[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(http://www.uit.co.uk/exim-book/)).
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 &%exim.org%&. These are now also hosted at the University of Cambridge. The
459 &%exim.org%& 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(http://wiki.exim.org)),
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(http://bugs.exim.org). 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 &'exim-announce@exim.org'& "Moderated, low volume announcements list"
483 .row &'exim-users@exim.org'& "General discussion list"
484 .row &'exim-dev@exim.org'& "Discussion of bugs, enhancements, etc."
485 .row &'exim-cvs@exim.org'& "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 &'pkg-exim4-users@lists.alioth.debian.org'&
493 via this web page:
494 .display
495 &url(http://lists.alioth.debian.org/mailman/listinfo/pkg-exim4-users)
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(http://www-tus.csx.cam.ac.uk/courses/exim/).
507 .section "Bug reports" "SECID5"
508 .cindex "bug reports"
509 .cindex "reporting bugs"
510 Reports of obvious bugs can be emailed to &'bugs@exim.org'& or reported
511 via the Bugzilla (&url(http://bugs.exim.org)). 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 &*ftp://ftp.csx.cam.ac.uk/pub/software/email/exim*&
523 .endd
524 This is mirrored by
525 .display
526 &*ftp://ftp.exim.org/pub/exim*&
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 &'exim.org'& 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 &'pool.sks-keyservers.net'&.
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(https://www.security.spodhuis.org/exim-trustpath).
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 A number of pieces of external code are included in the Exim distribution.
751 .ilist
752 Regular expressions are supported in the main Exim program and in the
753 Exim monitor using the freely-distributable PCRE library, copyright
754 &copy; University of Cambridge. The source to PCRE is no longer shipped with
755 Exim, so you will need to use the version of PCRE shipped with your system,
756 or obtain and install the full version of the library from
757 &url(ftp://ftp.csx.cam.ac.uk/pub/software/programming/pcre).
758 .next
759 .cindex "cdb" "acknowledgment"
760 Support for the cdb (Constant DataBase) lookup method is provided by code
761 contributed by Nigel Metheringham of (at the time he contributed it) Planet
762 Online Ltd. The implementation is completely contained within the code of Exim.
763 It does not link against an external cdb library. The code contains the
764 following statements:
766 .blockquote
767 Copyright &copy; 1998 Nigel Metheringham, Planet Online Ltd
769 This program is free software; you can redistribute it and/or modify it under
770 the terms of the GNU General Public License as published by the Free Software
771 Foundation; either version 2 of the License, or (at your option) any later
772 version.
773 This code implements Dan Bernstein's Constant DataBase (cdb) spec. Information,
774 the spec and sample code for cdb can be obtained from
775 &url(http://www.pobox.com/~djb/cdb.html). This implementation borrows
776 some code from Dan Bernstein's implementation (which has no license
777 restrictions applied to it).
778 .endblockquote
779 .next
780 .cindex "SPA authentication"
781 .cindex "Samba project"
782 .cindex "Microsoft Secure Password Authentication"
783 Client support for Microsoft's &'Secure Password Authentication'& is provided
784 by code contributed by Marc Prud'hommeaux. Server support was contributed by
785 Tom Kistner. This includes code taken from the Samba project, which is released
786 under the Gnu GPL.
787 .next
788 .cindex "Cyrus"
789 .cindex "&'pwcheck'& daemon"
790 .cindex "&'pwauthd'& daemon"
791 Support for calling the Cyrus &'pwcheck'& and &'saslauthd'& daemons is provided
792 by code taken from the Cyrus-SASL library and adapted by Alexander S.
793 Sabourenkov. The permission notice appears below, in accordance with the
794 conditions expressed therein.
796 .blockquote
797 Copyright &copy; 2001 Carnegie Mellon University. All rights reserved.
799 Redistribution and use in source and binary forms, with or without
800 modification, are permitted provided that the following conditions
801 are met:
803 .olist
804 Redistributions of source code must retain the above copyright
805 notice, this list of conditions and the following disclaimer.
806 .next
807 Redistributions in binary form must reproduce the above copyright
808 notice, this list of conditions and the following disclaimer in
809 the documentation and/or other materials provided with the
810 distribution.
811 .next
812 The name &"Carnegie Mellon University"& must not be used to
813 endorse or promote products derived from this software without
814 prior written permission. For permission or any other legal
815 details, please contact
816 .display
817 Office of Technology Transfer
818 Carnegie Mellon University
819 5000 Forbes Avenue
820 Pittsburgh, PA 15213-3890
821 (412) 268-4387, fax: (412) 268-7395
822 tech-transfer@andrew.cmu.edu
823 .endd
824 .next
825 Redistributions of any form whatsoever must retain the following
826 acknowledgment:
828 &"This product includes software developed by Computing Services
829 at Carnegie Mellon University (&url(http://www.cmu.edu/computing/)."&
838 .endlist
839 .endblockquote
841 .next
842 .cindex "Exim monitor" "acknowledgment"
843 .cindex "X-windows"
844 .cindex "Athena"
845 The Exim Monitor program, which is an X-Window application, includes
846 modified versions of the Athena StripChart and TextPop widgets.
847 This code is copyright by DEC and MIT, and their permission notice appears
848 below, in accordance with the conditions expressed therein.
850 .blockquote
851 Copyright 1987, 1988 by Digital Equipment Corporation, Maynard, Massachusetts,
852 and the Massachusetts Institute of Technology, Cambridge, Massachusetts.
854 All Rights Reserved
856 Permission to use, copy, modify, and distribute this software and its
857 documentation for any purpose and without fee is hereby granted,
858 provided that the above copyright notice appear in all copies and that
859 both that copyright notice and this permission notice appear in
860 supporting documentation, and that the names of Digital or MIT not be
861 used in advertising or publicity pertaining to distribution of the
862 software without specific, written prior permission.
871 .endblockquote
873 .next
874 Many people have contributed code fragments, some large, some small, that were
875 not covered by any specific licence requirements. It is assumed that the
876 contributors are happy to see their code incorporated into Exim under the GPL.
877 .endlist
883 . ////////////////////////////////////////////////////////////////////////////
884 . ////////////////////////////////////////////////////////////////////////////
886 .chapter "How Exim receives and delivers mail" "CHID11" &&&
887 "Receiving and delivering mail"
890 .section "Overall philosophy" "SECID10"
891 .cindex "design philosophy"
892 Exim is designed to work efficiently on systems that are permanently connected
893 to the Internet and are handling a general mix of mail. In such circumstances,
894 most messages can be delivered immediately. Consequently, Exim does not
895 maintain independent queues of messages for specific domains or hosts, though
896 it does try to send several messages in a single SMTP connection after a host
897 has been down, and it also maintains per-host retry information.
900 .section "Policy control" "SECID11"
901 .cindex "policy control" "overview"
902 Policy controls are now an important feature of MTAs that are connected to the
903 Internet. Perhaps their most important job is to stop MTAs being abused as
904 &"open relays"& by misguided individuals who send out vast amounts of
905 unsolicited junk, and want to disguise its source. Exim provides flexible
906 facilities for specifying policy controls on incoming mail:
908 .ilist
909 .cindex "&ACL;" "introduction"
910 Exim 4 (unlike previous versions of Exim) implements policy controls on
911 incoming mail by means of &'Access Control Lists'& (ACLs). Each list is a
912 series of statements that may either grant or deny access. ACLs can be used at
913 several places in the SMTP dialogue while receiving a message from a remote
914 host. However, the most common places are after each RCPT command, and at the
915 very end of the message. The sysadmin can specify conditions for accepting or
916 rejecting individual recipients or the entire message, respectively, at these
917 two points (see chapter &<<CHAPACL>>&). Denial of access results in an SMTP
918 error code.
919 .next
920 An ACL is also available for locally generated, non-SMTP messages. In this
921 case, the only available actions are to accept or deny the entire message.
922 .next
923 When Exim is compiled with the content-scanning extension, facilities are
924 provided in the ACL mechanism for passing the message to external virus and/or
925 spam scanning software. The result of such a scan is passed back to the ACL,
926 which can then use it to decide what to do with the message.
927 .next
928 When a message has been received, either from a remote host or from the local
929 host, but before the final acknowledgment has been sent, a locally supplied C
930 function called &[local_scan()]& can be run to inspect the message and decide
931 whether to accept it or not (see chapter &<<CHAPlocalscan>>&). If the message
932 is accepted, the list of recipients can be modified by the function.
933 .next
934 Using the &[local_scan()]& mechanism is another way of calling external scanner
935 software. The &%SA-Exim%& add-on package works this way. It does not require
936 Exim to be compiled with the content-scanning extension.
937 .next
938 After a message has been accepted, a further checking mechanism is available in
939 the form of the &'system filter'& (see chapter &<<CHAPsystemfilter>>&). This
940 runs at the start of every delivery process.
