindex "drivers" "definition of"
1194 .cindex "router" "definition of"
1195 .cindex "transport" "definition of"
1196 The main delivery processing elements of Exim are called &'routers'& and
1197 &'transports'&, and collectively these are known as &'drivers'&. Code for a
1198 number of them is provided in the source distribution, and compile-time options
1199 specify which ones are included in the binary. Run time options specify which
1200 ones are actually used for delivering messages.
1202 .cindex "drivers" "instance definition"
1203 Each driver that is specified in the run time configuration is an &'instance'&
1204 of that particular driver type. Multiple instances are allowed; for example,
1205 you can set up several different &(smtp)& transports, each with different
1206 option values that might specify different ports or different timeouts. Each
1207 instance has its own identifying name. In what follows we will normally use the
1208 instance name when discussing one particular instance (that is, one specific
1209 configuration of the driver), and the generic driver name when discussing
1210 the driver's features in general.
1212 A &'router'& is a driver that operates on an address, either determining how
1213 its delivery should happen, by assigning it to a specific transport, or
1214 converting the address into one or more new addresses (for example, via an
1215 alias file). A router may also explicitly choose to fail an address, causing it
1216 to be bounced.
1218 A &'transport'& is a driver that transmits a copy of the message from Exim's
1219 spool to some destination. There are two kinds of transport: for a &'local'&
1220 transport, the destination is a file or a pipe on the local host, whereas for a
1221 &'remote'& transport the destination is some other host. A message is passed
1222 to a specific transport as a result of successful routing. If a message has
1223 several recipients, it may be passed to a number of different transports.
1225 .cindex "preconditions" "definition of"
1226 An address is processed by passing it to each configured router instance in
1227 turn, subject to certain preconditions, until a router accepts the address or
1228 specifies that it should be bounced. We will describe this process in more
1229 detail shortly. First, as a simple example, we consider how each recipient
1230 address in a message is processed in a small configuration of three routers.
1232 To make this a more concrete example, it is described in terms of some actual
1233 routers, but remember, this is only an example. You can configure Exim's
1234 routers in many different ways, and there may be any number of routers in a
1235 configuration.
1237 The first router that is specified in a configuration is often one that handles
1238 addresses in domains that are not recognized specially by the local host. These
1239 are typically addresses for arbitrary domains on the Internet. A precondition
1240 is set up which looks for the special domains known to the host (for example,
1241 its own domain name), and the router is run for addresses that do &'not'&
1242 match. Typically, this is a router that looks up domains in the DNS in order to
1243 find the hosts to which this address routes. If it succeeds, the address is
1244 assigned to a suitable SMTP transport; if it does not succeed, the router is
1245 configured to fail the address.
1247 The second router is reached only when the domain is recognized as one that
1248 &"belongs"& to the local host. This router does redirection &-- also known as
1249 aliasing and forwarding. When it generates one or more new addresses from the
1250 original, each of them is routed independently from the start. Otherwise, the
1251 router may cause an address to fail, or it may simply decline to handle the
1252 address, in which case the address is passed to the next router.
1254 The final router in many configurations is one that checks to see if the
1255 address belongs to a local mailbox. The precondition may involve a check to
1256 see if the local part is the name of a login account, or it may look up the
1257 local part in a file or a database. If its preconditions are not met, or if
1258 the router declines, we have reached the end of the routers. When this happens,
1259 the address is bounced.
1263 .section "Processing an address for verification" "SECID16"
1264 .cindex "router" "for verification"
1265 .cindex "verifying address" "overview"
1266 As well as being used to decide how to deliver to an address, Exim's routers
1267 are also used for &'address verification'&. Verification can be requested as
1268 one of the checks to be performed in an ACL for incoming messages, on both
1269 sender and recipient addresses, and it can be tested using the &%-bv%& and
1270 &%-bvs%& command line options.
1272 When an address is being verified, the routers are run in &"verify mode"&. This
1273 does not affect the way the routers work, but it is a state that can be
1274 detected. By this means, a router can be skipped or made to behave differently
1275 when verifying. A common example is a configuration in which the first router
1276 sends all messages to a message-scanning program, unless they have been
1277 previously scanned. Thus, the first router accepts all addresses without any
1278 checking, making it useless for verifying. Normally, the &%no_verify%& option
1279 would be set for such a router, causing it to be skipped in verify mode.
1284 .section "Running an individual router" "SECTrunindrou"
1285 .cindex "router" "running details"
1286 .cindex "preconditions" "checking"
1287 .cindex "router" "result of running"
1288 As explained in the example above, a number of preconditions are checked before
1289 running a router. If any are not met, the router is skipped, and the address is
1290 passed to the next router. When all the preconditions on a router &'are'& met,
1291 the router is run. What happens next depends on the outcome, which is one of
1292 the following:
1294 .ilist
1295 &'accept'&: The router accepts the address, and either assigns it to a
1296 transport, or generates one or more &"child"& addresses. Processing the
1297 original address ceases,
1298 .oindex "&%unseen%&"
1299 unless the &%unseen%& option is set on the router. This option
1300 can be used to set up multiple deliveries with different routing (for example,
1301 for keeping archive copies of messages). When &%unseen%& is set, the address is
1302 passed to the next router. Normally, however, an &'accept'& return marks the
1303 end of routing.
1305 Any child addresses generated by the router are processed independently,
1306 starting with the first router by default. It is possible to change this by
1307 setting the &%redirect_router%& option to specify which router to start at for
1308 child addresses. Unlike &%pass_router%& (see below) the router specified by
1309 &%redirect_router%& may be anywhere in the router configuration.
1310 .next
1311 &'pass'&: The router recognizes the address, but cannot handle it itself. It
1312 requests that the address be passed to another router. By default the address
1313 is passed to the next router, but this can be changed by setting the
1314 &%pass_router%& option. However, (unlike &%redirect_router%&) the named router
1315 must be below the current router (to avoid loops).
1316 .next
1317 &'decline'&: The router declines to accept the address because it does not
1318 recognize it at all. By default, the address is passed to the next router, but
1319 this can be prevented by setting the &%no_more%& option. When &%no_more%& is
1320 set, all the remaining routers are skipped. In effect, &%no_more%& converts
1321 &'decline'& into &'fail'&.
1322 .next
1323 &'fail'&: The router determines that the address should fail, and queues it for
1324 the generation of a bounce message. There is no further processing of the
1325 original address unless &%unseen%& is set on the router.
1326 .next
1327 &'defer'&: The router cannot handle the address at the present time. (A
1328 database may be offline, or a DNS lookup may have timed out.) No further
1329 processing of the address happens in this delivery attempt. It is tried again
1330 next time the message is considered for delivery.
1331 .next
1332 &'error'&: There is some error in the router (for example, a syntax error in
1333 its configuration). The action is as for defer.
1334 .endlist
1336 If an address reaches the end of the routers without having been accepted by
1337 any of them, it is bounced as unrouteable. The default error message in this
1338 situation is &"unrouteable address"&, but you can set your own message by
1339 making use of the &%cannot_route_message%& option. This can be set for any
1340 router; the value from the last router that &"saw"& the address is used.
1342 Sometimes while routing you want to fail a delivery when some conditions are
1343 met but others are not, instead of passing the address on for further routing.
1344 You can do this by having a second router that explicitly fails the delivery
1345 when the relevant conditions are met. The &(redirect)& router has a &"fail"&
1346 facility for this purpose.
1349 .section "Duplicate addresses" "SECID17"
1350 .cindex "case of local parts"
1351 .cindex "address duplicate, discarding"
1352 .cindex "duplicate addresses"
1353 Once routing is complete, Exim scans the addresses that are assigned to local
1354 and remote transports, and discards any duplicates that it finds. During this
1355 check, local parts are treated as case-sensitive. This happens only when
1356 actually delivering a message; when testing routers with &%-bt%&, all the
1357 routed addresses are shown.
1361 .section "Router preconditions" "SECTrouprecon"
1362 .cindex "router" "preconditions, order of processing"
1363 .cindex "preconditions" "order of processing"
1364 The preconditions that are tested for each router are listed below, in the
1365 order in which they are tested. The individual configuration options are
1366 described in more detail in chapter &<<CHAProutergeneric>>&.
1368 .ilist
1369 The &%local_part_prefix%& and &%local_part_suffix%& options can specify that
1370 the local parts handled by the router may or must have certain prefixes and/or
1371 suffixes. If a mandatory affix (prefix or suffix) is not present, the router is
1372 skipped. These conditions are tested first. When an affix is present, it is
1373 removed from the local part before further processing, including the evaluation
1374 of any other conditions.
1375 .next
1376 Routers can be designated for use only when not verifying an address, that is,
1377 only when routing it for delivery (or testing its delivery routing). If the
1378 &%verify%& option is set false, the router is skipped when Exim is verifying an
1379 address.
1380 Setting the &%verify%& option actually sets two options, &%verify_sender%& and
1381 &%verify_recipient%&, which independently control the use of the router for
1382 sender and recipient verification. You can set these options directly if
1383 you want a router to be used for only one type of verification.
1384 Note that cutthrough delivery is classed as a recipient verification
1385 for this purpose.
1386 .next
1387 If the &%address_test%& option is set false, the router is skipped when Exim is
1388 run with the &%-bt%& option to test an address routing. This can be helpful
1389 when the first router sends all new messages to a scanner of some sort; it
1390 makes it possible to use &%-bt%& to test subsequent delivery routing without
1391 having to simulate the effect of the scanner.
1392 .next
1393 Routers can be designated for use only when verifying an address, as
1394 opposed to routing it for delivery. The &%verify_only%& option controls this.
1395 Again, cutthrough delibery counts as a verification.
1396 .next
1397 Individual routers can be explicitly skipped when running the routers to
1398 check an address given in the SMTP EXPN command (see the &%expn%& option).
1399 .next
1400 If the &%domains%& option is set, the domain of the address must be in the set
1401 of domains that it defines.
1402 .next
1403 .vindex "&$local_part_prefix$&"
1404 .vindex "&$local_part$&"
1405 .vindex "&$local_part_suffix$&"
1406 If the &%local_parts%& option is set, the local part of the address must be in
1407 the set of local parts that it defines. If &%local_part_prefix%& or
1408 &%local_part_suffix%& is in use, the prefix or suffix is removed from the local
1409 part before this check. If you want to do precondition tests on local parts
1410 that include affixes, you can do so by using a &%condition%& option (see below)
1411 that uses the variables &$local_part$&, &$local_part_prefix$&, and
1412 &$local_part_suffix$& as necessary.
1413 .next
1414 .vindex "&$local_user_uid$&"
1415 .vindex "&$local_user_gid$&"
1416 .vindex "&$home$&"
1417 If the &%check_local_user%& option is set, the local part must be the name of
1418 an account on the local host. If this check succeeds, the uid and gid of the
1419 local user are placed in &$local_user_uid$& and &$local_user_gid$& and the
1420 user's home directory is placed in &$home$&; these values can be used in the
1421 remaining preconditions.
1422 .next
1423 If the &%router_home_directory%& option is set, it is expanded at this point,
1424 because it overrides the value of &$home$&. If this expansion were left till
1425 later, the value of &$home$& as set by &%check_local_user%& would be used in
1426 subsequent tests. Having two different values of &$home$& in the same router
1427 could lead to confusion.
1428 .next
1429 If the &%senders%& option is set, the envelope sender address must be in the
1430 set of addresses that it defines.
1431 .next
1432 If the &%require_files%& option is set, the existence or non-existence of
1433 specified files is tested.
1434 .next
1435 .cindex "customizing" "precondition"
1436 If the &%condition%& option is set, it is evaluated and tested. This option
1437 uses an expanded string to allow you to set up your own custom preconditions.
1438 Expanded strings are described in chapter &<<CHAPexpand>>&.
1439 .endlist
1442 Note that &%require_files%& comes near the end of the list, so you cannot use
1443 it to check for the existence of a file in which to lookup up a domain, local
1444 part, or sender. However, as these options are all expanded, you can use the
1445 &%exists%& expansion condition to make such tests within each condition. The
1446 &%require_files%& option is intended for checking files that the router may be
1447 going to use internally, or which are needed by a specific transport (for
1448 example, &_.procmailrc_&).
1452 .section "Delivery in detail" "SECID18"
1453 .cindex "delivery" "in detail"
1454 When a message is to be delivered, the sequence of events is as follows:
1456 .ilist
1457 If a system-wide filter file is specified, the message is passed to it. The
1458 filter may add recipients to the message, replace the recipients, discard the
1459 message, cause a new message to be generated, or cause the message delivery to
1460 fail. The format of the system filter file is the same as for Exim user filter
1461 files, described in the separate document entitled &'Exim's interfaces to mail
1462 filtering'&.
1463 .cindex "Sieve filter" "not available for system filter"
1464 (&*Note*&: Sieve cannot be used for system filter files.)
1466 Some additional features are available in system filters &-- see chapter
1467 &<<CHAPsystemfilter>>& for details. Note that a message is passed to the system
1468 filter only once per delivery attempt, however many recipients it has. However,
1469 if there are several delivery attempts because one or more addresses could not
1470 be immediately delivered, the system filter is run each time. The filter
1471 condition &%first_delivery%& can be used to detect the first run of the system
1472 filter.
1473 .next
1474 Each recipient address is offered to each configured router in turn, subject to
1475 its preconditions, until one is able to handle it. If no router can handle the
1476 address, that is, if they all decline, the address is failed. Because routers
1477 can be targeted at particular domains, several locally handled domains can be
1478 processed entirely independently of each other.
1479 .next
1480 .cindex "routing" "loops in"
1481 .cindex "loop" "while routing"
1482 A router that accepts an address may assign it to a local or a remote
1483 transport. However, the transport is not run at this time. Instead, the address
1484 is placed on a list for the particular transport, which will be run later.
1485 Alternatively, the router may generate one or more new addresses (typically
1486 from alias, forward, or filter files). New addresses are fed back into this
1487 process from the top, but in order to avoid loops, a router ignores any address
1488 which has an identically-named ancestor that was processed by itself.
1489 .next
1490 When all the routing has been done, addresses that have been successfully
1491 handled are passed to their assigned transports. When local transports are
1492 doing real local deliveries, they handle only one address at a time, but if a
1493 local transport is being used as a pseudo-remote transport (for example, to
1494 collect batched SMTP messages for transmission by some other means) multiple
1495 addresses can be handled. Remote transports can always handle more than one
1496 address at a time, but can be configured not to do so, or to restrict multiple
1497 addresses to the same domain.
1498 .next
1499 Each local delivery to a file or a pipe runs in a separate process under a
1500 non-privileged uid, and these deliveries are run one at a time. Remote
1501 deliveries also run in separate processes, normally under a uid that is private
1502 to Exim (&"the Exim user"&), but in this case, several remote deliveries can be
1503 run in parallel. The maximum number of simultaneous remote deliveries for any
1504 one message is set by the &%remote_max_parallel%& option.
1505 The order in which deliveries are done is not defined, except that all local
1506 deliveries happen before any remote deliveries.
1507 .next
1508 .cindex "queue runner"
1509 When it encounters a local delivery during a queue run, Exim checks its retry
1510 database to see if there has been a previous temporary delivery failure for the
1511 address before running the local transport. If there was a previous failure,
1512 Exim does not attempt a new delivery until the retry time for the address is
1513 reached. However, this happens only for delivery attempts that are part of a
1514 queue run. Local deliveries are always attempted when delivery immediately
1515 follows message reception, even if retry times are set for them. This makes for
1516 better behaviour if one particular message is causing problems (for example,
1517 causing quota overflow, or provoking an error in a filter file).
1518 .next
1519 .cindex "delivery" "retry in remote transports"
1520 Remote transports do their own retry handling, since an address may be
1521 deliverable to one of a number of hosts, each of which may have a different
1522 retry time. If there have been previous temporary failures and no host has
1523 reached its retry time, no delivery is attempted, whether in a queue run or
1524 not. See chapter &<<CHAPretry>>& for details of retry strategies.
1525 .next
1526 If there were any permanent errors, a bounce message is returned to an
1527 appropriate address (the sender in the common case), with details of the error
1528 for each failing address. Exim can be configured to send copies of bounce
1529 messages to other addresses.
1530 .next
1531 .cindex "delivery" "deferral"
1532 If one or more addresses suffered a temporary failure, the message is left on
1533 the queue, to be tried again later. Delivery of these addresses is said to be
1534 &'deferred'&.
1535 .next
1536 When all the recipient addresses have either been delivered or bounced,
1537 handling of the message is complete. The spool files and message log are
1538 deleted, though the message log can optionally be preserved if required.