941 .endlist
945 .section "User filters" "SECID12"
946 .cindex "filter" "introduction"
947 .cindex "Sieve filter"
948 In a conventional Exim configuration, users are able to run private filters by
949 setting up appropriate &_.forward_& files in their home directories. See
950 chapter &<<CHAPredirect>>& (about the &(redirect)& router) for the
951 configuration needed to support this, and the separate document entitled
952 &'Exim's interfaces to mail filtering'& for user details. Two different kinds
953 of filtering are available:
955 .ilist
956 Sieve filters are written in the standard filtering language that is defined
957 by RFC 3028.
958 .next
959 Exim filters are written in a syntax that is unique to Exim, but which is more
960 powerful than Sieve, which it pre-dates.
961 .endlist
963 User filters are run as part of the routing process, described below.
967 .section "Message identification" "SECTmessiden"
968 .cindex "message ids" "details of format"
969 .cindex "format" "of message id"
970 .cindex "id of message"
971 .cindex "base62"
972 .cindex "base36"
973 .cindex "Darwin"
974 .cindex "Cygwin"
975 Every message handled by Exim is given a &'message id'& which is sixteen
976 characters long. It is divided into three parts, separated by hyphens, for
977 example &`16VDhn-0001bo-D3`&. Each part is a sequence of letters and digits,
978 normally encoding numbers in base 62. However, in the Darwin operating
979 system (Mac OS X) and when Exim is compiled to run under Cygwin, base 36
980 (avoiding the use of lower case letters) is used instead, because the message
981 id is used to construct file names, and the names of files in those systems are
982 not always case-sensitive.
984 .cindex "pid (process id)" "re-use of"
985 The detail of the contents of the message id have changed as Exim has evolved.
986 Earlier versions relied on the operating system not re-using a process id (pid)
987 within one second. On modern operating systems, this assumption can no longer
988 be made, so the algorithm had to be changed. To retain backward compatibility,
989 the format of the message id was retained, which is why the following rules are
990 somewhat eccentric:
992 .ilist
993 The first six characters of the message id are the time at which the message
994 started to be received, to a granularity of one second. That is, this field
995 contains the number of seconds since the start of the epoch (the normal Unix
996 way of representing the date and time of day).
997 .next
998 After the first hyphen, the next six characters are the id of the process that
999 received the message.
1000 .next
1001 There are two different possibilities for the final two characters:
1002 .olist
1003 .oindex "&%localhost_number%&"
1004 If &%localhost_number%& is not set, this value is the fractional part of the
1005 time of reception, normally in units of 1/2000 of a second, but for systems
1006 that must use base 36 instead of base 62 (because of case-insensitive file
1007 systems), the units are 1/1000 of a second.
1008 .next
1009 If &%localhost_number%& is set, it is multiplied by 200 (100) and added to
1010 the fractional part of the time, which in this case is in units of 1/200
1011 (1/100) of a second.
1012 .endlist
1013 .endlist
1015 After a message has been received, Exim waits for the clock to tick at the
1016 appropriate resolution before proceeding, so that if another message is
1017 received by the same process, or by another process with the same (re-used)
1018 pid, it is guaranteed that the time will be different. In most cases, the clock
1019 will already have ticked while the message was being received.
1022 .section "Receiving mail" "SECID13"
1023 .cindex "receiving mail"
1024 .cindex "message" "reception"
1025 The only way Exim can receive mail from another host is using SMTP over
1026 TCP/IP, in which case the sender and recipient addresses are transferred using
1027 SMTP commands. However, from a locally running process (such as a user's MUA),
1028 there are several possibilities:
1030 .ilist
1031 If the process runs Exim with the &%-bm%& option, the message is read
1032 non-interactively (usually via a pipe), with the recipients taken from the
1033 command line, or from the body of the message if &%-t%& is also used.
1034 .next
1035 If the process runs Exim with the &%-bS%& option, the message is also read
1036 non-interactively, but in this case the recipients are listed at the start of
1037 the message in a series of SMTP RCPT commands, terminated by a DATA
1038 command. This is so-called &"batch SMTP"& format,
1039 but it isn't really SMTP. The SMTP commands are just another way of passing
1040 envelope addresses in a non-interactive submission.
1041 .next
1042 If the process runs Exim with the &%-bs%& option, the message is read
1043 interactively, using the SMTP protocol. A two-way pipe is normally used for
1044 passing data between the local process and the Exim process.
1045 This is &"real"& SMTP and is handled in the same way as SMTP over TCP/IP. For
1046 example, the ACLs for SMTP commands are used for this form of submission.
1047 .next
1048 A local process may also make a TCP/IP call to the host's loopback address
1049 ( or any other of its IP addresses. When receiving messages, Exim
1050 does not treat the loopback address specially. It treats all such connections
1051 in the same way as connections from other hosts.
1052 .endlist
1055 .cindex "message sender, constructed by Exim"
1056 .cindex "sender" "constructed by Exim"
1057 In the three cases that do not involve TCP/IP, the sender address is
1058 constructed from the login name of the user that called Exim and a default
1059 qualification domain (which can be set by the &%qualify_domain%& configuration
1060 option). For local or batch SMTP, a sender address that is passed using the
1061 SMTP MAIL command is ignored. However, the system administrator may allow
1062 certain users (&"trusted users"&) to specify a different sender address
1063 unconditionally, or all users to specify certain forms of different sender
1064 address. The &%-f%& option or the SMTP MAIL command is used to specify these
1065 different addresses. See section &<<SECTtrustedadmin>>& for details of trusted
1066 users, and the &%untrusted_set_sender%& option for a way of allowing untrusted
1067 users to change sender addresses.
1069 Messages received by either of the non-interactive mechanisms are subject to
1070 checking by the non-SMTP ACL, if one is defined. Messages received using SMTP
1071 (either over TCP/IP, or interacting with a local process) can be checked by a
1072 number of ACLs that operate at different times during the SMTP session. Either
1073 individual recipients, or the entire message, can be rejected if local policy
1074 requirements are not met. The &[local_scan()]& function (see chapter
1075 &<<CHAPlocalscan>>&) is run for all incoming messages.
1077 Exim can be configured not to start a delivery process when a message is
1078 received; this can be unconditional, or depend on the number of incoming SMTP
1079 connections or the system load. In these situations, new messages wait on the
1080 queue until a queue runner process picks them up. However, in standard
1081 configurations under normal conditions, delivery is started as soon as a
1082 message is received.
1088 .section "Handling an incoming message" "SECID14"
1089 .cindex "spool directory" "files that hold a message"
1090 .cindex "file" "how a message is held"
1091 When Exim accepts a message, it writes two files in its spool directory. The
1092 first contains the envelope information, the current status of the message, and
1093 the header lines, and the second contains the body of the message. The names of
1094 the two spool files consist of the message id, followed by &`-H`& for the
1095 file containing the envelope and header, and &`-D`& for the data file.
1097 .cindex "spool directory" "&_input_& sub-directory"
1098 By default all these message files are held in a single directory called
1099 &_input_& inside the general Exim spool directory. Some operating systems do
1100 not perform very well if the number of files in a directory gets large; to
1101 improve performance in such cases, the &%split_spool_directory%& option can be
1102 used. This causes Exim to split up the input files into 62 sub-directories
1103 whose names are single letters or digits. When this is done, the queue is
1104 processed one sub-directory at a time instead of all at once, which can improve
1105 overall performance even when there are not enough files in each directory to
1106 affect file system performance.
1108 The envelope information consists of the address of the message's sender and
1109 the addresses of the recipients. This information is entirely separate from
1110 any addresses contained in the header lines. The status of the message includes
1111 a list of recipients who have already received the message. The format of the
1112 first spool file is described in chapter &<<CHAPspool>>&.
1114 .cindex "rewriting" "addresses"
1115 Address rewriting that is specified in the rewrite section of the configuration
1116 (see chapter &<<CHAPrewrite>>&) is done once and for all on incoming addresses,
1117 both in the header lines and the envelope, at the time the message is accepted.
1118 If during the course of delivery additional addresses are generated (for
1119 example, via aliasing), these new addresses are rewritten as soon as they are
1120 generated. At the time a message is actually delivered (transported) further
1121 rewriting can take place; because this is a transport option, it can be
1122 different for different forms of delivery. It is also possible to specify the
1123 addition or removal of certain header lines at the time the message is
1124 delivered (see chapters &<<CHAProutergeneric>>& and
1125 &<<CHAPtransportgeneric>>&).
1129 .section "Life of a message" "SECID15"
1130 .cindex "message" "life of"
1131 .cindex "message" "frozen"
1132 A message remains in the spool directory until it is completely delivered to
1133 its recipients or to an error address, or until it is deleted by an
1134 administrator or by the user who originally created it. In cases when delivery
1135 cannot proceed &-- for example, when a message can neither be delivered to its
1136 recipients nor returned to its sender, the message is marked &"frozen"& on the
1137 spool, and no more deliveries are attempted.
1139 .cindex "frozen messages" "thawing"
1140 .cindex "message" "thawing frozen"
1141 An administrator can &"thaw"& such messages when the problem has been
1142 corrected, and can also freeze individual messages by hand if necessary. In
1143 addition, an administrator can force a delivery error, causing a bounce message
1144 to be sent.
1146 .oindex "&%timeout_frozen_after%&"
1147 .oindex "&%ignore_bounce_errors_after%&"
1148 There are options called &%ignore_bounce_errors_after%& and
1149 &%timeout_frozen_after%&, which discard frozen messages after a certain time.