1539 .endlist
1544 .section "Retry mechanism" "SECID19"
1545 .cindex "delivery" "retry mechanism"
1546 .cindex "retry" "description of mechanism"
1547 .cindex "queue runner"
1548 Exim's mechanism for retrying messages that fail to get delivered at the first
1549 attempt is the queue runner process. You must either run an Exim daemon that
1550 uses the &%-q%& option with a time interval to start queue runners at regular
1551 intervals, or use some other means (such as &'cron'&) to start them. If you do
1552 not arrange for queue runners to be run, messages that fail temporarily at the
1553 first attempt will remain on your queue for ever. A queue runner process works
1554 its way through the queue, one message at a time, trying each delivery that has
1555 passed its retry time.
1556 You can run several queue runners at once.
1558 Exim uses a set of configured rules to determine when next to retry the failing
1559 address (see chapter &<<CHAPretry>>&). These rules also specify when Exim
1560 should give up trying to deliver to the address, at which point it generates a
1561 bounce message. If no retry rules are set for a particular host, address, and
1562 error combination, no retries are attempted, and temporary errors are treated
1563 as permanent.
1567 .section "Temporary delivery failure" "SECID20"
1568 .cindex "delivery" "temporary failure"
1569 There are many reasons why a message may not be immediately deliverable to a
1570 particular address. Failure to connect to a remote machine (because it, or the
1571 connection to it, is down) is one of the most common. Temporary failures may be
1572 detected during routing as well as during the transport stage of delivery.
1573 Local deliveries may be delayed if NFS files are unavailable, or if a mailbox
1574 is on a file system where the user is over quota. Exim can be configured to
1575 impose its own quotas on local mailboxes; where system quotas are set they will
1576 also apply.
1578 If a host is unreachable for a period of time, a number of messages may be
1579 waiting for it by the time it recovers, and sending them in a single SMTP
1580 connection is clearly beneficial. Whenever a delivery to a remote host is
1581 deferred,
1582 .cindex "hints database"
1583 Exim makes a note in its hints database, and whenever a successful
1584 SMTP delivery has happened, it looks to see if any other messages are waiting
1585 for the same host. If any are found, they are sent over the same SMTP
1586 connection, subject to a configuration limit as to the maximum number in any
1587 one connection.
1591 .section "Permanent delivery failure" "SECID21"
1592 .cindex "delivery" "permanent failure"
1593 .cindex "bounce message" "when generated"
1594 When a message cannot be delivered to some or all of its intended recipients, a
1595 bounce message is generated. Temporary delivery failures turn into permanent
1596 errors when their timeout expires. All the addresses that fail in a given
1597 delivery attempt are listed in a single message. If the original message has
1598 many recipients, it is possible for some addresses to fail in one delivery
1599 attempt and others to fail subsequently, giving rise to more than one bounce
1600 message. The wording of bounce messages can be customized by the administrator.
1601 See chapter &<<CHAPemsgcust>>& for details.
1603 .cindex "&'X-Failed-Recipients:'& header line"
1604 Bounce messages contain an &'X-Failed-Recipients:'& header line that lists the
1605 failed addresses, for the benefit of programs that try to analyse such messages
1606 automatically.
1608 .cindex "bounce message" "recipient of"
1609 A bounce message is normally sent to the sender of the original message, as
1610 obtained from the message's envelope. For incoming SMTP messages, this is the
1611 address given in the MAIL command. However, when an address is expanded via a
1612 forward or alias file, an alternative address can be specified for delivery
1613 failures of the generated addresses. For a mailing list expansion (see section
1614 &<<SECTmailinglists>>&) it is common to direct bounce messages to the manager
1615 of the list.
1619 .section "Failures to deliver bounce messages" "SECID22"
1620 .cindex "bounce message" "failure to deliver"
1621 If a bounce message (either locally generated or received from a remote host)
1622 itself suffers a permanent delivery failure, the message is left on the queue,
1623 but it is frozen, awaiting the attention of an administrator. There are options
1624 that can be used to make Exim discard such failed messages, or to keep them
1625 for only a short time (see &%timeout_frozen_after%& and
1626 &%ignore_bounce_errors_after%&).
1632 . ////////////////////////////////////////////////////////////////////////////
1633 . ////////////////////////////////////////////////////////////////////////////
1635 .chapter "Building and installing Exim" "CHID3"
1636 .scindex IIDbuex "building Exim"
1638 .section "Unpacking" "SECID23"
1639 Exim is distributed as a gzipped or bzipped tar file which, when unpacked,
1640 creates a directory with the name of the current release (for example,
1641 &_exim-&version()_&) into which the following files are placed:
1643 .table2 140pt
1644 .irow &_ACKNOWLEDGMENTS_& "contains some acknowledgments"
1645 .irow &_CHANGES_& "contains a reference to where changes are &&&
1646 documented"
1647 .irow &_LICENCE_& "the GNU General Public Licence"
1648 .irow &_Makefile_& "top-level make file"
1649 .irow &_NOTICE_& "conditions for the use of Exim"
1650 .irow &_README_& "list of files, directories and simple build &&&
1651 instructions"
1652 .endtable
1654 Other files whose names begin with &_README_& may also be present. The
1655 following subdirectories are created:
1657 .table2 140pt
1658 .irow &_Local_& "an empty directory for local configuration files"
1659 .irow &_OS_& "OS-specific files"
1660 .irow &_doc_& "documentation files"
1661 .irow &_exim_monitor_& "source files for the Exim monitor"
1662 .irow &_scripts_& "scripts used in the build process"
1663 .irow &_src_& "remaining source files"
1664 .irow &_util_& "independent utilities"
1665 .endtable
1667 The main utility programs are contained in the &_src_& directory, and are built
1668 with the Exim binary. The &_util_& directory contains a few optional scripts
1669 that may be useful to some sites.
1672 .section "Multiple machine architectures and operating systems" "SECID24"
1673 .cindex "building Exim" "multiple OS/architectures"
1674 The building process for Exim is arranged to make it easy to build binaries for
1675 a number of different architectures and operating systems from the same set of
1676 source files. Compilation does not take place in the &_src_& directory.
1677 Instead, a &'build directory'& is created for each architecture and operating
1678 system.
1679 .cindex "symbolic link" "to build directory"
1680 Symbolic links to the sources are installed in this directory, which is where
1681 the actual building takes place. In most cases, Exim can discover the machine
1682 architecture and operating system for itself, but the defaults can be
1683 overridden if necessary.
1686 .section "PCRE library" "SECTpcre"
1687 .cindex "PCRE library"
1688 Exim no longer has an embedded PCRE library as the vast majority of
1689 modern systems include PCRE as a system library, although you may need
1690 to install the PCRE or PCRE development package for your operating
1691 system. If your system has a normal PCRE installation the Exim build
1692 process will need no further configuration. If the library or the
1693 headers are in an unusual location you will need to either set the PCRE_LIBS
1694 and INCLUDE directives appropriately,
1695 or set PCRE_CONFIG=yes to use the installed &(pcre-config)& command.
1696 If your operating system has no
1697 PCRE support then you will need to obtain and build the current PCRE
1698 from &url(
1699 More information on PCRE is available at &url(
1701 .section "DBM libraries" "SECTdb"
1702 .cindex "DBM libraries" "discussion of"
1703 .cindex "hints database" "DBM files used for"
1704 Even if you do not use any DBM files in your configuration, Exim still needs a
1705 DBM library in order to operate, because it uses indexed files for its hints
1706 databases. Unfortunately, there are a number of DBM libraries in existence, and
1707 different operating systems often have different ones installed.
1709 .cindex "Solaris" "DBM library for"
1710 .cindex "IRIX, DBM library for"
1711 .cindex "BSD, DBM library for"
1712 .cindex "Linux, DBM library for"
1713 If you are using Solaris, IRIX, one of the modern BSD systems, or a modern
1714 Linux distribution, the DBM configuration should happen automatically, and you
1715 may be able to ignore this section. Otherwise, you may have to learn more than
1716 you would like about DBM libraries from what follows.
1718 .cindex "&'ndbm'& DBM library"
1719 Licensed versions of Unix normally contain a library of DBM functions operating
1720 via the &'ndbm'& interface, and this is what Exim expects by default. Free
1721 versions of Unix seem to vary in what they contain as standard. In particular,
1722 some early versions of Linux have no default DBM library, and different
1723 distributors have chosen to bundle different libraries with their packaged
1724 versions. However, the more recent releases seem to have standardized on the
1725 Berkeley DB library.
1727 Different DBM libraries have different conventions for naming the files they
1728 use. When a program opens a file called &_dbmfile_&, there are several
1729 possibilities:
1731 .olist
1732 A traditional &'ndbm'& implementation, such as that supplied as part of
1733 Solaris, operates on two files called &_dbmfile.dir_& and &_dbmfile.pag_&.
1734 .next
1735 .cindex "&'gdbm'& DBM library"
1736 The GNU library, &'gdbm'&, operates on a single file. If used via its &'ndbm'&
1737 compatibility interface it makes two different hard links to it with names
1738 &_dbmfile.dir_& and &_dbmfile.pag_&, but if used via its native interface, the
1739 file name is used unmodified.
1740 .next
1741 .cindex "Berkeley DB library"
1742 The Berkeley DB package, if called via its &'ndbm'& compatibility interface,
1743 operates on a single file called &_dbmfile.db_&, but otherwise looks to the
1744 programmer exactly the same as the traditional &'ndbm'& implementation.
1745 .next
1746 If the Berkeley package is used in its native mode, it operates on a single
1747 file called &_dbmfile_&; the programmer's interface is somewhat different to
1748 the traditional &'ndbm'& interface.
1749 .next
1750 To complicate things further, there are several very different versions of the
1751 Berkeley DB package. Version 1.85 was stable for a very long time, releases
1752 2.&'x'& and 3.&'x'& were current for a while, but the latest versions are now
1753 numbered 4.&'x'&. Maintenance of some of the earlier releases has ceased. All
1754 versions of Berkeley DB can be obtained from
1755 &url(
1756 .next
1757 .cindex "&'tdb'& DBM library"
1758 Yet another DBM library, called &'tdb'&, is available from
1759 &url( It has its own interface, and also
1760 operates on a single file.
1761 .endlist
1763 .cindex "USE_DB"
1764 .cindex "DBM libraries" "configuration for building"
1765 Exim and its utilities can be compiled to use any of these interfaces. In order
1766 to use any version of the Berkeley DB package in native mode, you must set
1767 USE_DB in an appropriate configuration file (typically
1768 &_Local/Makefile_&). For example:
1769 .code
1770 USE_DB=yes
1771 .endd
1772 Similarly, for gdbm you set USE_GDBM, and for tdb you set USE_TDB. An
1773 error is diagnosed if you set more than one of these.
1775 At the lowest level, the build-time configuration sets none of these options,
1776 thereby assuming an interface of type (1). However, some operating system
1777 configuration files (for example, those for the BSD operating systems and
1778 Linux) assume type (4) by setting USE_DB as their default, and the
1779 configuration files for Cygwin set USE_GDBM. Anything you set in
1780 &_Local/Makefile_&, however, overrides these system defaults.
1782 As well as setting USE_DB, USE_GDBM, or USE_TDB, it may also be
1783 necessary to set DBMLIB, to cause inclusion of the appropriate library, as
1784 in one of these lines:
1785 .code
1786 DBMLIB = -ldb
1787 DBMLIB = -ltdb
1788 .endd
1789 Settings like that will work if the DBM library is installed in the standard
1790 place. Sometimes it is not, and the library's header file may also not be in
1791 the default path. You may need to set INCLUDE to specify where the header
1792 file is, and to specify the path to the library more fully in DBMLIB, as in
1793 this example:
1794 .code
1795 INCLUDE=-I/usr/local/include/db-4.1
1796 DBMLIB=/usr/local/lib/db-4.1/libdb.a
1797 .endd
1798 There is further detailed discussion about the various DBM libraries in the
1799 file &_doc/dbm.discuss.txt_& in the Exim distribution.
1803 .section "Pre-building configuration" "SECID25"
1804 .cindex "building Exim" "pre-building configuration"
1805 .cindex "configuration for building Exim"
1806 .cindex "&_Local/Makefile_&"
1807 .cindex "&_src/EDITME_&"
1808 Before building Exim, a local configuration file that specifies options
1809 independent of any operating system has to be created with the name
1810 &_Local/Makefile_&. A template for this file is supplied as the file
1811 &_src/EDITME_&, and it contains full descriptions of all the option settings
1812 therein. These descriptions are therefore not repeated here. If you are
1813 building Exim for the first time, the simplest thing to do is to copy
1814 &_src/EDITME_& to &_Local/Makefile_&, then read it and edit it appropriately.
1816 There are three settings that you must supply, because Exim will not build
1817 without them. They are the location of the run time configuration file
1818 (CONFIGURE_FILE), the directory in which Exim binaries will be installed
1819 (BIN_DIRECTORY), and the identity of the Exim user (EXIM_USER and
1820 maybe EXIM_GROUP as well). The value of CONFIGURE_FILE can in fact be
1821 a colon-separated list of file names; Exim uses the first of them that exists.
1823 There are a few other parameters that can be specified either at build time or
1824 at run time, to enable the same binary to be used on a number of different
1825 machines. However, if the locations of Exim's spool directory and log file
1826 directory (if not within the spool directory) are fixed, it is recommended that
1827 you specify them in &_Local/Makefile_& instead of at run time, so that errors
1828 detected early in Exim's execution (such as a malformed configuration file) can
1829 be logged.
1831 .cindex "content scanning" "specifying at build time"
1832 Exim's interfaces for calling virus and spam scanning software directly from
1833 access control lists are not compiled by default. If you want to include these
1834 facilities, you need to set
1835 .code
1837 .endd
1838 in your &_Local/Makefile_&. For details of the facilities themselves, see
1839 chapter &<<CHAPexiscan>>&.
1842 .cindex "&_Local/eximon.conf_&"
1843 .cindex "&_exim_monitor/EDITME_&"
1844 If you are going to build the Exim monitor, a similar configuration process is
1845 required. The file &_exim_monitor/EDITME_& must be edited appropriately for
1846 your installation and saved under the name &_Local/eximon.conf_&. If you are
1847 happy with the default settings described in &_exim_monitor/EDITME_&,
1848 &_Local/eximon.conf_& can be empty, but it must exist.
1850 This is all the configuration that is needed in straightforward cases for known
1851 operating systems. However, the building process is set up so that it is easy
1852 to override options that are set by default or by operating-system-specific
1853 configuration files, for example to change the name of the C compiler, which
1854 defaults to &%gcc%&. See section &<<SECToverride>>& below for details of how to
1855 do this.
1859 .section "Support for iconv()" "SECID26"
1860 .cindex "&[iconv()]& support"
1861 .cindex "RFC 2047"
1862 The contents of header lines in messages may be encoded according to the rules
1863 described RFC 2047. This makes it possible to transmit characters that are not
1864 in the ASCII character set, and to label them as being in a particular
1865 character set. When Exim is inspecting header lines by means of the &%$h_%&
1866 mechanism, it decodes them, and translates them into a specified character set
1867 (default ISO-8859-1). The translation is possible only if the operating system
1868 supports the &[iconv()]& function.
1870 However, some of the operating systems that supply &[iconv()]& do not support
1871 very many conversions. The GNU &%libiconv%& library (available from
1872 &url( can be installed on such
1873 systems to remedy this deficiency, as well as on systems that do not supply
1874 &[iconv()]& at all. After installing &%libiconv%&, you should add
1875 .code
1876 HAVE_ICONV=yes
1877 .endd
1878 to your &_Local/Makefile_& and rebuild Exim.
1882 .section "Including TLS/SSL encryption support" "SECTinctlsssl"
1883 .cindex "TLS" "including support for TLS"
1884 .cindex "encryption" "including support for"
1885 .cindex "SUPPORT_TLS"
1886 .cindex "OpenSSL" "building Exim with"
1887 .cindex "GnuTLS" "building Exim with"
1888 Exim can be built to support encrypted SMTP connections, using the STARTTLS
1889 command as per RFC 2487. It can also support legacy clients that expect to
1890 start a TLS session immediately on connection to a non-standard port (see the
1891 &%tls_on_connect_ports%& runtime option and the &%-tls-on-connect%& command
1892 line option).
1894 If you want to build Exim with TLS support, you must first install either the
1895 OpenSSL or GnuTLS library. There is no cryptographic code in Exim itself for
1896 implementing SSL.
1898 If OpenSSL is installed, you should set
1899 .code
1900 SUPPORT_TLS=yes
1901 TLS_LIBS=-lssl -lcrypto
1902 .endd
1903 in &_Local/Makefile_&. You may also need to specify the locations of the
1904 OpenSSL library and include files. For example:
1905 .code
1906 SUPPORT_TLS=yes
1907 TLS_LIBS=-L/usr/local/openssl/lib -lssl -lcrypto
1908 TLS_INCLUDE=-I/usr/local/openssl/include/
1909 .endd
1910 .cindex "pkg-config" "OpenSSL"
1911 If you have &'pkg-config'& available, then instead you can just use:
1912 .code
1913 SUPPORT_TLS=yes
1914 USE_OPENSSL_PC=openssl
1915 .endd
1916 .cindex "USE_GNUTLS"
1917 If GnuTLS is installed, you should set
1918 .code
1919 SUPPORT_TLS=yes
1920 USE_GNUTLS=yes
1921 TLS_LIBS=-lgnutls -ltasn1 -lgcrypt
1922 .endd
1923 in &_Local/Makefile_&, and again you may need to specify the locations of the
1924 library and include files. For example:
1925 .code
1926 SUPPORT_TLS=yes
1927 USE_GNUTLS=yes
1928 TLS_LIBS=-L/usr/gnu/lib -lgnutls -ltasn1 -lgcrypt
1929 TLS_INCLUDE=-I/usr/gnu/include
1930 .endd
1931 .cindex "pkg-config" "GnuTLS"
1932 If you have &'pkg-config'& available, then instead you can just use:
1933 .code
1934 SUPPORT_TLS=yes
1935 USE_GNUTLS=yes
1936 USE_GNUTLS_PC=gnutls
1937 .endd
1939 You do not need to set TLS_INCLUDE if the relevant directory is already
1940 specified in INCLUDE. Details of how to configure Exim to make use of TLS are
1941 given in chapter &<<CHAPTLS>>&.
1946 .section "Use of tcpwrappers" "SECID27"
1948 .cindex "tcpwrappers, building Exim to support"
1949 .cindex "USE_TCP_WRAPPERS"
1951 .cindex "tcp_wrappers_daemon_name"
1952 Exim can be linked with the &'tcpwrappers'& library in order to check incoming
1953 SMTP calls using the &'tcpwrappers'& control files. This may be a convenient
1954 alternative to Exim's own checking facilities for installations that are
1955 already making use of &'tcpwrappers'& for other purposes. To do this, you
1956 should set USE_TCP_WRAPPERS in &_Local/Makefile_&, arrange for the file
1957 &_tcpd.h_& to be available at compile time, and also ensure that the library
1958 &_libwrap.a_& is available at link time, typically by including &%-lwrap%& in
1959 EXTRALIBS_EXIM. For example, if &'tcpwrappers'& is installed in &_/usr/local_&,
1960 you might have
1961 .code
1963 CFLAGS=-O -I/usr/local/include
1964 EXTRALIBS_EXIM=-L/usr/local/lib -lwrap
1965 .endd
1966 in &_Local/Makefile_&. The daemon name to use in the &'tcpwrappers'& control
1967 files is &"exim"&. For example, the line
1968 .code
1969 exim : LOCAL 192.168.1. .friendly.domain.example
1970 .endd
1971 in your &_/etc/hosts.allow_& file allows connections from the local host, from
1972 the subnet, and from all hosts in &'friendly.domain.example'&.
1973 All other connections are denied. The daemon name used by &'tcpwrappers'&
1974 can be changed at build time by setting TCP_WRAPPERS_DAEMON_NAME in
1975 &_Local/Makefile_&, or by setting tcp_wrappers_daemon_name in the
1976 configure file. Consult the &'tcpwrappers'& documentation for
1977 further details.
1980 .section "Including support for IPv6" "SECID28"
1981 .cindex "IPv6" "including support for"
1982 Exim contains code for use on systems that have IPv6 support. Setting
1983 &`HAVE_IPV6=YES`& in &_Local/Makefile_& causes the IPv6 code to be included;
1984 it may also be necessary to set IPV6_INCLUDE and IPV6_LIBS on systems
1985 where the IPv6 support is not fully integrated into the normal include and
1986 library files.
1988 Two different types of DNS record for handling IPv6 addresses have been
1989 defined. AAAA records (analogous to A records for IPv4) are in use, and are
1990 currently seen as the mainstream. Another record type called A6 was proposed
1991 as better than AAAA because it had more flexibility. However, it was felt to be
1992 over-complex, and its status was reduced to &"experimental"&. It is not known
1993 if anyone is actually using A6 records. Exim has support for A6 records, but
1994 this is included only if you set &`SUPPORT_A6=YES`& in &_Local/Makefile_&. The
1995 support has not been tested for some time.
1999 .section "Dynamically loaded lookup module support" "SECTdynamicmodules"
2000 .cindex "lookup modules"
2001 .cindex "dynamic modules"
2002 .cindex ".so building"
2003 On some platforms, Exim supports not compiling all lookup types directly into
2004 the main binary, instead putting some into external modules which can be loaded
2005 on demand.
2006 This permits packagers to build Exim with support for lookups with extensive
2007 library dependencies without requiring all users to install all of those
2008 dependencies.
2009 Most, but not all, lookup types can be built this way.
2011 Set &`LOOKUP_MODULE_DIR`& to the directory into which the modules will be
2012 installed; Exim will only load modules from that directory, as a security
2013 measure. You will need to set &`CFLAGS_DYNAMIC`& if not already defined
2014 for your OS; see &_OS/Makefile-Linux_& for an example.
2015 Some other requirements for adjusting &`EXTRALIBS`& may also be necessary,
2016 see &_src/EDITME_& for details.
2018 Then, for each module to be loaded dynamically, define the relevant
2019 &`LOOKUP_`&<&'lookup_type'&> flags to have the value "2" instead of "yes".
2020 For example, this will build in lsearch but load sqlite and mysql support
2021 on demand:
2022 .code
2026 .endd
2029 .section "The building process" "SECID29"
2030 .cindex "build directory"
2031 Once &_Local/Makefile_& (and &_Local/eximon.conf_&, if required) have been
2032 created, run &'make'& at the top level. It determines the architecture and
2033 operating system types, and creates a build directory if one does not exist.
2034 For example, on a Sun system running Solaris 8, the directory
2035 &_build-SunOS5-5.8-sparc_& is created.
2036 .cindex "symbolic link" "to source files"
2037 Symbolic links to relevant source files are installed in the build directory.
2039 &*Warning*&: The &%-j%& (parallel) flag must not be used with &'make'&; the
2040 building process fails if it is set.
2042 If this is the first time &'make'& has been run, it calls a script that builds
2043 a make file inside the build directory, using the configuration files from the
2044 &_Local_& directory. The new make file is then passed to another instance of
2045 &'make'&. This does the real work, building a number of utility scripts, and
2046 then compiling and linking the binaries for the Exim monitor (if configured), a
2047 number of utility programs, and finally Exim itself. The command &`make
2048 makefile`& can be used to force a rebuild of the make file in the build
2049 directory, should this ever be necessary.
2051 If you have problems building Exim, check for any comments there may be in the
2052 &_README_& file concerning your operating system, and also take a look at the
2053 FAQ, where some common problems are covered.
2057 .section 'Output from &"make"&' "SECID283"
2058 The output produced by the &'make'& process for compile lines is often very
2059 unreadable, because these lines can be very long. For this reason, the normal
2060 output is suppressed by default, and instead output similar to that which
2061 appears when compiling the 2.6 Linux kernel is generated: just a short line for
2062 each module that is being compiled or linked. However, it is still possible to
2063 get the full output, by calling &'make'& like this:
2064 .code
2065 FULLECHO='' make -e
2066 .endd
2067 The value of FULLECHO defaults to &"@"&, the flag character that suppresses
2068 command reflection in &'make'&. When you ask for the full output, it is
2069 given in addition to the short output.
2073 .section "Overriding build-time options for Exim" "SECToverride"
2074 .cindex "build-time options, overriding"
2075 The main make file that is created at the beginning of the building process
2076 consists of the concatenation of a number of files which set configuration
2077 values, followed by a fixed set of &'make'& instructions. If a value is set
2078 more than once, the last setting overrides any previous ones. This provides a
2079 convenient way of overriding defaults. The files that are concatenated are, in
2080 order:
2081 .display
2082 &_OS/Makefile-Default_&
2083 &_OS/Makefile-_&<&'ostype'&>
2084 &_Local/Makefile_&
2085 &_Local/Makefile-_&<&'ostype'&>
2086 &_Local/Makefile-_&<&'archtype'&>
2087 &_Local/Makefile-_&<&'ostype'&>-<&'archtype'&>
2088 &_OS/Makefile-Base_&
2089 .endd
2090 .cindex "&_Local/Makefile_&"
2091 .cindex "building Exim" "operating system type"
2092 .cindex "building Exim" "architecture type"
2093 where <&'ostype'&> is the operating system type and <&'archtype'&> is the
2094 architecture type. &_Local/Makefile_& is required to exist, and the building
2095 process fails if it is absent. The other three &_Local_& files are optional,
2096 and are often not needed.
2098 The values used for <&'ostype'&> and <&'archtype'&> are obtained from scripts
2099 called &_scripts/os-type_& and &_scripts/arch-type_& respectively. If either of
2100 the environment variables EXIM_OSTYPE or EXIM_ARCHTYPE is set, their
2101 values are used, thereby providing a means of forcing particular settings.
2102 Otherwise, the scripts try to get values from the &%uname%& command. If this
2103 fails, the shell variables OSTYPE and ARCHTYPE are inspected. A number
2104 of &'ad hoc'& transformations are then applied, to produce the standard names
2105 that Exim expects. You can run these scripts directly from the shell in order
2106 to find out what values are being used on your system.
2109 &_OS/Makefile-Default_& contains comments about the variables that are set
2110 therein. Some (but not all) are mentioned below. If there is something that
2111 needs changing, review the contents of this file and the contents of the make
2112 file for your operating system (&_OS/Makefile-<ostype>_&) to see what the
2113 default values are.
2116 .cindex "building Exim" "overriding default settings"
2117 If you need to change any of the values that are set in &_OS/Makefile-Default_&
2118 or in &_OS/Makefile-<ostype>_&, or to add any new definitions, you do not
2119 need to change the original files. Instead, you should make the changes by
2120 putting the new values in an appropriate &_Local_& file. For example,
2121 .cindex "Tru64-Unix build-time settings"
2122 when building Exim in many releases of the Tru64-Unix (formerly Digital UNIX,
2123 formerly DEC-OSF1) operating system, it is necessary to specify that the C
2124 compiler is called &'cc'& rather than &'gcc'&. Also, the compiler must be
2125 called with the option &%-std1%&, to make it recognize some of the features of
2126 Standard C that Exim uses. (Most other compilers recognize Standard C by
2127 default.) To do this, you should create a file called &_Local/Makefile-OSF1_&
2128 containing the lines
2129 .code
2130 CC=cc
2131 CFLAGS=-std1
2132 .endd
2133 If you are compiling for just one operating system, it may be easier to put
2134 these lines directly into &_Local/Makefile_&.
2136 Keeping all your local configuration settings separate from the distributed
2137 files makes it easy to transfer them to new versions of Exim simply by copying
2138 the contents of the &_Local_& directory.
2141 .cindex "NIS lookup type" "including support for"
2142 .cindex "NIS+ lookup type" "including support for"
2143 .cindex "LDAP" "including support for"
2144 .cindex "lookup" "inclusion in binary"
2145 Exim contains support for doing LDAP, NIS, NIS+, and other kinds of file
2146 lookup, but not all systems have these components installed, so the default is
2147 not to include the relevant code in the binary. All the different kinds of file
2148 and database lookup that Exim supports are implemented as separate code modules
2149 which are included only if the relevant compile-time options are set. In the
2150 case of LDAP, NIS, and NIS+, the settings for &_Local/Makefile_& are:
2151 .code
2152 LOOKUP_LDAP=yes
2153 LOOKUP_NIS=yes
2155 .endd
2156 and similar settings apply to the other lookup types. They are all listed in
2157 &_src/EDITME_&. In many cases the relevant include files and interface
2158 libraries need to be installed before compiling Exim.
2159 .cindex "cdb" "including support for"
2160 However, there are some optional lookup types (such as cdb) for which
2161 the code is entirely contained within Exim, and no external include
2162 files or libraries are required. When a lookup type is not included in the
2163 binary, attempts to configure Exim to use it cause run time configuration
2164 errors.
2166 .cindex "pkg-config" "lookups"
2167 .cindex "pkg-config" "authenticators"
2168 Many systems now use a tool called &'pkg-config'& to encapsulate information
2169 about how to compile against a library; Exim has some initial support for
2170 being able to use pkg-config for lookups and authenticators. For any given
2171 makefile variable which starts &`LOOKUP_`& or &`AUTH_`&, you can add a new
2172 variable with the &`_PC`& suffix in the name and assign as the value the
2173 name of the package to be queried. The results of querying via the
2174 &'pkg-config'& command will be added to the appropriate Makefile variables
2175 with &`+=`& directives, so your version of &'make'& will need to support that
2176 syntax. For instance:
2177 .code
2179 LOOKUP_SQLITE_PC=sqlite3
2180 AUTH_GSASL=yes
2181 AUTH_GSASL_PC=libgsasl
2183 AUTH_HEIMDAL_GSSAPI_PC=heimdal-gssapi
2184 .endd
2186 .cindex "Perl" "including support for"
2187 Exim can be linked with an embedded Perl interpreter, allowing Perl
2188 subroutines to be called during string expansion. To enable this facility,
2189 .code
2190 EXIM_PERL=perl.o
2191 .endd
2192 must be defined in &_Local/Makefile_&. Details of this facility are given in
2193 chapter &<<CHAPperl>>&.
2195 .cindex "X11 libraries, location of"
2196 The location of the X11 libraries is something that varies a lot between
2197 operating systems, and there may be different versions of X11 to cope
2198 with. Exim itself makes no use of X11, but if you are compiling the Exim
2199 monitor, the X11 libraries must be available.
2200 The following three variables are set in &_OS/Makefile-Default_&:
2201 .code
2202 X11=/usr/X11R6
2203 XINCLUDE=-I$(X11)/include
2204 XLFLAGS=-L$(X11)/lib
2205 .endd
2206 These are overridden in some of the operating-system configuration files. For
2207 example, in &_OS/Makefile-SunOS5_& there is
2208 .code
2209 X11=/usr/openwin
2210 XINCLUDE=-I$(X11)/include
2211 XLFLAGS=-L$(X11)/lib -R$(X11)/lib
2212 .endd
2213 If you need to override the default setting for your operating system, place a
2214 definition of all three of these variables into your
2215 &_Local/Makefile-<ostype>_& file.
2217 .cindex "EXTRALIBS"
2218 If you need to add any extra libraries to the link steps, these can be put in a
2219 variable called EXTRALIBS, which appears in all the link commands, but by
2220 default is not defined. In contrast, EXTRALIBS_EXIM is used only on the
2221 command for linking the main Exim binary, and not for any associated utilities.
2223 .cindex "DBM libraries" "configuration for building"
2224 There is also DBMLIB, which appears in the link commands for binaries that
2225 use DBM functions (see also section &<<SECTdb>>&). Finally, there is
2226 EXTRALIBS_EXIMON, which appears only in the link step for the Exim monitor
2227 binary, and which can be used, for example, to include additional X11
2228 libraries.
2230 .cindex "configuration file" "editing"
2231 The make file copes with rebuilding Exim correctly if any of the configuration
2232 files are edited. However, if an optional configuration file is deleted, it is
2233 necessary to touch the associated non-optional file (that is,
2234 &_Local/Makefile_& or &_Local/eximon.conf_&) before rebuilding.
2237 .section "OS-specific header files" "SECID30"
2238 .cindex "&_os.h_&"
2239 .cindex "building Exim" "OS-specific C header files"
2240 The &_OS_& directory contains a number of files with names of the form
2241 &_os.h-<ostype>_&. These are system-specific C header files that should not
2242 normally need to be changed. There is a list of macro settings that are
2243 recognized in the file &_OS/os.configuring_&, which should be consulted if you
2244 are porting Exim to a new operating system.