1150 The first applies only to frozen bounces, the second to any frozen messages.
1152 .cindex "message" "log file for"
1153 .cindex "log" "file for each message"
1154 While Exim is working on a message, it writes information about each delivery
1155 attempt to its main log file. This includes successful, unsuccessful, and
1156 delayed deliveries for each recipient (see chapter &<<CHAPlog>>&). The log
1157 lines are also written to a separate &'message log'& file for each message.
1158 These logs are solely for the benefit of the administrator, and are normally
1159 deleted along with the spool files when processing of a message is complete.
1160 The use of individual message logs can be disabled by setting
1161 &%no_message_logs%&; this might give an improvement in performance on very busy
1162 systems.
1164 .cindex "journal file"
1165 .cindex "file" "journal"
1166 All the information Exim itself needs to set up a delivery is kept in the first
1167 spool file, along with the header lines. When a successful delivery occurs, the
1168 address is immediately written at the end of a journal file, whose name is the
1169 message id followed by &`-J`&. At the end of a delivery run, if there are some
1170 addresses left to be tried again later, the first spool file (the &`-H`& file)
1171 is updated to indicate which these are, and the journal file is then deleted.
1172 Updating the spool file is done by writing a new file and renaming it, to
1173 minimize the possibility of data loss.
1175 Should the system or the program crash after a successful delivery but before
1176 the spool file has been updated, the journal is left lying around. The next
1177 time Exim attempts to deliver the message, it reads the journal file and
1178 updates the spool file before proceeding. This minimizes the chances of double
1179 deliveries caused by crashes.
1183 .section "Processing an address for delivery" "SECTprocaddress"
1184 .cindex "drivers" "definition of"
1185 .cindex "router" "definition of"
1186 .cindex "transport" "definition of"
1187 The main delivery processing elements of Exim are called &'routers'& and
1188 &'transports'&, and collectively these are known as &'drivers'&. Code for a
1189 number of them is provided in the source distribution, and compile-time options
1190 specify which ones are included in the binary. Run time options specify which
1191 ones are actually used for delivering messages.
1193 .cindex "drivers" "instance definition"
1194 Each driver that is specified in the run time configuration is an &'instance'&
1195 of that particular driver type. Multiple instances are allowed; for example,
1196 you can set up several different &(smtp)& transports, each with different
1197 option values that might specify different ports or different timeouts. Each
1198 instance has its own identifying name. In what follows we will normally use the
1199 instance name when discussing one particular instance (that is, one specific
1200 configuration of the driver), and the generic driver name when discussing
1201 the driver's features in general.
1203 A &'router'& is a driver that operates on an address, either determining how
1204 its delivery should happen, by assigning it to a specific transport, or
1205 converting the address into one or more new addresses (for example, via an
1206 alias file). A router may also explicitly choose to fail an address, causing it
1207 to be bounced.
1209 A &'transport'& is a driver that transmits a copy of the message from Exim's
1210 spool to some destination. There are two kinds of transport: for a &'local'&
1211 transport, the destination is a file or a pipe on the local host, whereas for a
1212 &'remote'& transport the destination is some other host. A message is passed
1213 to a specific transport as a result of successful routing. If a message has
1214 several recipients, it may be passed to a number of different transports.
1216 .cindex "preconditions" "definition of"
1217 An address is processed by passing it to each configured router instance in
1218 turn, subject to certain preconditions, until a router accepts the address or
1219 specifies that it should be bounced. We will describe this process in more
1220 detail shortly. First, as a simple example, we consider how each recipient
1221 address in a message is processed in a small configuration of three routers.
1223 To make this a more concrete example, it is described in terms of some actual
1224 routers, but remember, this is only an example. You can configure Exim's
1225 routers in many different ways, and there may be any number of routers in a
1226 configuration.
1228 The first router that is specified in a configuration is often one that handles
1229 addresses in domains that are not recognized specially by the local host. These
1230 are typically addresses for arbitrary domains on the Internet. A precondition
1231 is set up which looks for the special domains known to the host (for example,
1232 its own domain name), and the router is run for addresses that do &'not'&
1233 match. Typically, this is a router that looks up domains in the DNS in order to
1234 find the hosts to which this address routes. If it succeeds, the address is
1235 assigned to a suitable SMTP transport; if it does not succeed, the router is
1236 configured to fail the address.
1238 The second router is reached only when the domain is recognized as one that
1239 &"belongs"& to the local host. This router does redirection &-- also known as
1240 aliasing and forwarding. When it generates one or more new addresses from the
1241 original, each of them is routed independently from the start. Otherwise, the
1242 router may cause an address to fail, or it may simply decline to handle the
1243 address, in which case the address is passed to the next router.
1245 The final router in many configurations is one that checks to see if the
1246 address belongs to a local mailbox. The precondition may involve a check to
1247 see if the local part is the name of a login account, or it may look up the
1248 local part in a file or a database. If its preconditions are not met, or if
1249 the router declines, we have reached the end of the routers. When this happens,
1250 the address is bounced.
1254 .section "Processing an address for verification" "SECID16"
1255 .cindex "router" "for verification"
1256 .cindex "verifying address" "overview"
1257 As well as being used to decide how to deliver to an address, Exim's routers
1258 are also used for &'address verification'&. Verification can be requested as
1259 one of the checks to be performed in an ACL for incoming messages, on both
1260 sender and recipient addresses, and it can be tested using the &%-bv%& and
1261 &%-bvs%& command line options.
1263 When an address is being verified, the routers are run in &"verify mode"&. This
1264 does not affect the way the routers work, but it is a state that can be
1265 detected. By this means, a router can be skipped or made to behave differently
1266 when verifying. A common example is a configuration in which the first router
1267 sends all messages to a message-scanning program, unless they have been
1268 previously scanned. Thus, the first router accepts all addresses without any
1269 checking, making it useless for verifying. Normally, the &%no_verify%& option
1270 would be set for such a router, causing it to be skipped in verify mode.
1275 .section "Running an individual router" "SECTrunindrou"
1276 .cindex "router" "running details"
1277 .cindex "preconditions" "checking"
1278 .cindex "router" "result of running"
1279 As explained in the example above, a number of preconditions are checked before
1280 running a router. If any are not met, the router is skipped, and the address is
1281 passed to the next router. When all the preconditions on a router &'are'& met,
1282 the router is run. What happens next depends on the outcome, which is one of
1283 the following:
1285 .ilist
1286 &'accept'&: The router accepts the address, and either assigns it to a
1287 transport, or generates one or more &"child"& addresses. Processing the
1288 original address ceases,
1289 .oindex "&%unseen%&"
1290 unless the &%unseen%& option is set on the router. This option
1291 can be used to set up multiple deliveries with different routing (for example,
1292 for keeping archive copies of messages). When &%unseen%& is set, the address is
1293 passed to the next router. Normally, however, an &'accept'& return marks the
1294 end of routing.
1296 Any child addresses generated by the router are processed independently,
1297 starting with the first router by default. It is possible to change this by
1298 setting the &%redirect_router%& option to specify which router to start at for
1299 child addresses. Unlike &%pass_router%& (see below) the router specified by
1300 &%redirect_router%& may be anywhere in the router configuration.
1301 .next
1302 &'pass'&: The router recognizes the address, but cannot handle it itself. It
1303 requests that the address be passed to another router. By default the address
1304 is passed to the next router, but this can be changed by setting the
1305 &%pass_router%& option. However, (unlike &%redirect_router%&) the named router
1306 must be below the current router (to avoid loops).
1307 .next
1308 &'decline'&: The router declines to accept the address because it does not
1309 recognize it at all. By default, the address is passed to the next router, but
1310 this can be prevented by setting the &%no_more%& option. When &%no_more%& is
1311 set, all the remaining routers are skipped. In effect, &%no_more%& converts
1312 &'decline'& into &'fail'&.
1313 .next
1314 &'fail'&: The router determines that the address should fail, and queues it for
1315 the generation of a bounce message. There is no further processing of the
1316 original address unless &%unseen%& is set on the router.
1317 .next
1318 &'defer'&: The router cannot handle the address at the present time. (A
1319 database may be offline, or a DNS lookup may have timed out.) No further
1320 processing of the address happens in this delivery attempt. It is tried again
1321 next time the message is considered for delivery.
1322 .next
1323 &'error'&: There is some error in the router (for example, a syntax error in
1324 its configuration). The action is as for defer.
1325 .endlist
1327 If an address reaches the end of the routers without having been accepted by
1328 any of them, it is bounced as unrouteable. The default error message in this
1329 situation is &"unrouteable address"&, but you can set your own message by
1330 making use of the &%cannot_route_message%& option. This can be set for any
1331 router; the value from the last router that &"saw"& the address is used.
1333 Sometimes while routing you want to fail a delivery when some conditions are
1334 met but others are not, instead of passing the address on for further routing.
1335 You can do this by having a second router that explicitly fails the delivery
1336 when the relevant conditions are met. The &(redirect)& router has a &"fail"&
1337 facility for this purpose.