2248 .section "Overriding build-time options for the monitor" "SECID31"
2249 .cindex "building Eximon"
2250 A similar process is used for overriding things when building the Exim monitor,
2251 where the files that are involved are
2252 .display
2253 &_OS/eximon.conf-Default_&
2254 &_OS/eximon.conf-_&<&'ostype'&>
2255 &_Local/eximon.conf_&
2256 &_Local/eximon.conf-_&<&'ostype'&>
2257 &_Local/eximon.conf-_&<&'archtype'&>
2258 &_Local/eximon.conf-_&<&'ostype'&>-<&'archtype'&>
2259 .endd
2260 .cindex "&_Local/eximon.conf_&"
2261 As with Exim itself, the final three files need not exist, and in this case the
2262 &_OS/eximon.conf-<ostype>_& file is also optional. The default values in
2263 &_OS/eximon.conf-Default_& can be overridden dynamically by setting environment
2264 variables of the same name, preceded by EXIMON_. For example, setting
2265 EXIMON_LOG_DEPTH in the environment overrides the value of
2266 LOG_DEPTH at run time.
2267 .ecindex IIDbuex
2270 .section "Installing Exim binaries and scripts" "SECID32"
2271 .cindex "installing Exim"
2272 .cindex "BIN_DIRECTORY"
2273 The command &`make install`& runs the &(exim_install)& script with no
2274 arguments. The script copies binaries and utility scripts into the directory
2275 whose name is specified by the BIN_DIRECTORY setting in &_Local/Makefile_&.
2276 .cindex "setuid" "installing Exim with"
2277 The install script copies files only if they are newer than the files they are
2278 going to replace. The Exim binary is required to be owned by root and have the
2279 &'setuid'& bit set, for normal configurations. Therefore, you must run &`make
2280 install`& as root so that it can set up the Exim binary in this way. However, in
2281 some special situations (for example, if a host is doing no local deliveries)
2282 it may be possible to run Exim without making the binary setuid root (see
2283 chapter &<<CHAPsecurity>>& for details).
2285 .cindex "CONFIGURE_FILE"
2286 Exim's run time configuration file is named by the CONFIGURE_FILE setting
2287 in &_Local/Makefile_&. If this names a single file, and the file does not
2288 exist, the default configuration file &_src/configure.default_& is copied there
2289 by the installation script. If a run time configuration file already exists, it
2290 is left alone. If CONFIGURE_FILE is a colon-separated list, naming several
2291 alternative files, no default is installed.
2293 .cindex "system aliases file"
2294 .cindex "&_/etc/aliases_&"
2295 One change is made to the default configuration file when it is installed: the
2296 default configuration contains a router that references a system aliases file.
2297 The path to this file is set to the value specified by
2298 SYSTEM_ALIASES_FILE in &_Local/Makefile_& (&_/etc/aliases_& by default).
2299 If the system aliases file does not exist, the installation script creates it,
2300 and outputs a comment to the user.
2302 The created file contains no aliases, but it does contain comments about the
2303 aliases a site should normally have. Mail aliases have traditionally been
2304 kept in &_/etc/aliases_&. However, some operating systems are now using
2305 &_/etc/mail/aliases_&. You should check if yours is one of these, and change
2306 Exim's configuration if necessary.
2308 The default configuration uses the local host's name as the only local domain,
2309 and is set up to do local deliveries into the shared directory &_/var/mail_&,
2310 running as the local user. System aliases and &_.forward_& files in users' home
2311 directories are supported, but no NIS or NIS+ support is configured. Domains
2312 other than the name of the local host are routed using the DNS, with delivery
2313 over SMTP.
2315 It is possible to install Exim for special purposes (such as building a binary
2316 distribution) in a private part of the file system. You can do this by a
2317 command such as
2318 .code
2319 make DESTDIR=/some/directory/ install
2320 .endd
2321 This has the effect of pre-pending the specified directory to all the file
2322 paths, except the name of the system aliases file that appears in the default
2323 configuration. (If a default alias file is created, its name &'is'& modified.)
2324 For backwards compatibility, ROOT is used if DESTDIR is not set,
2325 but this usage is deprecated.
2327 .cindex "installing Exim" "what is not installed"
2328 Running &'make install'& does not copy the Exim 4 conversion script
2329 &'convert4r4'&. You will probably run this only once if you are
2330 upgrading from Exim 3. None of the documentation files in the &_doc_&
2331 directory are copied, except for the info files when you have set
2332 INFO_DIRECTORY, as described in section &<<SECTinsinfdoc>>& below.
2334 For the utility programs, old versions are renamed by adding the suffix &_.O_&
2335 to their names. The Exim binary itself, however, is handled differently. It is
2336 installed under a name that includes the version number and the compile number,
2337 for example &_exim-&version()-1_&. The script then arranges for a symbolic link
2338 called &_exim_& to point to the binary. If you are updating a previous version
2339 of Exim, the script takes care to ensure that the name &_exim_& is never absent
2340 from the directory (as seen by other processes).
2342 .cindex "installing Exim" "testing the script"
2343 If you want to see what the &'make install'& will do before running it for
2344 real, you can pass the &%-n%& option to the installation script by this
2345 command:
2346 .code
2347 make INSTALL_ARG=-n install
2348 .endd
2349 The contents of the variable INSTALL_ARG are passed to the installation
2350 script. You do not need to be root to run this test. Alternatively, you can run
2351 the installation script directly, but this must be from within the build
2352 directory. For example, from the top-level Exim directory you could use this
2353 command:
2354 .code
2355 (cd build-SunOS5-5.5.1-sparc; ../scripts/exim_install -n)
2356 .endd
2357 .cindex "installing Exim" "install script options"
2358 There are two other options that can be supplied to the installation script.
2360 .ilist
2361 &%-no_chown%& bypasses the call to change the owner of the installed binary
2362 to root, and the call to make it a setuid binary.
2363 .next
2364 &%-no_symlink%& bypasses the setting up of the symbolic link &_exim_& to the
2365 installed binary.
2366 .endlist
2368 INSTALL_ARG can be used to pass these options to the script. For example:
2369 .code
2370 make INSTALL_ARG=-no_symlink install
2371 .endd
2372 The installation script can also be given arguments specifying which files are
2373 to be copied. For example, to install just the Exim binary, and nothing else,
2374 without creating the symbolic link, you could use:
2375 .code
2376 make INSTALL_ARG='-no_symlink exim' install
2377 .endd
2381 .section "Installing info documentation" "SECTinsinfdoc"
2382 .cindex "installing Exim" "&'info'& documentation"
2383 Not all systems use the GNU &'info'& system for documentation, and for this
2384 reason, the Texinfo source of Exim's documentation is not included in the main
2385 distribution. Instead it is available separately from the ftp site (see section
2386 &<<SECTavail>>&).
2388 If you have defined INFO_DIRECTORY in &_Local/Makefile_& and the Texinfo
2389 source of the documentation is found in the source tree, running &`make
2390 install`& automatically builds the info files and installs them.
2394 .section "Setting up the spool directory" "SECID33"
2395 .cindex "spool directory" "creating"
2396 When it starts up, Exim tries to create its spool directory if it does not
2397 exist. The Exim uid and gid are used for the owner and group of the spool
2398 directory. Sub-directories are automatically created in the spool directory as
2399 necessary.
2404 .section "Testing" "SECID34"
2405 .cindex "testing" "installation"
2406 Having installed Exim, you can check that the run time configuration file is
2407 syntactically valid by running the following command, which assumes that the
2408 Exim binary directory is within your PATH environment variable:
2409 .code
2410 exim -bV
2411 .endd
2412 If there are any errors in the configuration file, Exim outputs error messages.
2413 Otherwise it outputs the version number and build date,
2414 the DBM library that is being used, and information about which drivers and
2415 other optional code modules are included in the binary.
2416 Some simple routing tests can be done by using the address testing option. For
2417 example,
2418 .display
2419 &`exim -bt`& <&'local username'&>
2420 .endd
2421 should verify that it recognizes a local mailbox, and
2422 .display
2423 &`exim -bt`& <&'remote address'&>
2424 .endd
2425 a remote one. Then try getting it to deliver mail, both locally and remotely.
2426 This can be done by passing messages directly to Exim, without going through a
2427 user agent. For example:
2428 .code
2429 exim -v postmaster@your.domain.example
2430 From: user@your.domain.example
2431 To: postmaster@your.domain.example
2432 Subject: Testing Exim
2434 This is a test message.
2435 ^D
2436 .endd
2437 The &%-v%& option causes Exim to output some verification of what it is doing.
2438 In this case you should see copies of three log lines, one for the message's
2439 arrival, one for its delivery, and one containing &"Completed"&.
2441 .cindex "delivery" "problems with"
2442 If you encounter problems, look at Exim's log files (&'mainlog'& and
2443 &'paniclog'&) to see if there is any relevant information there. Another source
2444 of information is running Exim with debugging turned on, by specifying the
2445 &%-d%& option. If a message is stuck on Exim's spool, you can force a delivery
2446 with debugging turned on by a command of the form
2447 .display
2448 &`exim -d -M`& <&'exim-message-id'&>
2449 .endd
2450 You must be root or an &"admin user"& in order to do this. The &%-d%& option
2451 produces rather a lot of output, but you can cut this down to specific areas.
2452 For example, if you use &%-d-all+route%& only the debugging information
2453 relevant to routing is included. (See the &%-d%& option in chapter
2454 &<<CHAPcommandline>>& for more details.)
2456 .cindex '&"sticky"& bit'
2457 .cindex "lock files"
2458 One specific problem that has shown up on some sites is the inability to do
2459 local deliveries into a shared mailbox directory, because it does not have the
2460 &"sticky bit"& set on it. By default, Exim tries to create a lock file before
2461 writing to a mailbox file, and if it cannot create the lock file, the delivery
2462 is deferred. You can get round this either by setting the &"sticky bit"& on the
2463 directory, or by setting a specific group for local deliveries and allowing
2464 that group to create files in the directory (see the comments above the
2465 &(local_delivery)& transport in the default configuration file). Another
2466 approach is to configure Exim not to use lock files, but just to rely on
2467 &[fcntl()]& locking instead. However, you should do this only if all user
2468 agents also use &[fcntl()]& locking. For further discussion of locking issues,
2469 see chapter &<<CHAPappendfile>>&.
2471 One thing that cannot be tested on a system that is already running an MTA is
2472 the receipt of incoming SMTP mail on the standard SMTP port. However, the
2473 &%-oX%& option can be used to run an Exim daemon that listens on some other
2474 port, or &'inetd'& can be used to do this. The &%-bh%& option and the
2475 &'exim_checkaccess'& utility can be used to check out policy controls on
2476 incoming SMTP mail.
2478 Testing a new version on a system that is already running Exim can most easily
2479 be done by building a binary with a different CONFIGURE_FILE setting. From
2480 within the run time configuration, all other file and directory names
2481 that Exim uses can be altered, in order to keep it entirely clear of the
2482 production version.
2485 .section "Replacing another MTA with Exim" "SECID35"
2486 .cindex "replacing another MTA"
2487 Building and installing Exim for the first time does not of itself put it in
2488 general use. The name by which the system's MTA is called by mail user agents
2489 is either &_/usr/sbin/sendmail_&, or &_/usr/lib/sendmail_& (depending on the
2490 operating system), and it is necessary to make this name point to the &'exim'&
2491 binary in order to get the user agents to pass messages to Exim. This is
2492 normally done by renaming any existing file and making &_/usr/sbin/sendmail_&
2493 or &_/usr/lib/sendmail_&
2494 .cindex "symbolic link" "to &'exim'& binary"
2495 a symbolic link to the &'exim'& binary. It is a good idea to remove any setuid
2496 privilege and executable status from the old MTA. It is then necessary to stop
2497 and restart the mailer daemon, if one is running.
2499 .cindex "FreeBSD, MTA indirection"
2500 .cindex "&_/etc/mail/mailer.conf_&"
2501 Some operating systems have introduced alternative ways of switching MTAs. For
2502 example, if you are running FreeBSD, you need to edit the file
2503 &_/etc/mail/mailer.conf_& instead of setting up a symbolic link as just
2504 described. A typical example of the contents of this file for running Exim is
2505 as follows:
2506 .code
2507 sendmail /usr/exim/bin/exim
2508 send-mail /usr/exim/bin/exim
2509 mailq /usr/exim/bin/exim -bp
2510 newaliases /usr/bin/true
2511 .endd
2512 Once you have set up the symbolic link, or edited &_/etc/mail/mailer.conf_&,
2513 your Exim installation is &"live"&. Check it by sending a message from your
2514 favourite user agent.
2516 You should consider what to tell your users about the change of MTA. Exim may
2517 have different capabilities to what was previously running, and there are
2518 various operational differences such as the text of messages produced by
2519 command line options and in bounce messages. If you allow your users to make
2520 use of Exim's filtering capabilities, you should make the document entitled
2521 &'Exim's interface to mail filtering'& available to them.
2525 .section "Upgrading Exim" "SECID36"
2526 .cindex "upgrading Exim"
2527 If you are already running Exim on your host, building and installing a new
2528 version automatically makes it available to MUAs, or any other programs that
2529 call the MTA directly. However, if you are running an Exim daemon, you do need
2530 to send it a HUP signal, to make it re-execute itself, and thereby pick up the
2531 new binary. You do not need to stop processing mail in order to install a new
2532 version of Exim. The install script does not modify an existing runtime
2533 configuration file.
2538 .section "Stopping the Exim daemon on Solaris" "SECID37"
2539 .cindex "Solaris" "stopping Exim on"
2540 The standard command for stopping the mailer daemon on Solaris is
2541 .code
2542 /etc/init.d/sendmail stop
2543 .endd
2544 If &_/usr/lib/sendmail_& has been turned into a symbolic link, this script
2545 fails to stop Exim because it uses the command &'ps -e'& and greps the output
2546 for the text &"sendmail"&; this is not present because the actual program name
2547 (that is, &"exim"&) is given by the &'ps'& command with these options. A
2548 solution is to replace the line that finds the process id with something like
2549 .code
2550 pid=`cat /var/spool/exim/`
2551 .endd
2552 to obtain the daemon's pid directly from the file that Exim saves it in.
2554 Note, however, that stopping the daemon does not &"stop Exim"&. Messages can
2555 still be received from local processes, and if automatic delivery is configured
2556 (the normal case), deliveries will still occur.
2561 . ////////////////////////////////////////////////////////////////////////////
2562 . ////////////////////////////////////////////////////////////////////////////
2564 .chapter "The Exim command line" "CHAPcommandline"
2565 .scindex IIDclo1 "command line" "options"
2566 .scindex IIDclo2 "options" "command line"
2567 Exim's command line takes the standard Unix form of a sequence of options,
2568 each starting with a hyphen character, followed by a number of arguments. The
2569 options are compatible with the main options of Sendmail, and there are also
2570 some additional options, some of which are compatible with Smail 3. Certain
2571 combinations of options do not make sense, and provoke an error if used.
2572 The form of the arguments depends on which options are set.
2575 .section "Setting options by program name" "SECID38"
2576 .cindex "&'mailq'&"
2577 If Exim is called under the name &'mailq'&, it behaves as if the option &%-bp%&
2578 were present before any other options.
2579 The &%-bp%& option requests a listing of the contents of the mail queue on the
2580 standard output.
2581 This feature is for compatibility with some systems that contain a command of
2582 that name in one of the standard libraries, symbolically linked to
2583 &_/usr/sbin/sendmail_& or &_/usr/lib/sendmail_&.
2585 .cindex "&'rsmtp'&"
2586 If Exim is called under the name &'rsmtp'& it behaves as if the option &%-bS%&
2587 were present before any other options, for compatibility with Smail. The
2588 &%-bS%& option is used for reading in a number of messages in batched SMTP
2589 format.
2591 .cindex "&'rmail'&"
2592 If Exim is called under the name &'rmail'& it behaves as if the &%-i%& and
2593 &%-oee%& options were present before any other options, for compatibility with
2594 Smail. The name &'rmail'& is used as an interface by some UUCP systems.
2596 .cindex "&'runq'&"
2597 .cindex "queue runner"
2598 If Exim is called under the name &'runq'& it behaves as if the option &%-q%&
2599 were present before any other options, for compatibility with Smail. The &%-q%&
2600 option causes a single queue runner process to be started.
2602 .cindex "&'newaliases'&"
2603 .cindex "alias file" "building"
2604 .cindex "Sendmail compatibility" "calling Exim as &'newaliases'&"
2605 If Exim is called under the name &'newaliases'& it behaves as if the option
2606 &%-bi%& were present before any other options, for compatibility with Sendmail.
2607 This option is used for rebuilding Sendmail's alias file. Exim does not have
2608 the concept of a single alias file, but can be configured to run a given
2609 command if called with the &%-bi%& option.
2612 .section "Trusted and admin users" "SECTtrustedadmin"
2613 Some Exim options are available only to &'trusted users'& and others are
2614 available only to &'admin users'&. In the description below, the phrases &"Exim
2615 user"& and &"Exim group"& mean the user and group defined by EXIM_USER and
2616 EXIM_GROUP in &_Local/Makefile_& or set by the &%exim_user%& and
2617 &%exim_group%& options. These do not necessarily have to use the name &"exim"&.
2619 .ilist
2620 .cindex "trusted users" "definition of"
2621 .cindex "user" "trusted definition of"
2622 The trusted users are root, the Exim user, any user listed in the
2623 &%trusted_users%& configuration option, and any user whose current group or any
2624 supplementary group is one of those listed in the &%trusted_groups%&
2625 configuration option. Note that the Exim group is not automatically trusted.
2627 .cindex '&"From"& line'
2628 .cindex "envelope sender"
2629 Trusted users are always permitted to use the &%-f%& option or a leading
2630 &"From&~"& line to specify the envelope sender of a message that is passed to
2631 Exim through the local interface (see the &%-bm%& and &%-f%& options below).
2632 See the &%untrusted_set_sender%& option for a way of permitting non-trusted
2633 users to set envelope senders.
2635 .cindex "&'From:'& header line"
2636 .cindex "&'Sender:'& header line"
2637 For a trusted user, there is never any check on the contents of the &'From:'&
2638 header line, and a &'Sender:'& line is never added. Furthermore, any existing
2639 &'Sender:'& line in incoming local (non-TCP/IP) messages is not removed.
2641 Trusted users may also specify a host name, host address, interface address,
2642 protocol name, ident value, and authentication data when submitting a message
2643 locally. Thus, they are able to insert messages into Exim's queue locally that
2644 have the characteristics of messages received from a remote host. Untrusted
2645 users may in some circumstances use &%-f%&, but can never set the other values
2646 that are available to trusted users.
2647 .next
2648 .cindex "user" "admin definition of"
2649 .cindex "admin user" "definition of"
2650 The admin users are root, the Exim user, and any user that is a member of the
2651 Exim group or of any group listed in the &%admin_groups%& configuration option.
2652 The current group does not have to be one of these groups.
2654 Admin users are permitted to list the queue, and to carry out certain
2655 operations on messages, for example, to force delivery failures. It is also
2656 necessary to be an admin user in order to see the full information provided by
2657 the Exim monitor, and full debugging output.
2659 By default, the use of the &%-M%&, &%-q%&, &%-R%&, and &%-S%& options to cause
2660 Exim to attempt delivery of messages on its queue is restricted to admin users.
2661 However, this restriction can be relaxed by setting the &%prod_requires_admin%&
2662 option false (that is, specifying &%no_prod_requires_admin%&).
2664 Similarly, the use of the &%-bp%& option to list all the messages in the queue
2665 is restricted to admin users unless &%queue_list_requires_admin%& is set
2666 false.
2667 .endlist
2670 &*Warning*&: If you configure your system so that admin users are able to
2671 edit Exim's configuration file, you are giving those users an easy way of
2672 getting root. There is further discussion of this issue at the start of chapter
2673 &<<CHAPconf>>&.
2678 .section "Command line options" "SECID39"
2679 Exim's command line options are described in alphabetical order below. If none
2680 of the options that specifies a specific action (such as starting the daemon or
2681 a queue runner, or testing an address, or receiving a message in a specific
2682 format, or listing the queue) are present, and there is at least one argument
2683 on the command line, &%-bm%& (accept a local message on the standard input,
2684 with the arguments specifying the recipients) is assumed. Otherwise, Exim
2685 outputs a brief message about itself and exits.
2687 . ////////////////////////////////////////////////////////////////////////////
2688 . Insert a stylized XML comment here, to identify the start of the command line
2689 . options. This is for the benefit of the Perl script that automatically
2690 . creates a man page for the options.
2691 . ////////////////////////////////////////////////////////////////////////////
2693 .literal xml
2694 <!-- === Start of command line options === -->
2695 .literal off
2698 .vlist
2699 .vitem &%--%&
2700 .oindex "--"
2701 .cindex "options" "command line; terminating"
2702 This is a pseudo-option whose only purpose is to terminate the options and
2703 therefore to cause subsequent command line items to be treated as arguments
2704 rather than options, even if they begin with hyphens.
2706 .vitem &%--help%&
2707 .oindex "&%--help%&"
2708 This option causes Exim to output a few sentences stating what it is.
2709 The same output is generated if the Exim binary is called with no options and
2710 no arguments.
2712 .vitem &%--version%&
2713 .oindex "&%--version%&"
2714 This option is an alias for &%-bV%& and causes version information to be
2715 displayed.
2717 .new
2718 .vitem &%-Ac%& &&&
2719 &%-Am%&
2720 .oindex "&%-Ac%&"
2721 .oindex "&%-Am%&"
2722 These options are used by Sendmail for selecting configuration files and are
2723 ignored by Exim.
2724 .wen
2726 .vitem &%-B%&<&'type'&>
2727 .oindex "&%-B%&"
2728 .cindex "8-bit characters"
2729 .cindex "Sendmail compatibility" "8-bit characters"
2730 This is a Sendmail option for selecting 7 or 8 bit processing. Exim is 8-bit
2731 clean; it ignores this option.
2733 .vitem &%-bd%&
2734 .oindex "&%-bd%&"
2735 .cindex "daemon"
2736 .cindex "SMTP" "listener"
2737 .cindex "queue runner"
2738 This option runs Exim as a daemon, awaiting incoming SMTP connections. Usually
2739 the &%-bd%& option is combined with the &%-q%&<&'time'&> option, to specify
2740 that the daemon should also initiate periodic queue runs.
2742 The &%-bd%& option can be used only by an admin user. If either of the &%-d%&
2743 (debugging) or &%-v%& (verifying) options are set, the daemon does not
2744 disconnect from the controlling terminal. When running this way, it can be
2745 stopped by pressing ctrl-C.
2747 By default, Exim listens for incoming connections to the standard SMTP port on
2748 all the host's running interfaces. However, it is possible to listen on other
2749 ports, on multiple ports, and only on specific interfaces. Chapter
2750 &<<CHAPinterfaces>>& contains a description of the options that control this.
2752 When a listening daemon
2753 .cindex "daemon" "process id (pid)"
2754 .cindex "pid (process id)" "of daemon"
2755 is started without the use of &%-oX%& (that is, without overriding the normal
2756 configuration), it writes its process id to a file called &_exim-daemon.pid_&
2757 in Exim's spool directory. This location can be overridden by setting
2758 PID_FILE_PATH in &_Local/Makefile_&. The file is written while Exim is still
2759 running as root.
2761 When &%-oX%& is used on the command line to start a listening daemon, the
2762 process id is not written to the normal pid file path. However, &%-oP%& can be
2763 used to specify a path on the command line if a pid file is required.
2765 The SIGHUP signal
2766 .cindex "SIGHUP"
2767 .cindex "daemon" "restarting"
2768 can be used to cause the daemon to re-execute itself. This should be done
2769 whenever Exim's configuration file, or any file that is incorporated into it by
2770 means of the &%.include%& facility, is changed, and also whenever a new version
2771 of Exim is installed. It is not necessary to do this when other files that are
2772 referenced from the configuration (for example, alias files) are changed,
2773 because these are reread each time they are used.
2775 .vitem &%-bdf%&
2776 .oindex "&%-bdf%&"
2777 This option has the same effect as &%-bd%& except that it never disconnects
2778 from the controlling terminal, even when no debugging is specified.
2780 .vitem &%-be%&
2781 .oindex "&%-be%&"
2782 .cindex "testing" "string expansion"
2783 .cindex "expansion" "testing"
2784 Run Exim in expansion testing mode. Exim discards its root privilege, to
2785 prevent ordinary users from using this mode to read otherwise inaccessible
2786 files. If no arguments are given, Exim runs interactively, prompting for lines
2787 of data. Otherwise, it processes each argument in turn.
2789 If Exim was built with USE_READLINE=yes in &_Local/Makefile_&, it tries
2790 to load the &%libreadline%& library dynamically whenever the &%-be%& option is
2791 used without command line arguments. If successful, it uses the &[readline()]&
2792 function, which provides extensive line-editing facilities, for reading the
2793 test data. A line history is supported.
2795 Long expansion expressions can be split over several lines by using backslash
2796 continuations. As in Exim's run time configuration, white space at the start of
2797 continuation lines is ignored. Each argument or data line is passed through the
2798 string expansion mechanism, and the result is output. Variable values from the
2799 configuration file (for example, &$qualify_domain$&) are available, but no
2800 message-specific values (such as &$sender_domain$&) are set, because no message
2801 is being processed (but see &%-bem%& and &%-Mset%&).
2803 &*Note*&: If you use this mechanism to test lookups, and you change the data
2804 files or databases you are using, you must exit and restart Exim before trying
2805 the same lookup again. Otherwise, because each Exim process caches the results
2806 of lookups, you will just get the same result as before.
2808 .vitem &%-bem%&&~<&'filename'&>
2809 .oindex "&%-bem%&"
2810 .cindex "testing" "string expansion"
2811 .cindex "expansion" "testing"
2812 This option operates like &%-be%& except that it must be followed by the name
2813 of a file. For example:
2814 .code
2815 exim -bem /tmp/testmessage
2816 .endd
2817 The file is read as a message (as if receiving a locally-submitted non-SMTP
2818 message) before any of the test expansions are done. Thus, message-specific
2819 variables such as &$message_size$& and &$header_from:$& are available. However,
2820 no &'Received:'& header is added to the message. If the &%-t%& option is set,
2821 recipients are read from the headers in the normal way, and are shown in the
2822 &$recipients$& variable. Note that recipients cannot be given on the command
2823 line, because further arguments are taken as strings to expand (just like
2824 &%-be%&).
2826 .vitem &%-bF%&&~<&'filename'&>
2827 .oindex "&%-bF%&"
2828 .cindex "system filter" "testing"
2829 .cindex "testing" "system filter"
2830 This option is the same as &%-bf%& except that it assumes that the filter being
2831 tested is a system filter. The additional commands that are available only in
2832 system filters are recognized.
2834 .vitem &%-bf%&&~<&'filename'&>
2835 .oindex "&%-bf%&"
2836 .cindex "filter" "testing"
2837 .cindex "testing" "filter file"
2838 .cindex "forward file" "testing"
2839 .cindex "testing" "forward file"
2840 .cindex "Sieve filter" "testing"
2841 This option runs Exim in user filter testing mode; the file is the filter file
2842 to be tested, and a test message must be supplied on the standard input. If
2843 there are no message-dependent tests in the filter, an empty file can be
2844 supplied.
2846 If you want to test a system filter file, use &%-bF%& instead of &%-bf%&. You
2847 can use both &%-bF%& and &%-bf%& on the same command, in order to test a system
2848 filter and a user filter in the same run. For example:
2849 .code
2850 exim -bF /system/filter -bf /user/filter </test/message
2851 .endd
2852 This is helpful when the system filter adds header lines or sets filter
2853 variables that are used by the user filter.
2855 If the test filter file does not begin with one of the special lines
2856 .code
2857 # Exim filter
2858 # Sieve filter
2859 .endd
2860 it is taken to be a normal &_.forward_& file, and is tested for validity under
2861 that interpretation. See sections &<<SECTitenonfilred>>& to
2862 &<<SECTspecitredli>>& for a description of the possible contents of non-filter
2863 redirection lists.
2865 The result of an Exim command that uses &%-bf%&, provided no errors are
2866 detected, is a list of the actions that Exim would try to take if presented
2867 with the message for real. More details of filter testing are given in the
2868 separate document entitled &'Exim's interfaces to mail filtering'&.
2870 When testing a filter file,
2871 .cindex "&""From""& line"
2872 .cindex "envelope sender"
2873 .oindex "&%-f%&" "for filter testing"
2874 the envelope sender can be set by the &%-f%& option,
2875 or by a &"From&~"& line at the start of the test message. Various parameters
2876 that would normally be taken from the envelope recipient address of the message
2877 can be set by means of additional command line options (see the next four
2878 options).
2880 .vitem &%-bfd%&&~<&'domain'&>
2881 .oindex "&%-bfd%&"
2882 .vindex "&$qualify_domain$&"
2883 This sets the domain of the recipient address when a filter file is being
2884 tested by means of the &%-bf%& option. The default is the value of
2885 &$qualify_domain$&.
2887 .vitem &%-bfl%&&~<&'local&~part'&>
2888 .oindex "&%-bfl%&"
2889 This sets the local part of the recipient address when a filter file is being
2890 tested by means of the &%-bf%& option. The default is the username of the
2891 process that calls Exim. A local part should be specified with any prefix or
2892 suffix stripped, because that is how it appears to the filter when a message is
2893 actually being delivered.
2895 .vitem &%-bfp%&&~<&'prefix'&>
2896 .oindex "&%-bfp%&"
2897 This sets the prefix of the local part of the recipient address when a filter
2898 file is being tested by means of the &%-bf%& option. The default is an empty
2899 prefix.
2901 .vitem &%-bfs%&&~<&'suffix'&>
2902 .oindex "&%-bfs%&"
2903 This sets the suffix of the local part of the recipient address when a filter
2904 file is being tested by means of the &%-bf%& option. The default is an empty
2905 suffix.
2907 .vitem &%-bh%&&~<&'IP&~address'&>
2908 .oindex "&%-bh%&"
2909 .cindex "testing" "incoming SMTP"
2910 .cindex "SMTP" "testing incoming"
2911 .cindex "testing" "relay control"
2912 .cindex "relaying" "testing configuration"
2913 .cindex "policy control" "testing"
2914 .cindex "debugging" "&%-bh%& option"
2915 This option runs a fake SMTP session as if from the given IP address, using the
2916 standard input and output. The IP address may include a port number at the end,
2917 after a full stop. For example:
2918 .code
2919 exim -bh
2920 exim -bh fe80::a00:20ff:fe86:a061.5678
2921 .endd
2922 When an IPv6 address is given, it is converted into canonical form. In the case
2923 of the second example above, the value of &$sender_host_address$& after
2924 conversion to the canonical form is
2925 &`fe80:0000:0000:0a00:20ff:fe86:a061.5678`&.
2927 Comments as to what is going on are written to the standard error file. These
2928 include lines beginning with &"LOG"& for anything that would have been logged.
2929 This facility is provided for testing configuration options for incoming
2930 messages, to make sure they implement the required policy. For example, you can
2931 test your relay controls using &%-bh%&.
2933 &*Warning 1*&:
2934 .cindex "RFC 1413"
2935 You can test features of the configuration that rely on ident (RFC 1413)
2936 information by using the &%-oMt%& option. However, Exim cannot actually perform
2937 an ident callout when testing using &%-bh%& because there is no incoming SMTP
2938 connection.
2940 &*Warning 2*&: Address verification callouts (see section &<<SECTcallver>>&)
2941 are also skipped when testing using &%-bh%&. If you want these callouts to
2942 occur, use &%-bhc%& instead.
2944 Messages supplied during the testing session are discarded, and nothing is
2945 written to any of the real log files. There may be pauses when DNS (and other)
2946 lookups are taking place, and of course these may time out. The &%-oMi%& option
2947 can be used to specify a specific IP interface and port if this is important,
2948 and &%-oMaa%& and &%-oMai%& can be used to set parameters as if the SMTP
2949 session were authenticated.
2951 The &'exim_checkaccess'& utility is a &"packaged"& version of &%-bh%& whose
2952 output just states whether a given recipient address from a given host is
2953 acceptable or not. See section &<<SECTcheckaccess>>&.
2955 Features such as authentication and encryption, where the client input is not
2956 plain text, cannot easily be tested with &%-bh%&. Instead, you should use a
2957 specialized SMTP test program such as
2958 &url(,swaks).
2960 .vitem &%-bhc%&&~<&'IP&~address'&>
2961 .oindex "&%-bhc%&"
2962 This option operates in the same way as &%-bh%&, except that address
2963 verification callouts are performed if required. This includes consulting and
2964 updating the callout cache database.
2966 .vitem &%-bi%&
2967 .oindex "&%-bi%&"
2968 .cindex "alias file" "building"
2969 .cindex "building alias file"
2970 .cindex "Sendmail compatibility" "&%-bi%& option"
2971 Sendmail interprets the &%-bi%& option as a request to rebuild its alias file.
2972 Exim does not have the concept of a single alias file, and so it cannot mimic
2973 this behaviour. However, calls to &_/usr/lib/sendmail_& with the &%-bi%& option
2974 tend to appear in various scripts such as NIS make files, so the option must be
2975 recognized.