1340 .section "Duplicate addresses" "SECID17"
1341 .cindex "case of local parts"
1342 .cindex "address duplicate, discarding"
1343 .cindex "duplicate addresses"
1344 Once routing is complete, Exim scans the addresses that are assigned to local
1345 and remote transports, and discards any duplicates that it finds. During this
1346 check, local parts are treated as case-sensitive. This happens only when
1347 actually delivering a message; when testing routers with &%-bt%&, all the
1348 routed addresses are shown.
1352 .section "Router preconditions" "SECTrouprecon"
1353 .cindex "router" "preconditions, order of processing"
1354 .cindex "preconditions" "order of processing"
1355 The preconditions that are tested for each router are listed below, in the
1356 order in which they are tested. The individual configuration options are
1357 described in more detail in chapter &<<CHAProutergeneric>>&.
1359 .ilist
1360 The &%local_part_prefix%& and &%local_part_suffix%& options can specify that
1361 the local parts handled by the router may or must have certain prefixes and/or
1362 suffixes. If a mandatory affix (prefix or suffix) is not present, the router is
1363 skipped. These conditions are tested first. When an affix is present, it is
1364 removed from the local part before further processing, including the evaluation
1365 of any other conditions.
1366 .next
1367 Routers can be designated for use only when not verifying an address, that is,
1368 only when routing it for delivery (or testing its delivery routing). If the
1369 &%verify%& option is set false, the router is skipped when Exim is verifying an
1370 address.
1371 Setting the &%verify%& option actually sets two options, &%verify_sender%& and
1372 &%verify_recipient%&, which independently control the use of the router for
1373 sender and recipient verification. You can set these options directly if
1374 you want a router to be used for only one type of verification.
1375 Note that cutthrough delivery is classed as a recipient verification
1376 for this purpose.
1377 .next
1378 If the &%address_test%& option is set false, the router is skipped when Exim is
1379 run with the &%-bt%& option to test an address routing. This can be helpful
1380 when the first router sends all new messages to a scanner of some sort; it
1381 makes it possible to use &%-bt%& to test subsequent delivery routing without
1382 having to simulate the effect of the scanner.
1383 .next
1384 Routers can be designated for use only when verifying an address, as
1385 opposed to routing it for delivery. The &%verify_only%& option controls this.
1386 Again, cutthrough delibery counts as a verification.
1387 .next
1388 Individual routers can be explicitly skipped when running the routers to
1389 check an address given in the SMTP EXPN command (see the &%expn%& option).
1390 .next
1391 If the &%domains%& option is set, the domain of the address must be in the set
1392 of domains that it defines.
1393 .next
1394 .vindex "&$local_part_prefix$&"
1395 .vindex "&$local_part$&"
1396 .vindex "&$local_part_suffix$&"
1397 If the &%local_parts%& option is set, the local part of the address must be in
1398 the set of local parts that it defines. If &%local_part_prefix%& or
1399 &%local_part_suffix%& is in use, the prefix or suffix is removed from the local
1400 part before this check. If you want to do precondition tests on local parts
1401 that include affixes, you can do so by using a &%condition%& option (see below)
1402 that uses the variables &$local_part$&, &$local_part_prefix$&, and
1403 &$local_part_suffix$& as necessary.
1404 .next
1405 .vindex "&$local_user_uid$&"
1406 .vindex "&$local_user_gid$&"
1407 .vindex "&$home$&"
1408 If the &%check_local_user%& option is set, the local part must be the name of
1409 an account on the local host. If this check succeeds, the uid and gid of the
1410 local user are placed in &$local_user_uid$& and &$local_user_gid$& and the
1411 user's home directory is placed in &$home$&; these values can be used in the
1412 remaining preconditions.
1413 .next
1414 If the &%router_home_directory%& option is set, it is expanded at this point,
1415 because it overrides the value of &$home$&. If this expansion were left till
1416 later, the value of &$home$& as set by &%check_local_user%& would be used in
1417 subsequent tests. Having two different values of &$home$& in the same router
1418 could lead to confusion.
1419 .next
1420 If the &%senders%& option is set, the envelope sender address must be in the
1421 set of addresses that it defines.
1422 .next
1423 If the &%require_files%& option is set, the existence or non-existence of
1424 specified files is tested.
1425 .next
1426 .cindex "customizing" "precondition"
1427 If the &%condition%& option is set, it is evaluated and tested. This option
1428 uses an expanded string to allow you to set up your own custom preconditions.
1429 Expanded strings are described in chapter &<<CHAPexpand>>&.
1430 .endlist
1433 Note that &%require_files%& comes near the end of the list, so you cannot use
1434 it to check for the existence of a file in which to lookup up a domain, local
1435 part, or sender. However, as these options are all expanded, you can use the
1436 &%exists%& expansion condition to make such tests within each condition. The
1437 &%require_files%& option is intended for checking files that the router may be
1438 going to use internally, or which are needed by a specific transport (for
1439 example, &_.procmailrc_&).
1443 .section "Delivery in detail" "SECID18"
1444 .cindex "delivery" "in detail"
1445 When a message is to be delivered, the sequence of events is as follows:
1447 .ilist
1448 If a system-wide filter file is specified, the message is passed to it. The
1449 filter may add recipients to the message, replace the recipients, discard the
1450 message, cause a new message to be generated, or cause the message delivery to
1451 fail. The format of the system filter file is the same as for Exim user filter
1452 files, described in the separate document entitled &'Exim's interfaces to mail
1453 filtering'&.
1454 .cindex "Sieve filter" "not available for system filter"
1455 (&*Note*&: Sieve cannot be used for system filter files.)
1457 Some additional features are available in system filters &-- see chapter
1458 &<<CHAPsystemfilter>>& for details. Note that a message is passed to the system
1459 filter only once per delivery attempt, however many recipients it has. However,
1460 if there are several delivery attempts because one or more addresses could not
1461 be immediately delivered, the system filter is run each time. The filter
1462 condition &%first_delivery%& can be used to detect the first run of the system
1463 filter.
1464 .next
1465 Each recipient address is offered to each configured router in turn, subject to
1466 its preconditions, until one is able to handle it. If no router can handle the
1467 address, that is, if they all decline, the address is failed. Because routers
1468 can be targeted at particular domains, several locally handled domains can be
1469 processed entirely independently of each other.
1470 .next
1471 .cindex "routing" "loops in"
1472 .cindex "loop" "while routing"
1473 A router that accepts an address may assign it to a local or a remote
1474 transport. However, the transport is not run at this time. Instead, the address
1475 is placed on a list for the particular transport, which will be run later.
1476 Alternatively, the router may generate one or more new addresses (typically
1477 from alias, forward, or filter files). New addresses are fed back into this
1478 process from the top, but in order to avoid loops, a router ignores any address
1479 which has an identically-named ancestor that was processed by itself.
1480 .next
1481 When all the routing has been done, addresses that have been successfully
1482 handled are passed to their assigned transports. When local transports are
1483 doing real local deliveries, they handle only one address at a time, but if a
1484 local transport is being used as a pseudo-remote transport (for example, to
1485 collect batched SMTP messages for transmission by some other means) multiple
1486 addresses can be handled. Remote transports can always handle more than one
1487 address at a time, but can be configured not to do so, or to restrict multiple
1488 addresses to the same domain.
1489 .next
1490 Each local delivery to a file or a pipe runs in a separate process under a
1491 non-privileged uid, and these deliveries are run one at a time. Remote
1492 deliveries also run in separate processes, normally under a uid that is private
1493 to Exim (&"the Exim user"&), but in this case, several remote deliveries can be
1494 run in parallel. The maximum number of simultaneous remote deliveries for any
1495 one message is set by the &%remote_max_parallel%& option.
1496 The order in which deliveries are done is not defined, except that all local
1497 deliveries happen before any remote deliveries.
1498 .next
1499 .cindex "queue runner"
1500 When it encounters a local delivery during a queue run, Exim checks its retry
1501 database to see if there has been a previous temporary delivery failure for the
1502 address before running the local transport. If there was a previous failure,
1503 Exim does not attempt a new delivery until the retry time for the address is
1504 reached. However, this happens only for delivery attempts that are part of a
1505 queue run. Local deliveries are always attempted when delivery immediately
1506 follows message reception, even if retry times are set for them. This makes for
1507 better behaviour if one particular message is causing problems (for example,
1508 causing quota overflow, or provoking an error in a filter file).
1509 .next
1510 .cindex "delivery" "retry in remote transports"
1511 Remote transports do their own retry handling, since an address may be
1512 deliverable to one of a number of hosts, each of which may have a different
1513 retry time. If there have been previous temporary failures and no host has
1514 reached its retry time, no delivery is attempted, whether in a queue run or
1515 not. See chapter &<<CHAPretry>>& for details of retry strategies.
1516 .next
1517 If there were any permanent errors, a bounce message is returned to an
1518 appropriate address (the sender in the common case), with details of the error
1519 for each failing address. Exim can be configured to send copies of bounce
1520 messages to other addresses.
1521 .next
1522 .cindex "delivery" "deferral"
1523 If one or more addresses suffered a temporary failure, the message is left on
1524 the queue, to be tried again later. Delivery of these addresses is said to be
1525 &'deferred'&.