2977 If &%-bi%& is encountered, the command specified by the &%bi_command%&
2978 configuration option is run, under the uid and gid of the caller of Exim. If
2979 the &%-oA%& option is used, its value is passed to the command as an argument.
2980 The command set by &%bi_command%& may not contain arguments. The command can
2981 use the &'exim_dbmbuild'& utility, or some other means, to rebuild alias files
2982 if this is required. If the &%bi_command%& option is not set, calling Exim with
2983 &%-bi%& is a no-op.
2985 .new
2986 . // Keep :help first, then the rest in alphabetical order
2987 .vitem &%-bI:help%&
2988 .oindex "&%-bI:help%&"
2989 .cindex "querying exim information"
2990 We shall provide various options starting &`-bI:`& for querying Exim for
2991 information. The output of many of these will be intended for machine
2992 consumption. This one is not. The &%-bI:help%& option asks Exim for a
2993 synopsis of supported options beginning &`-bI:`&. Use of any of these
2994 options shall cause Exim to exit after producing the requested output.
2996 .vitem &%-bI:dscp%&
2997 .oindex "&%-bI:dscp%&"
2998 .cindex "DSCP" "values"
2999 This option causes Exim to emit an alphabetically sorted list of all
3000 recognised DSCP names.
3002 .vitem &%-bI:sieve%&
3003 .oindex "&%-bI:sieve%&"
3004 .cindex "Sieve filter" "capabilities"
3005 This option causes Exim to emit an alphabetically sorted list of all supported
3006 Sieve protocol extensions on stdout, one per line. This is anticipated to be
3007 useful for ManageSieve (RFC 5804) implementations, in providing that protocol's
3008 &`SIEVE`& capability response line. As the precise list may depend upon
3009 compile-time build options, which this option will adapt to, this is the only
3010 way to guarantee a correct response.
3011 .wen
3013 .vitem &%-bm%&
3014 .oindex "&%-bm%&"
3015 .cindex "local message reception"
3016 This option runs an Exim receiving process that accepts an incoming,
3017 locally-generated message on the standard input. The recipients are given as the
3018 command arguments (except when &%-t%& is also present &-- see below). Each
3019 argument can be a comma-separated list of RFC 2822 addresses. This is the
3020 default option for selecting the overall action of an Exim call; it is assumed
3021 if no other conflicting option is present.
3023 If any addresses in the message are unqualified (have no domain), they are
3024 qualified by the values of the &%qualify_domain%& or &%qualify_recipient%&
3025 options, as appropriate. The &%-bnq%& option (see below) provides a way of
3026 suppressing this for special cases.
3028 Policy checks on the contents of local messages can be enforced by means of
3029 the non-SMTP ACL. See chapter &<<CHAPACL>>& for details.
3031 .cindex "return code" "for &%-bm%&"
3032 The return code is zero if the message is successfully accepted. Otherwise, the
3033 action is controlled by the &%-oe%&&'x'& option setting &-- see below.
3035 The format
3036 .cindex "message" "format"
3037 .cindex "format" "message"
3038 .cindex "&""From""& line"
3039 .cindex "UUCP" "&""From""& line"
3040 .cindex "Sendmail compatibility" "&""From""& line"
3041 of the message must be as defined in RFC 2822, except that, for
3042 compatibility with Sendmail and Smail, a line in one of the forms
3043 .code
3044 From sender Fri Jan 5 12:55 GMT 1997
3045 From sender Fri, 5 Jan 97 12:55:01
3046 .endd
3047 (with the weekday optional, and possibly with additional text after the date)
3048 is permitted to appear at the start of the message. There appears to be no
3049 authoritative specification of the format of this line. Exim recognizes it by
3050 matching against the regular expression defined by the &%uucp_from_pattern%&
3051 option, which can be changed if necessary.
3053 .oindex "&%-f%&" "overriding &""From""& line"
3054 The specified sender is treated as if it were given as the argument to the
3055 &%-f%& option, but if a &%-f%& option is also present, its argument is used in
3056 preference to the address taken from the message. The caller of Exim must be a
3057 trusted user for the sender of a message to be set in this way.
3059 .vitem &%-bmalware%&&~<&'filename'&>
3060 .oindex "&%-bmalware%&"
3061 .cindex "testing", "malware"
3062 .cindex "malware scan test"
3063 This debugging option causes Exim to scan the given file,
3064 using the malware scanning framework. The option of &%av_scanner%& influences
3065 this option, so if &%av_scanner%&'s value is dependent upon an expansion then
3066 the expansion should have defaults which apply to this invocation. ACLs are
3067 not invoked, so if &%av_scanner%& references an ACL variable then that variable
3068 will never be populated and &%-bmalware%& will fail.
3070 Exim will have changed working directory before resolving the filename, so
3071 using fully qualified pathnames is advisable. Exim will be running as the Exim
3072 user when it tries to open the file, rather than as the invoking user.
3073 This option requires admin privileges.
3075 The &%-bmalware%& option will not be extended to be more generally useful,
3076 there are better tools for file-scanning. This option exists to help
3077 administrators verify their Exim and AV scanner configuration.
3079 .vitem &%-bnq%&
3080 .oindex "&%-bnq%&"
3081 .cindex "address qualification, suppressing"
3082 By default, Exim automatically qualifies unqualified addresses (those
3083 without domains) that appear in messages that are submitted locally (that
3084 is, not over TCP/IP). This qualification applies both to addresses in
3085 envelopes, and addresses in header lines. Sender addresses are qualified using
3086 &%qualify_domain%&, and recipient addresses using &%qualify_recipient%& (which
3087 defaults to the value of &%qualify_domain%&).
3089 Sometimes, qualification is not wanted. For example, if &%-bS%& (batch SMTP) is
3090 being used to re-submit messages that originally came from remote hosts after
3091 content scanning, you probably do not want to qualify unqualified addresses in
3092 header lines. (Such lines will be present only if you have not enabled a header
3093 syntax check in the appropriate ACL.)
3095 The &%-bnq%& option suppresses all qualification of unqualified addresses in
3096 messages that originate on the local host. When this is used, unqualified
3097 addresses in the envelope provoke errors (causing message rejection) and
3098 unqualified addresses in header lines are left alone.
3101 .vitem &%-bP%&
3102 .oindex "&%-bP%&"
3103 .cindex "configuration options" "extracting"
3104 .cindex "options" "configuration &-- extracting"
3105 If this option is given with no arguments, it causes the values of all Exim's
3106 main configuration options to be written to the standard output. The values
3107 of one or more specific options can be requested by giving their names as
3108 arguments, for example:
3109 .code
3110 exim -bP qualify_domain hold_domains
3111 .endd
3112 .cindex "hiding configuration option values"
3113 .cindex "configuration options" "hiding value of"
3114 .cindex "options" "hiding value of"
3115 However, any option setting that is preceded by the word &"hide"& in the
3116 configuration file is not shown in full, except to an admin user. For other
3117 users, the output is as in this example:
3118 .code
3119 mysql_servers = <value not displayable>
3120 .endd
3121 If &%configure_file%& is given as an argument, the name of the run time
3122 configuration file is output.
3123 If a list of configuration files was supplied, the value that is output here
3124 is the name of the file that was actually used.
3126 .new
3127 .cindex "options" "hiding name of"
3128 If the &%-n%& flag is given, then for most modes of &%-bP%& operation the
3129 name will not be output.
3130 .wen
3132 .cindex "daemon" "process id (pid)"
3133 .cindex "pid (process id)" "of daemon"
3134 If &%log_file_path%& or &%pid_file_path%& are given, the names of the
3135 directories where log files and daemon pid files are written are output,
3136 respectively. If these values are unset, log files are written in a
3137 sub-directory of the spool directory called &%log%&, and the pid file is
3138 written directly into the spool directory.
3140 If &%-bP%& is followed by a name preceded by &`+`&, for example,
3141 .code
3142 exim -bP +local_domains
3143 .endd
3144 it searches for a matching named list of any type (domain, host, address, or
3145 local part) and outputs what it finds.
3147 .cindex "options" "router &-- extracting"
3148 .cindex "options" "transport &-- extracting"
3149 .cindex "options" "authenticator &-- extracting"
3150 If one of the words &%router%&, &%transport%&, or &%authenticator%& is given,
3151 followed by the name of an appropriate driver instance, the option settings for
3152 that driver are output. For example:
3153 .code
3154 exim -bP transport local_delivery
3155 .endd
3156 The generic driver options are output first, followed by the driver's private
3157 options. A list of the names of drivers of a particular type can be obtained by
3158 using one of the words &%router_list%&, &%transport_list%&, or
3159 &%authenticator_list%&, and a complete list of all drivers with their option
3160 settings can be obtained by using &%routers%&, &%transports%&, or
3161 &%authenticators%&.
3163 .cindex "options" "macro &-- extracting"
3164 If invoked by an admin user, then &%macro%&, &%macro_list%& and &%macros%&
3165 are available, similarly to the drivers. Because macros are sometimes used
3166 for storing passwords, this option is restricted.
3167 The output format is one item per line.
3169 .vitem &%-bp%&
3170 .oindex "&%-bp%&"
3171 .cindex "queue" "listing messages on"
3172 .cindex "listing" "messages on the queue"
3173 This option requests a listing of the contents of the mail queue on the
3174 standard output. If the &%-bp%& option is followed by a list of message ids,
3175 just those messages are listed. By default, this option can be used only by an
3176 admin user. However, the &%queue_list_requires_admin%& option can be set false
3177 to allow any user to see the queue.
3179 Each message on the queue is displayed as in the following example:
3180 .code
3181 25m 2.9K 0t5C6f-0000c8-00 <alice@wonderland.fict.example>
3182 red.king@looking-glass.fict.example
3183 <other addresses>
3184 .endd
3185 .cindex "message" "size in queue listing"
3186 .cindex "size" "of message"
3187 The first line contains the length of time the message has been on the queue
3188 (in this case 25 minutes), the size of the message (2.9K), the unique local
3189 identifier for the message, and the message sender, as contained in the
3190 envelope. For bounce messages, the sender address is empty, and appears as
3191 &"<>"&. If the message was submitted locally by an untrusted user who overrode
3192 the default sender address, the user's login name is shown in parentheses
3193 before the sender address.
3195 .cindex "frozen messages" "in queue listing"
3196 If the message is frozen (attempts to deliver it are suspended) then the text
3197 &"*** frozen ***"& is displayed at the end of this line.
3199 The recipients of the message (taken from the envelope, not the headers) are
3200 displayed on subsequent lines. Those addresses to which the message has already
3201 been delivered are marked with the letter D. If an original address gets
3202 expanded into several addresses via an alias or forward file, the original is
3203 displayed with a D only when deliveries for all of its child addresses are
3204 complete.
3207 .vitem &%-bpa%&
3208 .oindex "&%-bpa%&"
3209 This option operates like &%-bp%&, but in addition it shows delivered addresses
3210 that were generated from the original top level address(es) in each message by
3211 alias or forwarding operations. These addresses are flagged with &"+D"& instead
3212 of just &"D"&.
3215 .vitem &%-bpc%&
3216 .oindex "&%-bpc%&"
3217 .cindex "queue" "count of messages on"
3218 This option counts the number of messages on the queue, and writes the total
3219 to the standard output. It is restricted to admin users, unless
3220 &%queue_list_requires_admin%& is set false.
3223 .vitem &%-bpr%&
3224 .oindex "&%-bpr%&"
3225 This option operates like &%-bp%&, but the output is not sorted into
3226 chronological order of message arrival. This can speed it up when there are
3227 lots of messages on the queue, and is particularly useful if the output is
3228 going to be post-processed in a way that doesn't need the sorting.
3230 .vitem &%-bpra%&
3231 .oindex "&%-bpra%&"
3232 This option is a combination of &%-bpr%& and &%-bpa%&.
3234 .vitem &%-bpru%&
3235 .oindex "&%-bpru%&"
3236 This option is a combination of &%-bpr%& and &%-bpu%&.
3239 .vitem &%-bpu%&
3240 .oindex "&%-bpu%&"
3241 This option operates like &%-bp%& but shows only undelivered top-level
3242 addresses for each message displayed. Addresses generated by aliasing or
3243 forwarding are not shown, unless the message was deferred after processing by a
3244 router with the &%one_time%& option set.
3247 .vitem &%-brt%&
3248 .oindex "&%-brt%&"
3249 .cindex "testing" "retry configuration"
3250 .cindex "retry" "configuration testing"
3251 This option is for testing retry rules, and it must be followed by up to three
3252 arguments. It causes Exim to look for a retry rule that matches the values
3253 and to write it to the standard output. For example:
3254 .code
3255 exim -brt bach.comp.mus.example
3256 Retry rule: *.comp.mus.example F,2h,15m; F,4d,30m;
3257 .endd
3258 See chapter &<<CHAPretry>>& for a description of Exim's retry rules. The first
3259 argument, which is required, can be a complete address in the form
3260 &'local_part@domain'&, or it can be just a domain name. If the second argument
3261 contains a dot, it is interpreted as an optional second domain name; if no
3262 retry rule is found for the first argument, the second is tried. This ties in
3263 with Exim's behaviour when looking for retry rules for remote hosts &-- if no
3264 rule is found that matches the host, one that matches the mail domain is
3265 sought. Finally, an argument that is the name of a specific delivery error, as
3266 used in setting up retry rules, can be given. For example:
3267 .code
3268 exim -brt haydn.comp.mus.example quota_3d
3269 Retry rule: *@haydn.comp.mus.example quota_3d F,1h,15m
3270 .endd
3272 .vitem &%-brw%&
3273 .oindex "&%-brw%&"
3274 .cindex "testing" "rewriting"
3275 .cindex "rewriting" "testing"
3276 This option is for testing address rewriting rules, and it must be followed by
3277 a single argument, consisting of either a local part without a domain, or a
3278 complete address with a fully qualified domain. Exim outputs how this address
3279 would be rewritten for each possible place it might appear. See chapter
3280 &<<CHAPrewrite>>& for further details.
3282 .vitem &%-bS%&
3283 .oindex "&%-bS%&"
3284 .cindex "SMTP" "batched incoming"
3285 .cindex "batched SMTP input"
3286 This option is used for batched SMTP input, which is an alternative interface
3287 for non-interactive local message submission. A number of messages can be
3288 submitted in a single run. However, despite its name, this is not really SMTP
3289 input. Exim reads each message's envelope from SMTP commands on the standard
3290 input, but generates no responses. If the caller is trusted, or
3291 &%untrusted_set_sender%& is set, the senders in the SMTP MAIL commands are
3292 believed; otherwise the sender is always the caller of Exim.
3294 The message itself is read from the standard input, in SMTP format (leading
3295 dots doubled), terminated by a line containing just a single dot. An error is
3296 provoked if the terminating dot is missing. A further message may then follow.
3298 As for other local message submissions, the contents of incoming batch SMTP
3299 messages can be checked using the non-SMTP ACL (see chapter &<<CHAPACL>>&).
3300 Unqualified addresses are automatically qualified using &%qualify_domain%& and
3301 &%qualify_recipient%&, as appropriate, unless the &%-bnq%& option is used.
3303 Some other SMTP commands are recognized in the input. HELO and EHLO act
3304 as RSET; VRFY, EXPN, ETRN, and HELP act as NOOP;
3305 QUIT quits, ignoring the rest of the standard input.
3307 .cindex "return code" "for &%-bS%&"
3308 If any error is encountered, reports are written to the standard output and
3309 error streams, and Exim gives up immediately. The return code is 0 if no error
3310 was detected; it is 1 if one or more messages were accepted before the error
3311 was detected; otherwise it is 2.
3313 More details of input using batched SMTP are given in section
3314 &<<SECTincomingbatchedSMTP>>&.
3316 .vitem &%-bs%&
3317 .oindex "&%-bs%&"
3318 .cindex "SMTP" "local input"
3319 .cindex "local SMTP input"
3320 This option causes Exim to accept one or more messages by reading SMTP commands
3321 on the standard input, and producing SMTP replies on the standard output. SMTP
3322 policy controls, as defined in ACLs (see chapter &<<CHAPACL>>&) are applied.
3323 Some user agents use this interface as a way of passing locally-generated
3324 messages to the MTA.
3326 In
3327 .cindex "sender" "source of"
3328 this usage, if the caller of Exim is trusted, or &%untrusted_set_sender%& is
3329 set, the senders of messages are taken from the SMTP MAIL commands.
3330 Otherwise the content of these commands is ignored and the sender is set up as
3331 the calling user. Unqualified addresses are automatically qualified using
3332 &%qualify_domain%& and &%qualify_recipient%&, as appropriate, unless the
3333 &%-bnq%& option is used.