1526 .next
1527 When all the recipient addresses have either been delivered or bounced,
1528 handling of the message is complete. The spool files and message log are
1529 deleted, though the message log can optionally be preserved if required.
1530 .endlist
1535 .section "Retry mechanism" "SECID19"
1536 .cindex "delivery" "retry mechanism"
1537 .cindex "retry" "description of mechanism"
1538 .cindex "queue runner"
1539 Exim's mechanism for retrying messages that fail to get delivered at the first
1540 attempt is the queue runner process. You must either run an Exim daemon that
1541 uses the &%-q%& option with a time interval to start queue runners at regular
1542 intervals, or use some other means (such as &'cron'&) to start them. If you do
1543 not arrange for queue runners to be run, messages that fail temporarily at the
1544 first attempt will remain on your queue for ever. A queue runner process works
1545 its way through the queue, one message at a time, trying each delivery that has
1546 passed its retry time.
1547 You can run several queue runners at once.
1549 Exim uses a set of configured rules to determine when next to retry the failing
1550 address (see chapter &<<CHAPretry>>&). These rules also specify when Exim
1551 should give up trying to deliver to the address, at which point it generates a
1552 bounce message. If no retry rules are set for a particular host, address, and
1553 error combination, no retries are attempted, and temporary errors are treated
1554 as permanent.
1558 .section "Temporary delivery failure" "SECID20"
1559 .cindex "delivery" "temporary failure"
1560 There are many reasons why a message may not be immediately deliverable to a
1561 particular address. Failure to connect to a remote machine (because it, or the
1562 connection to it, is down) is one of the most common. Temporary failures may be
1563 detected during routing as well as during the transport stage of delivery.
1564 Local deliveries may be delayed if NFS files are unavailable, or if a mailbox
1565 is on a file system where the user is over quota. Exim can be configured to
1566 impose its own quotas on local mailboxes; where system quotas are set they will
1567 also apply.
1569 If a host is unreachable for a period of time, a number of messages may be
1570 waiting for it by the time it recovers, and sending them in a single SMTP
1571 connection is clearly beneficial. Whenever a delivery to a remote host is
1572 deferred,
1573 .cindex "hints database"
1574 Exim makes a note in its hints database, and whenever a successful
1575 SMTP delivery has happened, it looks to see if any other messages are waiting
1576 for the same host. If any are found, they are sent over the same SMTP
1577 connection, subject to a configuration limit as to the maximum number in any
1578 one connection.
1582 .section "Permanent delivery failure" "SECID21"
1583 .cindex "delivery" "permanent failure"
1584 .cindex "bounce message" "when generated"
1585 When a message cannot be delivered to some or all of its intended recipients, a
1586 bounce message is generated. Temporary delivery failures turn into permanent
1587 errors when their timeout expires. All the addresses that fail in a given
1588 delivery attempt are listed in a single message. If the original message has
1589 many recipients, it is possible for some addresses to fail in one delivery
1590 attempt and others to fail subsequently, giving rise to more than one bounce
1591 message. The wording of bounce messages can be customized by the administrator.
1592 See chapter &<<CHAPemsgcust>>& for details.
1594 .cindex "&'X-Failed-Recipients:'& header line"
1595 Bounce messages contain an &'X-Failed-Recipients:'& header line that lists the
1596 failed addresses, for the benefit of programs that try to analyse such messages
1597 automatically.
1599 .cindex "bounce message" "recipient of"
1600 A bounce message is normally sent to the sender of the original message, as
1601 obtained from the message's envelope. For incoming SMTP messages, this is the
1602 address given in the MAIL command. However, when an address is expanded via a
1603 forward or alias file, an alternative address can be specified for delivery
1604 failures of the generated addresses. For a mailing list expansion (see section
1605 &<<SECTmailinglists>>&) it is common to direct bounce messages to the manager
1606 of the list.
1610 .section "Failures to deliver bounce messages" "SECID22"
1611 .cindex "bounce message" "failure to deliver"
1612 If a bounce message (either locally generated or received from a remote host)
1613 itself suffers a permanent delivery failure, the message is left on the queue,
1614 but it is frozen, awaiting the attention of an administrator. There are options
1615 that can be used to make Exim discard such failed messages, or to keep them
1616 for only a short time (see &%timeout_frozen_after%& and
1617 &%ignore_bounce_errors_after%&).
1623 . ////////////////////////////////////////////////////////////////////////////
1624 . ////////////////////////////////////////////////////////////////////////////
1626 .chapter "Building and installing Exim" "CHID3"
1627 .scindex IIDbuex "building Exim"
1629 .section "Unpacking" "SECID23"
1630 Exim is distributed as a gzipped or bzipped tar file which, when unpacked,
1631 creates a directory with the name of the current release (for example,
1632 &_exim-&version()_&) into which the following files are placed:
1634 .table2 140pt
1635 .irow &_ACKNOWLEDGMENTS_& "contains some acknowledgments"
1636 .irow &_CHANGES_& "contains a reference to where changes are &&&
1637 documented"
1638 .irow &_LICENCE_& "the GNU General Public Licence"
1639 .irow &_Makefile_& "top-level make file"
1640 .irow &_NOTICE_& "conditions for the use of Exim"
1641 .irow &_README_& "list of files, directories and simple build &&&
1642 instructions"
1643 .endtable
1645 Other files whose names begin with &_README_& may also be present. The
1646 following subdirectories are created:
1648 .table2 140pt
1649 .irow &_Local_& "an empty directory for local configuration files"
1650 .irow &_OS_& "OS-specific files"
1651 .irow &_doc_& "documentation files"
1652 .irow &_exim_monitor_& "source files for the Exim monitor"
1653 .irow &_scripts_& "scripts used in the build process"
1654 .irow &_src_& "remaining source files"
1655 .irow &_util_& "independent utilities"
1656 .endtable
1658 The main utility programs are contained in the &_src_& directory, and are built
1659 with the Exim binary. The &_util_& directory contains a few optional scripts
1660 that may be useful to some sites.
1663 .section "Multiple machine architectures and operating systems" "SECID24"
1664 .cindex "building Exim" "multiple OS/architectures"
1665 The building process for Exim is arranged to make it easy to build binaries for
1666 a number of different architectures and operating systems from the same set of
1667 source files. Compilation does not take place in the &_src_& directory.
1668 Instead, a &'build directory'& is created for each architecture and operating
1669 system.
1670 .cindex "symbolic link" "to build directory"
1671 Symbolic links to the sources are installed in this directory, which is where
1672 the actual building takes place. In most cases, Exim can discover the machine
1673 architecture and operating system for itself, but the defaults can be
1674 overridden if necessary.
1677 .section "PCRE library" "SECTpcre"
1678 .cindex "PCRE library"
1679 Exim no longer has an embedded PCRE library as the vast majority of
1680 modern systems include PCRE as a system library, although you may need
1681 to install the PCRE or PCRE development package for your operating
1682 system. If your system has a normal PCRE installation the Exim build
1683 process will need no further configuration. If the library or the
1684 headers are in an unusual location you will need to either set the PCRE_LIBS
1685 and INCLUDE directives appropriately,
1686 or set PCRE_CONFIG=yes to use the installed &(pcre-config)& command.
1687 If your operating system has no
1688 PCRE support then you will need to obtain and build the current PCRE
1689 from &url(ftp://ftp.csx.cam.ac.uk/pub/software/programming/pcre/).
1690 More information on PCRE is available at &url(http://www.pcre.org/).
1692 .section "DBM libraries" "SECTdb"
1693 .cindex "DBM libraries" "discussion of"
1694 .cindex "hints database" "DBM files used for"
1695 Even if you do not use any DBM files in your configuration, Exim still needs a
1696 DBM library in order to operate, because it uses indexed files for its hints
1697 databases. Unfortunately, there are a number of DBM libraries in existence, and
1698 different operating systems often have different ones installed.
1700 .cindex "Solaris" "DBM library for"
1701 .cindex "IRIX, DBM library for"
1702 .cindex "BSD, DBM library for"
1703 .cindex "Linux, DBM library for"
1704 If you are using Solaris, IRIX, one of the modern BSD systems, or a modern
1705 Linux distribution, the DBM configuration should happen automatically, and you
1706 may be able to ignore this section. Otherwise, you may have to learn more than
1707 you would like about DBM libraries from what follows.
1709 .cindex "&'ndbm'& DBM library"
1710 Licensed versions of Unix normally contain a library of DBM functions operating
1711 via the &'ndbm'& interface, and this is what Exim expects by default. Free
1712 versions of Unix seem to vary in what they contain as standard. In particular,
1713 some early versions of Linux have no default DBM library, and different
1714 distributors have chosen to bundle different libraries with their packaged
1715 versions. However, the more recent releases seem to have standardized on the
1716 Berkeley DB library.
1718 Different DBM libraries have different conventions for naming the files they
1719 use. When a program opens a file called &_dbmfile_&, there are several
1720 possibilities:
1722 .olist
1723 A traditional &'ndbm'& implementation, such as that supplied as part of
1724 Solaris, operates on two files called &_dbmfile.dir_& and &_dbmfile.pag_&.
1725 .next
1726 .cindex "&'gdbm'& DBM library"
1727 The GNU library, &'gdbm'&, operates on a single file. If used via its &'ndbm'&
1728 compatibility interface it makes two different hard links to it with names
1729 &_dbmfile.dir_& and &_dbmfile.pag_&, but if used via its native interface, the
1730 file name is used unmodified.