3335 .cindex "inetd"
3336 The
3337 &%-bs%& option is also used to run Exim from &'inetd'&, as an alternative to
3338 using a listening daemon. Exim can distinguish the two cases by checking
3339 whether the standard input is a TCP/IP socket. When Exim is called from
3340 &'inetd'&, the source of the mail is assumed to be remote, and the comments
3341 above concerning senders and qualification do not apply. In this situation,
3342 Exim behaves in exactly the same way as it does when receiving a message via
3343 the listening daemon.
3345 .vitem &%-bt%&
3346 .oindex "&%-bt%&"
3347 .cindex "testing" "addresses"
3348 .cindex "address" "testing"
3349 This option runs Exim in address testing mode, in which each argument is taken
3350 as a recipient address to be tested for deliverability. The results are
3351 written to the standard output. If a test fails, and the caller is not an admin
3352 user, no details of the failure are output, because these might contain
3353 sensitive information such as usernames and passwords for database lookups.
3355 If no arguments are given, Exim runs in an interactive manner, prompting with a
3356 right angle bracket for addresses to be tested.
3358 Unlike the &%-be%& test option, you cannot arrange for Exim to use the
3359 &[readline()]& function, because it is running as &'root'& and there are
3360 security issues.
3362 Each address is handled as if it were the recipient address of a message
3363 (compare the &%-bv%& option). It is passed to the routers and the result is
3364 written to the standard output. However, any router that has
3365 &%no_address_test%& set is bypassed. This can make &%-bt%& easier to use for
3366 genuine routing tests if your first router passes everything to a scanner
3367 program.
3369 .cindex "return code" "for &%-bt%&"
3370 The return code is 2 if any address failed outright; it is 1 if no address
3371 failed outright but at least one could not be resolved for some reason. Return
3372 code 0 is given only when all addresses succeed.
3374 .cindex "duplicate addresses"
3375 &*Note*&: When actually delivering a message, Exim removes duplicate recipient
3376 addresses after routing is complete, so that only one delivery takes place.
3377 This does not happen when testing with &%-bt%&; the full results of routing are
3378 always shown.
3380 &*Warning*&: &%-bt%& can only do relatively simple testing. If any of the
3381 routers in the configuration makes any tests on the sender address of a
3382 message,
3383 .oindex "&%-f%&" "for address testing"
3384 you can use the &%-f%& option to set an appropriate sender when running
3385 &%-bt%& tests. Without it, the sender is assumed to be the calling user at the
3386 default qualifying domain. However, if you have set up (for example) routers
3387 whose behaviour depends on the contents of an incoming message, you cannot test
3388 those conditions using &%-bt%&. The &%-N%& option provides a possible way of
3389 doing such tests.
3391 .vitem &%-bV%&
3392 .oindex "&%-bV%&"
3393 .cindex "version number of Exim"
3394 This option causes Exim to write the current version number, compilation
3395 number, and compilation date of the &'exim'& binary to the standard output.
3396 It also lists the DBM library that is being used, the optional modules (such as
3397 specific lookup types), the drivers that are included in the binary, and the
3398 name of the run time configuration file that is in use.
3400 As part of its operation, &%-bV%& causes Exim to read and syntax check its
3401 configuration file. However, this is a static check only. It cannot check
3402 values that are to be expanded. For example, although a misspelt ACL verb is
3403 detected, an error in the verb's arguments is not. You cannot rely on &%-bV%&
3404 alone to discover (for example) all the typos in the configuration; some
3405 realistic testing is needed. The &%-bh%& and &%-N%& options provide more
3406 dynamic testing facilities.
3408 .vitem &%-bv%&
3409 .oindex "&%-bv%&"
3410 .cindex "verifying address" "using &%-bv%&"
3411 .cindex "address" "verification"
3412 This option runs Exim in address verification mode, in which each argument is
3413 taken as a recipient address to be verified by the routers. (This does
3414 not involve any verification callouts). During normal operation, verification
3415 happens mostly as a consequence processing a &%verify%& condition in an ACL
3416 (see chapter &<<CHAPACL>>&). If you want to test an entire ACL, possibly
3417 including callouts, see the &%-bh%& and &%-bhc%& options.
3419 If verification fails, and the caller is not an admin user, no details of the
3420 failure are output, because these might contain sensitive information such as
3421 usernames and passwords for database lookups.
3423 If no arguments are given, Exim runs in an interactive manner, prompting with a
3424 right angle bracket for addresses to be verified.
3426 Unlike the &%-be%& test option, you cannot arrange for Exim to use the
3427 &[readline()]& function, because it is running as &'exim'& and there are
3428 security issues.
3430 Verification differs from address testing (the &%-bt%& option) in that routers
3431 that have &%no_verify%& set are skipped, and if the address is accepted by a
3432 router that has &%fail_verify%& set, verification fails. The address is
3433 verified as a recipient if &%-bv%& is used; to test verification for a sender
3434 address, &%-bvs%& should be used.
3436 If the &%-v%& option is not set, the output consists of a single line for each
3437 address, stating whether it was verified or not, and giving a reason in the
3438 latter case. Without &%-v%&, generating more than one address by redirection
3439 causes verification to end successfully, without considering the generated
3440 addresses. However, if just one address is generated, processing continues,
3441 and the generated address must verify successfully for the overall verification
3442 to succeed.
3444 When &%-v%& is set, more details are given of how the address has been handled,
3445 and in the case of address redirection, all the generated addresses are also
3446 considered. Verification may succeed for some and fail for others.
3448 The
3449 .cindex "return code" "for &%-bv%&"
3450 return code is 2 if any address failed outright; it is 1 if no address
3451 failed outright but at least one could not be resolved for some reason. Return
3452 code 0 is given only when all addresses succeed.
3454 If any of the routers in the configuration makes any tests on the sender
3455 address of a message, you should use the &%-f%& option to set an appropriate
3456 sender when running &%-bv%& tests. Without it, the sender is assumed to be the
3457 calling user at the default qualifying domain.
3459 .vitem &%-bvs%&
3460 .oindex "&%-bvs%&"
3461 This option acts like &%-bv%&, but verifies the address as a sender rather
3462 than a recipient address. This affects any rewriting and qualification that
3463 might happen.
3465 .vitem &%-bw%&
3466 .oindex "&%-bw%&"
3467 .cindex "daemon"
3468 .cindex "inetd"
3469 .cindex "inetd" "wait mode"
3470 This option runs Exim as a daemon, awaiting incoming SMTP connections,
3471 similarly to the &%-bd%& option. All port specifications on the command-line
3472 and in the configuration file are ignored. Queue-running may not be specified.
3474 In this mode, Exim expects to be passed a socket as fd 0 (stdin) which is
3475 listening for connections. This permits the system to start up and have
3476 inetd (or equivalent) listen on the SMTP ports, starting an Exim daemon for
3477 each port only when the first connection is received.
3479 If the option is given as &%-bw%&<&'time'&> then the time is a timeout, after
3480 which the daemon will exit, which should cause inetd to listen once more.
3482 .vitem &%-C%&&~<&'filelist'&>
3483 .oindex "&%-C%&"
3484 .cindex "configuration file" "alternate"
3485 .cindex "CONFIGURE_FILE"
3486 .cindex "alternate configuration file"
3487 This option causes Exim to find the run time configuration file from the given
3488 list instead of from the list specified by the CONFIGURE_FILE
3489 compile-time setting. Usually, the list will consist of just a single file
3490 name, but it can be a colon-separated list of names. In this case, the first
3491 file that exists is used. Failure to open an existing file stops Exim from
3492 proceeding any further along the list, and an error is generated.
3494 When this option is used by a caller other than root, and the list is different
3495 from the compiled-in list, Exim gives up its root privilege immediately, and
3496 runs with the real and effective uid and gid set to those of the caller.
3497 However, if a TRUSTED_CONFIG_LIST file is defined in &_Local/Makefile_&, that
3498 file contains a list of full pathnames, one per line, for configuration files
3499 which are trusted. Root privilege is retained for any configuration file so
3500 listed, as long as the caller is the Exim user (or the user specified in the
3501 CONFIGURE_OWNER option, if any), and as long as the configuration file is
3502 not writeable by inappropriate users or groups.
3504 Leaving TRUSTED_CONFIG_LIST unset precludes the possibility of testing a
3505 configuration using &%-C%& right through message reception and delivery,
3506 even if the caller is root. The reception works, but by that time, Exim is
3507 running as the Exim user, so when it re-executes to regain privilege for the
3508 delivery, the use of &%-C%& causes privilege to be lost. However, root can
3509 test reception and delivery using two separate commands (one to put a message
3510 on the queue, using &%-odq%&, and another to do the delivery, using &%-M%&).
3512 If ALT_CONFIG_PREFIX is defined &_in Local/Makefile_&, it specifies a
3513 prefix string with which any file named in a &%-C%& command line option
3514 must start. In addition, the file name must not contain the sequence &`/../`&.
3515 However, if the value of the &%-C%& option is identical to the value of
3516 CONFIGURE_FILE in &_Local/Makefile_&, Exim ignores &%-C%& and proceeds as
3517 usual. There is no default setting for ALT_CONFIG_PREFIX; when it is
3518 unset, any file name can be used with &%-C%&.
3520 ALT_CONFIG_PREFIX can be used to confine alternative configuration files
3521 to a directory to which only root has access. This prevents someone who has
3522 broken into the Exim account from running a privileged Exim with an arbitrary
3523 configuration file.
3525 The &%-C%& facility is useful for ensuring that configuration files are
3526 syntactically correct, but cannot be used for test deliveries, unless the
3527 caller is privileged, or unless it is an exotic configuration that does not
3528 require privilege. No check is made on the owner or group of the files
3529 specified by this option.
3532 .vitem &%-D%&<&'macro'&>=<&'value'&>
3533 .oindex "&%-D%&"
3534 .cindex "macro" "setting on command line"
3535 This option can be used to override macro definitions in the configuration file
3536 (see section &<<SECTmacrodefs>>&). However, like &%-C%&, if it is used by an
3537 unprivileged caller, it causes Exim to give up its root privilege.
3538 If DISABLE_D_OPTION is defined in &_Local/Makefile_&, the use of &%-D%& is
3539 completely disabled, and its use causes an immediate error exit.
3541 If WHITELIST_D_MACROS is defined in &_Local/Makefile_& then it should be a
3542 colon-separated list of macros which are considered safe and, if &%-D%& only
3543 supplies macros from this list, and the values are acceptable, then Exim will
3544 not give up root privilege if the caller is root, the Exim run-time user, or
3545 the CONFIGURE_OWNER, if set. This is a transition mechanism and is expected
3546 to be removed in the future. Acceptable values for the macros satisfy the
3547 regexp: &`^[A-Za-z0-9_/.-]*$`&
3549 The entire option (including equals sign if present) must all be within one
3550 command line item. &%-D%& can be used to set the value of a macro to the empty
3551 string, in which case the equals sign is optional. These two commands are
3552 synonymous:
3553 .code
3554 exim -DABC ...
3555 exim -DABC= ...
3556 .endd
3557 To include spaces in a macro definition item, quotes must be used. If you use
3558 quotes, spaces are permitted around the macro name and the equals sign. For
3559 example:
3560 .code
3561 exim '-D ABC = something' ...
3562 .endd
3563 &%-D%& may be repeated up to 10 times on a command line.
3566 .vitem &%-d%&<&'debug&~options'&>
3567 .oindex "&%-d%&"
3568 .cindex "debugging" "list of selectors"
3569 .cindex "debugging" "&%-d%& option"
3570 This option causes debugging information to be written to the standard
3571 error stream. It is restricted to admin users because debugging output may show
3572 database queries that contain password information. Also, the details of users'
3573 filter files should be protected. If a non-admin user uses &%-d%&, Exim
3574 writes an error message to the standard error stream and exits with a non-zero
3575 return code.
3577 When &%-d%& is used, &%-v%& is assumed. If &%-d%& is given on its own, a lot of
3578 standard debugging data is output. This can be reduced, or increased to include
3579 some more rarely needed information, by directly following &%-d%& with a string
3580 made up of names preceded by plus or minus characters. These add or remove sets
3581 of debugging data, respectively. For example, &%-d+filter%& adds filter
3582 debugging, whereas &%-d-all+filter%& selects only filter debugging. Note that
3583 no spaces are allowed in the debug setting. The available debugging categories
3584 are:
3585 .display
3586 &`acl `& ACL interpretation
3587 &`auth `& authenticators
3588 &`deliver `& general delivery logic
3589 &`dns `& DNS lookups (see also resolver)
3590 &`dnsbl `& DNS black list (aka RBL) code
3591 &`exec `& arguments for &[execv()]& calls
3592 &`expand `& detailed debugging for string expansions
3593 &`filter `& filter handling
3594 &`hints_lookup `& hints data lookups
3595 &`host_lookup `& all types of name-to-IP address handling
3596 &`ident `& ident lookup
3597 &`interface `& lists of local interfaces
3598 &`lists `& matching things in lists
3599 &`load `& system load checks
3600 &`local_scan `& can be used by &[local_scan()]& (see chapter &&&
3601 &<<CHAPlocalscan>>&)
3602 &`lookup `& general lookup code and all lookups
3603 &`memory `& memory handling
3604 &`pid `& add pid to debug output lines
3605 &`process_info `& setting info for the process log
3606 &`queue_run `& queue runs
3607 &`receive `& general message reception logic
3608 &`resolver `& turn on the DNS resolver's debugging output
3609 &`retry `& retry handling
3610 &`rewrite `& address rewriting
3611 &`route `& address routing
3612 &`timestamp `& add timestamp to debug output lines
3613 &`tls `& TLS logic
3614 &`transport `& transports
3615 &`uid `& changes of uid/gid and looking up uid/gid
3616 &`verify `& address verification logic
3617 &`all `& almost all of the above (see below), and also &%-v%&
3618 .endd
3619 The &`all`& option excludes &`memory`& when used as &`+all`&, but includes it
3620 for &`-all`&. The reason for this is that &`+all`& is something that people
3621 tend to use when generating debug output for Exim maintainers. If &`+memory`&
3622 is included, an awful lot of output that is very rarely of interest is
3623 generated, so it now has to be explicitly requested. However, &`-all`& does
3624 turn everything off.
3626 .cindex "resolver, debugging output"
3627 .cindex "DNS resolver, debugging output"
3628 The &`resolver`& option produces output only if the DNS resolver was compiled
3629 with DEBUG enabled. This is not the case in some operating systems. Also,
3630 unfortunately, debugging output from the DNS resolver is written to stdout
3631 rather than stderr.
3633 The default (&%-d%& with no argument) omits &`expand`&, &`filter`&,
3634 &`interface`&, &`load`&, &`memory`&, &`pid`&, &`resolver`&, and &`timestamp`&.
3635 However, the &`pid`& selector is forced when debugging is turned on for a
3636 daemon, which then passes it on to any re-executed Exims. Exim also
3637 automatically adds the pid to debug lines when several remote deliveries are
3638 run in parallel.
3640 The &`timestamp`& selector causes the current time to be inserted at the start
3641 of all debug output lines. This can be useful when trying to track down delays
3642 in processing.
3644 If the &%debug_print%& option is set in any driver, it produces output whenever
3645 any debugging is selected, or if &%-v%& is used.
3647 .vitem &%-dd%&<&'debug&~options'&>
3648 .oindex "&%-dd%&"
3649 This option behaves exactly like &%-d%& except when used on a command that
3650 starts a daemon process. In that case, debugging is turned off for the
3651 subprocesses that the daemon creates. Thus, it is useful for monitoring the
3652 behaviour of the daemon without creating as much output as full debugging does.
3654 .vitem &%-dropcr%&
3655 .oindex "&%-dropcr%&"
3656 This is an obsolete option that is now a no-op. It used to affect the way Exim
3657 handled CR and LF characters in incoming messages. What happens now is
3658 described in section &<<SECTlineendings>>&.
3660 .vitem &%-E%&
3661 .oindex "&%-E%&"
3662 .cindex "bounce message" "generating"
3663 This option specifies that an incoming message is a locally-generated delivery
3664 failure report. It is used internally by Exim when handling delivery failures
3665 and is not intended for external use. Its only effect is to stop Exim
3666 generating certain messages to the postmaster, as otherwise message cascades
3667 could occur in some situations. As part of the same option, a message id may
3668 follow the characters &%-E%&. If it does, the log entry for the receipt of the
3669 new message contains the id, following &"R="&, as a cross-reference.