1731 .next
1732 .cindex "Berkeley DB library"
1733 The Berkeley DB package, if called via its &'ndbm'& compatibility interface,
1734 operates on a single file called &_dbmfile.db_&, but otherwise looks to the
1735 programmer exactly the same as the traditional &'ndbm'& implementation.
1736 .next
1737 If the Berkeley package is used in its native mode, it operates on a single
1738 file called &_dbmfile_&; the programmer's interface is somewhat different to
1739 the traditional &'ndbm'& interface.
1740 .next
1741 To complicate things further, there are several very different versions of the
1742 Berkeley DB package. Version 1.85 was stable for a very long time, releases
1743 2.&'x'& and 3.&'x'& were current for a while, but the latest versions are now
1744 numbered 4.&'x'&. Maintenance of some of the earlier releases has ceased. All
1745 versions of Berkeley DB can be obtained from
1746 &url(http://www.sleepycat.com/).
1747 .next
1748 .cindex "&'tdb'& DBM library"
1749 Yet another DBM library, called &'tdb'&, is available from
1750 &url(http://download.sourceforge.net/tdb). It has its own interface, and also
1751 operates on a single file.
1752 .endlist
1754 .cindex "USE_DB"
1755 .cindex "DBM libraries" "configuration for building"
1756 Exim and its utilities can be compiled to use any of these interfaces. In order
1757 to use any version of the Berkeley DB package in native mode, you must set
1758 USE_DB in an appropriate configuration file (typically
1759 &_Local/Makefile_&). For example:
1760 .code
1761 USE_DB=yes
1762 .endd
1763 Similarly, for gdbm you set USE_GDBM, and for tdb you set USE_TDB. An
1764 error is diagnosed if you set more than one of these.
1766 At the lowest level, the build-time configuration sets none of these options,
1767 thereby assuming an interface of type (1). However, some operating system
1768 configuration files (for example, those for the BSD operating systems and
1769 Linux) assume type (4) by setting USE_DB as their default, and the
1770 configuration files for Cygwin set USE_GDBM. Anything you set in
1771 &_Local/Makefile_&, however, overrides these system defaults.
1773 As well as setting USE_DB, USE_GDBM, or USE_TDB, it may also be
1774 necessary to set DBMLIB, to cause inclusion of the appropriate library, as
1775 in one of these lines:
1776 .code
1777 DBMLIB = -ldb
1778 DBMLIB = -ltdb
1779 .endd
1780 Settings like that will work if the DBM library is installed in the standard
1781 place. Sometimes it is not, and the library's header file may also not be in
1782 the default path. You may need to set INCLUDE to specify where the header
1783 file is, and to specify the path to the library more fully in DBMLIB, as in
1784 this example:
1785 .code
1786 INCLUDE=-I/usr/local/include/db-4.1
1787 DBMLIB=/usr/local/lib/db-4.1/libdb.a
1788 .endd
1789 There is further detailed discussion about the various DBM libraries in the
1790 file &_doc/dbm.discuss.txt_& in the Exim distribution.
1794 .section "Pre-building configuration" "SECID25"
1795 .cindex "building Exim" "pre-building configuration"
1796 .cindex "configuration for building Exim"
1797 .cindex "&_Local/Makefile_&"
1798 .cindex "&_src/EDITME_&"
1799 Before building Exim, a local configuration file that specifies options
1800 independent of any operating system has to be created with the name
1801 &_Local/Makefile_&. A template for this file is supplied as the file
1802 &_src/EDITME_&, and it contains full descriptions of all the option settings
1803 therein. These descriptions are therefore not repeated here. If you are
1804 building Exim for the first time, the simplest thing to do is to copy
1805 &_src/EDITME_& to &_Local/Makefile_&, then read it and edit it appropriately.
1807 There are three settings that you must supply, because Exim will not build
1808 without them. They are the location of the run time configuration file
1809 (CONFIGURE_FILE), the directory in which Exim binaries will be installed
1810 (BIN_DIRECTORY), and the identity of the Exim user (EXIM_USER and
1811 maybe EXIM_GROUP as well). The value of CONFIGURE_FILE can in fact be
1812 a colon-separated list of file names; Exim uses the first of them that exists.
1814 There are a few other parameters that can be specified either at build time or
1815 at run time, to enable the same binary to be used on a number of different
1816 machines. However, if the locations of Exim's spool directory and log file
1817 directory (if not within the spool directory) are fixed, it is recommended that
1818 you specify them in &_Local/Makefile_& instead of at run time, so that errors
1819 detected early in Exim's execution (such as a malformed configuration file) can
1820 be logged.
1822 .cindex "content scanning" "specifying at build time"
1823 Exim's interfaces for calling virus and spam scanning software directly from
1824 access control lists are not compiled by default. If you want to include these
1825 facilities, you need to set
1826 .code
1828 .endd
1829 in your &_Local/Makefile_&. For details of the facilities themselves, see
1830 chapter &<<CHAPexiscan>>&.
1833 .cindex "&_Local/eximon.conf_&"
1834 .cindex "&_exim_monitor/EDITME_&"
1835 If you are going to build the Exim monitor, a similar configuration process is
1836 required. The file &_exim_monitor/EDITME_& must be edited appropriately for
1837 your installation and saved under the name &_Local/eximon.conf_&. If you are
1838 happy with the default settings described in &_exim_monitor/EDITME_&,
1839 &_Local/eximon.conf_& can be empty, but it must exist.
1841 This is all the configuration that is needed in straightforward cases for known
1842 operating systems. However, the building process is set up so that it is easy
1843 to override options that are set by default or by operating-system-specific
1844 configuration files, for example to change the name of the C compiler, which
1845 defaults to &%gcc%&. See section &<<SECToverride>>& below for details of how to
1846 do this.
1850 .section "Support for iconv()" "SECID26"
1851 .cindex "&[iconv()]& support"
1852 .cindex "RFC 2047"
1853 The contents of header lines in messages may be encoded according to the rules
1854 described RFC 2047. This makes it possible to transmit characters that are not
1855 in the ASCII character set, and to label them as being in a particular
1856 character set. When Exim is inspecting header lines by means of the &%$h_%&
1857 mechanism, it decodes them, and translates them into a specified character set
1858 (default ISO-8859-1). The translation is possible only if the operating system
1859 supports the &[iconv()]& function.
1861 However, some of the operating systems that supply &[iconv()]& do not support
1862 very many conversions. The GNU &%libiconv%& library (available from
1863 &url(http://www.gnu.org/software/libiconv/)) can be installed on such
1864 systems to remedy this deficiency, as well as on systems that do not supply
1865 &[iconv()]& at all. After installing &%libiconv%&, you should add
1866 .code
1867 HAVE_ICONV=yes
1868 .endd
1869 to your &_Local/Makefile_& and rebuild Exim.
1873 .section "Including TLS/SSL encryption support" "SECTinctlsssl"
1874 .cindex "TLS" "including support for TLS"
1875 .cindex "encryption" "including support for"
1876 .cindex "SUPPORT_TLS"
1877 .cindex "OpenSSL" "building Exim with"
1878 .cindex "GnuTLS" "building Exim with"
1879 Exim can be built to support encrypted SMTP connections, using the STARTTLS
1880 command as per RFC 2487. It can also support legacy clients that expect to
1881 start a TLS session immediately on connection to a non-standard port (see the
1882 &%tls_on_connect_ports%& runtime option and the &%-tls-on-connect%& command
1883 line option).
1885 If you want to build Exim with TLS support, you must first install either the
1886 OpenSSL or GnuTLS library. There is no cryptographic code in Exim itself for
1887 implementing SSL.
1889 If OpenSSL is installed, you should set
1890 .code
1891 SUPPORT_TLS=yes
1892 TLS_LIBS=-lssl -lcrypto
1893 .endd
1894 in &_Local/Makefile_&. You may also need to specify the locations of the
1895 OpenSSL library and include files. For example:
1896 .code
1897 SUPPORT_TLS=yes
1898 TLS_LIBS=-L/usr/local/openssl/lib -lssl -lcrypto
1899 TLS_INCLUDE=-I/usr/local/openssl/include/
1900 .endd
1901 .cindex "pkg-config" "OpenSSL"
1902 If you have &'pkg-config'& available, then instead you can just use:
1903 .code
1904 SUPPORT_TLS=yes
1905 USE_OPENSSL_PC=openssl
1906 .endd
1907 .cindex "USE_GNUTLS"
1908 If GnuTLS is installed, you should set
1909 .code
1910 SUPPORT_TLS=yes
1911 USE_GNUTLS=yes
1912 TLS_LIBS=-lgnutls -ltasn1 -lgcrypt
1913 .endd
1914 in &_Local/Makefile_&, and again you may need to specify the locations of the
1915 library and include files. For example:
1916 .code
1917 SUPPORT_TLS=yes
1918 USE_GNUTLS=yes
1919 TLS_LIBS=-L/usr/gnu/lib -lgnutls -ltasn1 -lgcrypt
1920 TLS_INCLUDE=-I/usr/gnu/include
1921 .endd
1922 .cindex "pkg-config" "GnuTLS"
1923 If you have &'pkg-config'& available, then instead you can just use:
1924 .code
1925 SUPPORT_TLS=yes
1926 USE_GNUTLS=yes
1927 USE_GNUTLS_PC=gnutls
1928 .endd
1930 You do not need to set TLS_INCLUDE if the relevant directory is already
1931 specified in INCLUDE. Details of how to configure Exim to make use of TLS are
1932 given in chapter &<<CHAPTLS>>&.
1937 .section "Use of tcpwrappers" "SECID27"
1939 .cindex "tcpwrappers, building Exim to support"
1940 .cindex "USE_TCP_WRAPPERS"
1942 .cindex "tcp_wrappers_daemon_name"
1943 Exim can be linked with the &'tcpwrappers'& library in order to check incoming
1944 SMTP calls using the &'tcpwrappers'& control files. This may be a convenient
1945 alternative to Exim's own checking facilities for installations that are
1946 already making use of &'tcpwrappers'& for other purposes. To do this, you
1947 should set USE_TCP_WRAPPERS in &_Local/Makefile_&, arrange for the file
1948 &_tcpd.h_& to be available at compile time, and also ensure that the library
1949 &_libwrap.a_& is available at link time, typically by including &%-lwrap%& in
1950 EXTRALIBS_EXIM. For example, if &'tcpwrappers'& is installed in &_/usr/local_&,
1951 you might have
1952 .code
1954 CFLAGS=-O -I/usr/local/include
1955 EXTRALIBS_EXIM=-L/usr/local/lib -lwrap
1956 .endd
1957 in &_Local/Makefile_&. The daemon name to use in the &'tcpwrappers'& control
1958 files is &"exim"&. For example, the line
1959 .code
1960 exim : LOCAL 192.168.1. .friendly.domain.example
1961 .endd
1962 in your &_/etc/hosts.allow_& file allows connections from the local host, from
1963 the subnet, and from all hosts in &'friendly.domain.example'&.
1964 All other connections are denied. The daemon name used by &'tcpwrappers'&
1965 can be changed at build time by setting TCP_WRAPPERS_DAEMON_NAME in
1966 &_Local/Makefile_&, or by setting tcp_wrappers_daemon_name in the
1967 configure file. Consult the &'tcpwrappers'& documentation for
1968 further details.
1971 .section "Including support for IPv6" "SECID28"
1972 .cindex "IPv6" "including support for"
1973 Exim contains code for use on systems that have IPv6 support. Setting
1974 &`HAVE_IPV6=YES`& in &_Local/Makefile_& causes the IPv6 code to be included;
1975 it may also be necessary to set IPV6_INCLUDE and IPV6_LIBS on systems
1976 where the IPv6 support is not fully integrated into the normal include and
1977 library files.
1979 Two different types of DNS record for handling IPv6 addresses have been
1980 defined. AAAA records (analogous to A records for IPv4) are in use, and are
1981 currently seen as the mainstream. Another record type called A6 was proposed
1982 as better than AAAA because it had more flexibility. However, it was felt to be
1983 over-complex, and its status was reduced to &"experimental"&. It is not known
1984 if anyone is actually using A6 records. Exim has support for A6 records, but
1985 this is included only if you set &`SUPPORT_A6=YES`& in &_Local/Makefile_&. The
1986 support has not been tested for some time.
1990 .section "Dynamically loaded lookup module support" "SECTdynamicmodules"
1991 .cindex "lookup modules"
1992 .cindex "dynamic modules"
1993 .cindex ".so building"
1994 On some platforms, Exim supports not compiling all lookup types directly into
1995 the main binary, instead putting some into external modules which can be loaded
1996 on demand.
1997 This permits packagers to build Exim with support for lookups with extensive
1998 library dependencies without requiring all users to install all of those
1999 dependencies.
2000 Most, but not all, lookup types can be built this way.
2002 Set &`LOOKUP_MODULE_DIR`& to the directory into which the modules will be
2003 installed; Exim will only load modules from that directory, as a security
2004 measure. You will need to set &`CFLAGS_DYNAMIC`& if not already defined
2005 for your OS; see &_OS/Makefile-Linux_& for an example.
2006 Some other requirements for adjusting &`EXTRALIBS`& may also be necessary,
2007 see &_src/EDITME_& for details.
2009 Then, for each module to be loaded dynamically, define the relevant
2010 &`LOOKUP_`&<&'lookup_type'&> flags to have the value "2" instead of "yes".
2011 For example, this will build in lsearch but load sqlite and mysql support
2012 on demand:
2013 .code
2017 .endd
2020 .section "The building process" "SECID29"
2021 .cindex "build directory"
2022 Once &_Local/Makefile_& (and &_Local/eximon.conf_&, if required) have been
2023 created, run &'make'& at the top level. It determines the architecture and
2024 operating system types, and creates a build directory if one does not exist.
2025 For example, on a Sun system running Solaris 8, the directory
2026 &_build-SunOS5-5.8-sparc_& is created.
2027 .cindex "symbolic link" "to source files"
2028 Symbolic links to relevant source files are installed in the build directory.
2030 &*Warning*&: The &%-j%& (parallel) flag must not be used with &'make'&; the
2031 building process fails if it is set.
2033 If this is the first time &'make'& has been run, it calls a script that builds
2034 a make file inside the build directory, using the configuration files from the
2035 &_Local_& directory. The new make file is then passed to another instance of
2036 &'make'&. This does the real work, building a number of utility scripts, and
2037 then compiling and linking the binaries for the Exim monitor (if configured), a
2038 number of utility programs, and finally Exim itself. The command &`make
2039 makefile`& can be used to force a rebuild of the make file in the build
2040 directory, should this ever be necessary.
2042 If you have problems building Exim, check for any comments there may be in the
2043 &_README_& file concerning your operating system, and also take a look at the
2044 FAQ, where some common problems are covered.
2048 .section 'Output from &"make"&' "SECID283"
2049 The output produced by the &'make'& process for compile lines is often very
2050 unreadable, because these lines can be very long. For this reason, the normal
2051 output is suppressed by default, and instead output similar to that which
2052 appears when compiling the 2.6 Linux kernel is generated: just a short line for
2053 each module that is being compiled or linked. However, it is still possible to
2054 get the full output, by calling &'make'& like this:
2055 .code
2056 FULLECHO='' make -e
2057 .endd
2058 The value of FULLECHO defaults to &"@"&, the flag character that suppresses
2059 command reflection in &'make'&. When you ask for the full output, it is
2060 given in addition to the short output.
2064 .section "Overriding build-time options for Exim" "SECToverride"
2065 .cindex "build-time options, overriding"
2066 The main make file that is created at the beginning of the building process
2067 consists of the concatenation of a number of files which set configuration
2068 values, followed by a fixed set of &'make'& instructions. If a value is set
2069 more than once, the last setting overrides any previous ones. This provides a
2070 convenient way of overriding defaults. The files that are concatenated are, in
2071 order:
2072 .display
2073 &_OS/Makefile-Default_&
2074 &_OS/Makefile-_&<&'ostype'&>
2075 &_Local/Makefile_&
2076 &_Local/Makefile-_&<&'ostype'&>
2077 &_Local/Makefile-_&<&'archtype'&>
2078 &_Local/Makefile-_&<&'ostype'&>-<&'archtype'&>
2079 &_OS/Makefile-Base_&
2080 .endd
2081 .cindex "&_Local/Makefile_&"
2082 .cindex "building Exim" "operating system type"
2083 .cindex "building Exim" "architecture type"
2084 where <&'ostype'&> is the operating system type and <&'archtype'&> is the
2085 architecture type. &_Local/Makefile_& is required to exist, and the building
2086 process fails if it is absent. The other three &_Local_& files are optional,
2087 and are often not needed.
2089 The values used for <&'ostype'&> and <&'archtype'&> are obtained from scripts
2090 called &_scripts/os-type_& and &_scripts/arch-type_& respectively. If either of
2091 the environment variables EXIM_OSTYPE or EXIM_ARCHTYPE is set, their
2092 values are used, thereby providing a means of forcing particular settings.
2093 Otherwise, the scripts try to get values from the &%uname%& command. If this
2094 fails, the shell variables OSTYPE and ARCHTYPE are inspected. A number
2095 of &'ad hoc'& transformations are then applied, to produce the standard names
2096 that Exim expects. You can run these scripts directly from the shell in order
2097 to find out what values are being used on your system.
2100 &_OS/Makefile-Default_& contains comments about the variables that are set
2101 therein. Some (but not all) are mentioned below. If there is something that
2102 needs changing, review the contents of this file and the contents of the make
2103 file for your operating system (&_OS/Makefile-<ostype>_&) to see what the
2104 default values are.