3671 .vitem &%-e%&&'x'&
3672 .oindex "&%-e%&&'x'&"
3673 There are a number of Sendmail options starting with &%-oe%& which seem to be
3674 called by various programs without the leading &%o%& in the option. For
3675 example, the &%vacation%& program uses &%-eq%&. Exim treats all options of the
3676 form &%-e%&&'x'& as synonymous with the corresponding &%-oe%&&'x'& options.
3678 .vitem &%-F%&&~<&'string'&>
3679 .oindex "&%-F%&"
3680 .cindex "sender" "name"
3681 .cindex "name" "of sender"
3682 This option sets the sender's full name for use when a locally-generated
3683 message is being accepted. In the absence of this option, the user's &'gecos'&
3684 entry from the password data is used. As users are generally permitted to alter
3685 their &'gecos'& entries, no security considerations are involved. White space
3686 between &%-F%& and the <&'string'&> is optional.
3688 .vitem &%-f%&&~<&'address'&>
3689 .oindex "&%-f%&"
3690 .cindex "sender" "address"
3691 .cindex "address" "sender"
3692 .cindex "trusted users"
3693 .cindex "envelope sender"
3694 .cindex "user" "trusted"
3695 This option sets the address of the envelope sender of a locally-generated
3696 message (also known as the return path). The option can normally be used only
3697 by a trusted user, but &%untrusted_set_sender%& can be set to allow untrusted
3698 users to use it.
3700 Processes running as root or the Exim user are always trusted. Other
3701 trusted users are defined by the &%trusted_users%& or &%trusted_groups%&
3702 options. In the absence of &%-f%&, or if the caller is not trusted, the sender
3703 of a local message is set to the caller's login name at the default qualify
3704 domain.
3706 There is one exception to the restriction on the use of &%-f%&: an empty sender
3707 can be specified by any user, trusted or not, to create a message that can
3708 never provoke a bounce. An empty sender can be specified either as an empty
3709 string, or as a pair of angle brackets with nothing between them, as in these
3710 examples of shell commands:
3711 .code
3712 exim -f '<>' user@domain
3713 exim -f "" user@domain
3714 .endd
3715 In addition, the use of &%-f%& is not restricted when testing a filter file
3716 with &%-bf%& or when testing or verifying addresses using the &%-bt%& or
3717 &%-bv%& options.
3719 Allowing untrusted users to change the sender address does not of itself make
3720 it possible to send anonymous mail. Exim still checks that the &'From:'& header
3721 refers to the local user, and if it does not, it adds a &'Sender:'& header,
3722 though this can be overridden by setting &%no_local_from_check%&.
3724 White
3725 .cindex "&""From""& line"
3726 space between &%-f%& and the <&'address'&> is optional (that is, they can be
3727 given as two arguments or one combined argument). The sender of a
3728 locally-generated message can also be set (when permitted) by an initial
3729 &"From&~"& line in the message &-- see the description of &%-bm%& above &-- but
3730 if &%-f%& is also present, it overrides &"From&~"&.
3732 .vitem &%-G%&
3733 .oindex "&%-G%&"
3734 .cindex "submission fixups, suppressing (command-line)"
3735 .new
3736 This option is equivalent to an ACL applying:
3737 .code
3738 control = suppress_local_fixups
3739 .endd
3740 for every message received. Note that Sendmail will complain about such
3741 bad formatting, where Exim silently just does not fix it up. This may change
3742 in future.
3744 As this affects audit information, the caller must be a trusted user to use
3745 this option.
3746 .wen
3748 .vitem &%-h%&&~<&'number'&>
3749 .oindex "&%-h%&"
3750 .cindex "Sendmail compatibility" "&%-h%& option ignored"
3751 This option is accepted for compatibility with Sendmail, but has no effect. (In
3752 Sendmail it overrides the &"hop count"& obtained by counting &'Received:'&
3753 headers.)
3755 .vitem &%-i%&
3756 .oindex "&%-i%&"
3757 .cindex "Solaris" "&'mail'& command"
3758 .cindex "dot" "in incoming non-SMTP message"
3759 This option, which has the same effect as &%-oi%&, specifies that a dot on a
3760 line by itself should not terminate an incoming, non-SMTP message. I can find
3761 no documentation for this option in Solaris 2.4 Sendmail, but the &'mailx'&
3762 command in Solaris 2.4 uses it. See also &%-ti%&.
3764 .new
3765 .vitem &%-L%&&~<&'tag'&>
3766 .oindex "&%-L%&"
3767 .cindex "syslog" "process name; set with flag"
3768 This option is equivalent to setting &%syslog_processname%& in the config
3769 file and setting &%log_file_path%& to &`syslog`&.
3770 Its use is restricted to administrators. The configuration file has to be
3771 read and parsed, to determine access rights, before this is set and takes
3772 effect, so early configuration file errors will not honour this flag.
3774 The tag should not be longer than 32 characters.
3775 .wen
3777 .vitem &%-M%&&~<&'message&~id'&>&~<&'message&~id'&>&~...
3778 .oindex "&%-M%&"
3779 .cindex "forcing delivery"
3780 .cindex "delivery" "forcing attempt"
3781 .cindex "frozen messages" "forcing delivery"
3782 This option requests Exim to run a delivery attempt on each message in turn. If
3783 any of the messages are frozen, they are automatically thawed before the
3784 delivery attempt. The settings of &%queue_domains%&, &%queue_smtp_domains%&,
3785 and &%hold_domains%& are ignored.
3787 Retry
3788 .cindex "hints database" "overriding retry hints"
3789 hints for any of the addresses are overridden &-- Exim tries to deliver even if
3790 the normal retry time has not yet been reached. This option requires the caller
3791 to be an admin user. However, there is an option called &%prod_requires_admin%&
3792 which can be set false to relax this restriction (and also the same requirement
3793 for the &%-q%&, &%-R%&, and &%-S%& options).
3795 The deliveries happen synchronously, that is, the original Exim process does
3796 not terminate until all the delivery attempts have finished. No output is
3797 produced unless there is a serious error. If you want to see what is happening,
3798 use the &%-v%& option as well, or inspect Exim's main log.
3800 .vitem &%-Mar%&&~<&'message&~id'&>&~<&'address'&>&~<&'address'&>&~...
3801 .oindex "&%-Mar%&"
3802 .cindex "message" "adding recipients"
3803 .cindex "recipient" "adding"
3804 This option requests Exim to add the addresses to the list of recipients of the
3805 message (&"ar"& for &"add recipients"&). The first argument must be a message
3806 id, and the remaining ones must be email addresses. However, if the message is
3807 active (in the middle of a delivery attempt), it is not altered. This option
3808 can be used only by an admin user.
3810 .vitem "&%-MC%&&~<&'transport'&>&~<&'hostname'&>&~<&'sequence&~number'&>&&&
3811 &~<&'message&~id'&>"
3812 .oindex "&%-MC%&"
3813 .cindex "SMTP" "passed connection"
3814 .cindex "SMTP" "multiple deliveries"
3815 .cindex "multiple SMTP deliveries"
3816 This option is not intended for use by external callers. It is used internally
3817 by Exim to invoke another instance of itself to deliver a waiting message using
3818 an existing SMTP connection, which is passed as the standard input. Details are
3819 given in chapter &<<CHAPSMTP>>&. This must be the final option, and the caller
3820 must be root or the Exim user in order to use it.
3822 .vitem &%-MCA%&
3823 .oindex "&%-MCA%&"
3824 This option is not intended for use by external callers. It is used internally
3825 by Exim in conjunction with the &%-MC%& option. It signifies that the
3826 connection to the remote host has been authenticated.
3828 .vitem &%-MCP%&
3829 .oindex "&%-MCP%&"
3830 This option is not intended for use by external callers. It is used internally
3831 by Exim in conjunction with the &%-MC%& option. It signifies that the server to
3832 which Exim is connected supports pipelining.
3834 .vitem &%-MCQ%&&~<&'process&~id'&>&~<&'pipe&~fd'&>
3835 .oindex "&%-MCQ%&"
3836 This option is not intended for use by external callers. It is used internally
3837 by Exim in conjunction with the &%-MC%& option when the original delivery was
3838 started by a queue runner. It passes on the process id of the queue runner,
3839 together with the file descriptor number of an open pipe. Closure of the pipe
3840 signals the final completion of the sequence of processes that are passing
3841 messages through the same SMTP connection.
3843 .vitem &%-MCS%&
3844 .oindex "&%-MCS%&"
3845 This option is not intended for use by external callers. It is used internally
3846 by Exim in conjunction with the &%-MC%& option, and passes on the fact that the
3847 SMTP SIZE option should be used on messages delivered down the existing
3848 connection.
3850 .vitem &%-MCT%&
3851 .oindex "&%-MCT%&"
3852 This option is not intended for use by external callers. It is used internally
3853 by Exim in conjunction with the &%-MC%& option, and passes on the fact that the
3854 host to which Exim is connected supports TLS encryption.
3856 .vitem &%-Mc%&&~<&'message&~id'&>&~<&'message&~id'&>&~...
3857 .oindex "&%-Mc%&"
3858 .cindex "hints database" "not overridden by &%-Mc%&"
3859 .cindex "delivery" "manually started &-- not forced"
3860 This option requests Exim to run a delivery attempt on each message in turn,
3861 but unlike the &%-M%& option, it does check for retry hints, and respects any
3862 that are found. This option is not very useful to external callers. It is
3863 provided mainly for internal use by Exim when it needs to re-invoke itself in
3864 order to regain root privilege for a delivery (see chapter &<<CHAPsecurity>>&).
3865 However, &%-Mc%& can be useful when testing, in order to run a delivery that
3866 respects retry times and other options such as &%hold_domains%& that are
3867 overridden when &%-M%& is used. Such a delivery does not count as a queue run.
3868 If you want to run a specific delivery as if in a queue run, you should use
3869 &%-q%& with a message id argument. A distinction between queue run deliveries
3870 and other deliveries is made in one or two places.
3872 .vitem &%-Mes%&&~<&'message&~id'&>&~<&'address'&>
3873 .oindex "&%-Mes%&"
3874 .cindex "message" "changing sender"
3875 .cindex "sender" "changing"
3876 This option requests Exim to change the sender address in the message to the
3877 given address, which must be a fully qualified address or &"<>"& (&"es"& for
3878 &"edit sender"&). There must be exactly two arguments. The first argument must
3879 be a message id, and the second one an email address. However, if the message
3880 is active (in the middle of a delivery attempt), its status is not altered.
3881 This option can be used only by an admin user.
3883 .vitem &%-Mf%&&~<&'message&~id'&>&~<&'message&~id'&>&~...
3884 .oindex "&%-Mf%&"
3885 .cindex "freezing messages"
3886 .cindex "message" "manually freezing"
3887 This option requests Exim to mark each listed message as &"frozen"&. This
3888 prevents any delivery attempts taking place until the message is &"thawed"&,
3889 either manually or as a result of the &%auto_thaw%& configuration option.
3890 However, if any of the messages are active (in the middle of a delivery
3891 attempt), their status is not altered. This option can be used only by an admin
3892 user.
3894 .vitem &%-Mg%&&~<&'message&~id'&>&~<&'message&~id'&>&~...
3895 .oindex "&%-Mg%&"
3896 .cindex "giving up on messages"
3897 .cindex "message" "abandoning delivery attempts"
3898 .cindex "delivery" "abandoning further attempts"
3899 This option requests Exim to give up trying to deliver the listed messages,
3900 including any that are frozen. However, if any of the messages are active,
3901 their status is not altered. For non-bounce messages, a delivery error message
3902 is sent to the sender, containing the text &"cancelled by administrator"&.
3903 Bounce messages are just discarded. This option can be used only by an admin
3904 user.
3906 .vitem &%-Mmad%&&~<&'message&~id'&>&~<&'message&~id'&>&~...
3907 .oindex "&%-Mmad%&"
3908 .cindex "delivery" "cancelling all"
3909 This option requests Exim to mark all the recipient addresses in the messages
3910 as already delivered (&"mad"& for &"mark all delivered"&). However, if any
3911 message is active (in the middle of a delivery attempt), its status is not
3912 altered. This option can be used only by an admin user.
3914 .vitem &%-Mmd%&&~<&'message&~id'&>&~<&'address'&>&~<&'address'&>&~...
3915 .oindex "&%-Mmd%&"
3916 .cindex "delivery" "cancelling by address"
3917 .cindex "recipient" "removing"
3918 .cindex "removing recipients"
3919 This option requests Exim to mark the given addresses as already delivered
3920 (&"md"& for &"mark delivered"&). The first argument must be a message id, and
3921 the remaining ones must be email addresses. These are matched to recipient
3922 addresses in the message in a case-sensitive manner. If the message is active
3923 (in the middle of a delivery attempt), its status is not altered. This option
3924 can be used only by an admin user.
3926 .vitem &%-Mrm%&&~<&'message&~id'&>&~<&'message&~id'&>&~...
3927 .oindex "&%-Mrm%&"
3928 .cindex "removing messages"
3929 .cindex "abandoning mail"
3930 .cindex "message" "manually discarding"
3931 This option requests Exim to remove the given messages from the queue. No
3932 bounce messages are sent; each message is simply forgotten. However, if any of
3933 the messages are active, their status is not altered. This option can be used
3934 only by an admin user or by the user who originally caused the message to be
3935 placed on the queue.
3937 .vitem &%-Mset%&&~<&'message&~id'&>
3938 .oindex "&%-Mset%&
3939 .cindex "testing" "string expansion"
3940 .cindex "expansion" "testing"
3941 This option is useful only in conjunction with &%-be%& (that is, when testing
3942 string expansions). Exim loads the given message from its spool before doing
3943 the test expansions, thus setting message-specific variables such as
3944 &$message_size$& and the header variables. The &$recipients$& variable is made
3945 available. This feature is provided to make it easier to test expansions that
3946 make use of these variables. However, this option can be used only by an admin
3947 user. See also &%-bem%&.
3949 .vitem &%-Mt%&&~<&'message&~id'&>&~<&'message&~id'&>&~...
3950 .oindex "&%-Mt%&"
3951 .cindex "thawing messages"
3952 .cindex "unfreezing messages"
3953 .cindex "frozen messages" "thawing"
3954 .cindex "message" "thawing frozen"
3955 This option requests Exim to &"thaw"& any of the listed messages that are
3956 &"frozen"&, so that delivery attempts can resume. However, if any of the
3957 messages are active, their status is not altered. This option can be used only
3958 by an admin user.
3960 .vitem &%-Mvb%&&~<&'message&~id'&>
3961 .oindex "&%-Mvb%&"
3962 .cindex "listing" "message body"
3963 .cindex "message" "listing body of"
3964 This option causes the contents of the message body (-D) spool file to be
3965 written to the standard output. This option can be used only by an admin user.
3967 .vitem &%-Mvc%&&~<&'message&~id'&>
3968 .oindex "&%-Mvc%&"
3969 .cindex "message" "listing in RFC 2822 format"
3970 .cindex "listing" "message in RFC 2822 format"
3971 This option causes a copy of the complete message (header lines plus body) to
3972 be written to the standard output in RFC 2822 format. This option can be used
3973 only by an admin user.
3975 .vitem &%-Mvh%&&~<&'message&~id'&>
3976 .oindex "&%-Mvh%&"
3977 .cindex "listing" "message headers"
3978 .cindex "header lines" "listing"
3979 .cindex "message" "listing header lines"
3980 This option causes the contents of the message headers (-H) spool file to be
3981 written to the standard output. This option can be used only by an admin user.
3983 .vitem &%-Mvl%&&~<&'message&~id'&>
3984 .oindex "&%-Mvl%&"
3985 .cindex "listing" "message log"
3986 .cindex "message" "listing message log"
3987 This option causes the contents of the message log spool file to be written to
3988 the standard output. This option can be used only by an admin user.
3990 .vitem &%-m%&
3991 .oindex "&%-m%&"
3992 This is apparently a synonym for &%-om%& that is accepted by Sendmail, so Exim
3993 treats it that way too.
3995 .vitem &%-N%&
3996 .oindex "&%-N%&"
3997 .cindex "debugging" "&%-N%& option"
3998 .cindex "debugging" "suppressing delivery"
3999 This is a debugging option that inhibits delivery of a message at the transport
4000 level. It implies &%-v%&. Exim goes through many of the motions of delivery &--
4001 it just doesn't actually transport the message, but instead behaves as if it
4002 had successfully done so. However, it does not make any updates to the retry
4003 database, and the log entries for deliveries are flagged with &"*>"& rather
4004 than &"=>"&.