2107 .cindex "building Exim" "overriding default settings"
2108 If you need to change any of the values that are set in &_OS/Makefile-Default_&
2109 or in &_OS/Makefile-<ostype>_&, or to add any new definitions, you do not
2110 need to change the original files. Instead, you should make the changes by
2111 putting the new values in an appropriate &_Local_& file. For example,
2112 .cindex "Tru64-Unix build-time settings"
2113 when building Exim in many releases of the Tru64-Unix (formerly Digital UNIX,
2114 formerly DEC-OSF1) operating system, it is necessary to specify that the C
2115 compiler is called &'cc'& rather than &'gcc'&. Also, the compiler must be
2116 called with the option &%-std1%&, to make it recognize some of the features of
2117 Standard C that Exim uses. (Most other compilers recognize Standard C by
2118 default.) To do this, you should create a file called &_Local/Makefile-OSF1_&
2119 containing the lines
2120 .code
2121 CC=cc
2122 CFLAGS=-std1
2123 .endd
2124 If you are compiling for just one operating system, it may be easier to put
2125 these lines directly into &_Local/Makefile_&.
2127 Keeping all your local configuration settings separate from the distributed
2128 files makes it easy to transfer them to new versions of Exim simply by copying
2129 the contents of the &_Local_& directory.
2132 .cindex "NIS lookup type" "including support for"
2133 .cindex "NIS+ lookup type" "including support for"
2134 .cindex "LDAP" "including support for"
2135 .cindex "lookup" "inclusion in binary"
2136 Exim contains support for doing LDAP, NIS, NIS+, and other kinds of file
2137 lookup, but not all systems have these components installed, so the default is
2138 not to include the relevant code in the binary. All the different kinds of file
2139 and database lookup that Exim supports are implemented as separate code modules
2140 which are included only if the relevant compile-time options are set. In the
2141 case of LDAP, NIS, and NIS+, the settings for &_Local/Makefile_& are:
2142 .code
2143 LOOKUP_LDAP=yes
2144 LOOKUP_NIS=yes
2146 .endd
2147 and similar settings apply to the other lookup types. They are all listed in
2148 &_src/EDITME_&. In many cases the relevant include files and interface
2149 libraries need to be installed before compiling Exim.
2150 .cindex "cdb" "including support for"
2151 However, there are some optional lookup types (such as cdb) for which
2152 the code is entirely contained within Exim, and no external include
2153 files or libraries are required. When a lookup type is not included in the
2154 binary, attempts to configure Exim to use it cause run time configuration
2155 errors.
2157 .cindex "pkg-config" "lookups"
2158 .cindex "pkg-config" "authenticators"
2159 Many systems now use a tool called &'pkg-config'& to encapsulate information
2160 about how to compile against a library; Exim has some initial support for
2161 being able to use pkg-config for lookups and authenticators. For any given
2162 makefile variable which starts &`LOOKUP_`& or &`AUTH_`&, you can add a new
2163 variable with the &`_PC`& suffix in the name and assign as the value the
2164 name of the package to be queried. The results of querying via the
2165 &'pkg-config'& command will be added to the appropriate Makefile variables
2166 with &`+=`& directives, so your version of &'make'& will need to support that
2167 syntax. For instance:
2168 .code
2170 LOOKUP_SQLITE_PC=sqlite3
2171 AUTH_GSASL=yes
2172 AUTH_GSASL_PC=libgsasl
2174 AUTH_HEIMDAL_GSSAPI_PC=heimdal-gssapi
2175 .endd
2177 .cindex "Perl" "including support for"
2178 Exim can be linked with an embedded Perl interpreter, allowing Perl
2179 subroutines to be called during string expansion. To enable this facility,
2180 .code
2181 EXIM_PERL=perl.o
2182 .endd
2183 must be defined in &_Local/Makefile_&. Details of this facility are given in
2184 chapter &<<CHAPperl>>&.
2186 .cindex "X11 libraries, location of"
2187 The location of the X11 libraries is something that varies a lot between
2188 operating systems, and there may be different versions of X11 to cope
2189 with. Exim itself makes no use of X11, but if you are compiling the Exim
2190 monitor, the X11 libraries must be available.
2191 The following three variables are set in &_OS/Makefile-Default_&:
2192 .code
2193 X11=/usr/X11R6
2194 XINCLUDE=-I$(X11)/include
2195 XLFLAGS=-L$(X11)/lib
2196 .endd
2197 These are overridden in some of the operating-system configuration files. For
2198 example, in &_OS/Makefile-SunOS5_& there is
2199 .code
2200 X11=/usr/openwin
2201 XINCLUDE=-I$(X11)/include
2202 XLFLAGS=-L$(X11)/lib -R$(X11)/lib
2203 .endd
2204 If you need to override the default setting for your operating system, place a
2205 definition of all three of these variables into your
2206 &_Local/Makefile-<ostype>_& file.
2208 .cindex "EXTRALIBS"
2209 If you need to add any extra libraries to the link steps, these can be put in a
2210 variable called EXTRALIBS, which appears in all the link commands, but by
2211 default is not defined. In contrast, EXTRALIBS_EXIM is used only on the
2212 command for linking the main Exim binary, and not for any associated utilities.
2214 .cindex "DBM libraries" "configuration for building"
2215 There is also DBMLIB, which appears in the link commands for binaries that
2216 use DBM functions (see also section &<<SECTdb>>&). Finally, there is
2217 EXTRALIBS_EXIMON, which appears only in the link step for the Exim monitor
2218 binary, and which can be used, for example, to include additional X11
2219 libraries.
2221 .cindex "configuration file" "editing"
2222 The make file copes with rebuilding Exim correctly if any of the configuration
2223 files are edited. However, if an optional configuration file is deleted, it is
2224 necessary to touch the associated non-optional file (that is,
2225 &_Local/Makefile_& or &_Local/eximon.conf_&) before rebuilding.
2228 .section "OS-specific header files" "SECID30"
2229 .cindex "&_os.h_&"
2230 .cindex "building Exim" "OS-specific C header files"
2231 The &_OS_& directory contains a number of files with names of the form
2232 &_os.h-<ostype>_&. These are system-specific C header files that should not
2233 normally need to be changed. There is a list of macro settings that are
2234 recognized in the file &_OS/os.configuring_&, which should be consulted if you
2235 are porting Exim to a new operating system.
2239 .section "Overriding build-time options for the monitor" "SECID31"
2240 .cindex "building Eximon"
2241 A similar process is used for overriding things when building the Exim monitor,
2242 where the files that are involved are
2243 .display
2244 &_OS/eximon.conf-Default_&
2245 &_OS/eximon.conf-_&<&'ostype'&>
2246 &_Local/eximon.conf_&
2247 &_Local/eximon.conf-_&<&'ostype'&>
2248 &_Local/eximon.conf-_&<&'archtype'&>
2249 &_Local/eximon.conf-_&<&'ostype'&>-<&'archtype'&>
2250 .endd
2251 .cindex "&_Local/eximon.conf_&"
2252 As with Exim itself, the final three files need not exist, and in this case the
2253 &_OS/eximon.conf-<ostype>_& file is also optional. The default values in
2254 &_OS/eximon.conf-Default_& can be overridden dynamically by setting environment
2255 variables of the same name, preceded by EXIMON_. For example, setting
2256 EXIMON_LOG_DEPTH in the environment overrides the value of
2257 LOG_DEPTH at run time.
2258 .ecindex IIDbuex
2261 .section "Installing Exim binaries and scripts" "SECID32"
2262 .cindex "installing Exim"
2263 .cindex "BIN_DIRECTORY"
2264 The command &`make install`& runs the &(exim_install)& script with no
2265 arguments. The script copies binaries and utility scripts into the directory
2266 whose name is specified by the BIN_DIRECTORY setting in &_Local/Makefile_&.
2267 .cindex "setuid" "installing Exim with"
2268 The install script copies files only if they are newer than the files they are
2269 going to replace. The Exim binary is required to be owned by root and have the
2270 &'setuid'& bit set, for normal configurations. Therefore, you must run &`make
2271 install`& as root so that it can set up the Exim binary in this way. However, in
2272 some special situations (for example, if a host is doing no local deliveries)
2273 it may be possible to run Exim without making the binary setuid root (see
2274 chapter &<<CHAPsecurity>>& for details).
2276 .cindex "CONFIGURE_FILE"
2277 Exim's run time configuration file is named by the CONFIGURE_FILE setting
2278 in &_Local/Makefile_&. If this names a single file, and the file does not
2279 exist, the default configuration file &_src/configure.default_& is copied there
2280 by the installation script. If a run time configuration file already exists, it
2281 is left alone. If CONFIGURE_FILE is a colon-separated list, naming several
2282 alternative files, no default is installed.
2284 .cindex "system aliases file"
2285 .cindex "&_/etc/aliases_&"
2286 One change is made to the default configuration file when it is installed: the
2287 default configuration contains a router that references a system aliases file.
2288 The path to this file is set to the value specified by
2289 SYSTEM_ALIASES_FILE in &_Local/Makefile_& (&_/etc/aliases_& by default).
2290 If the system aliases file does not exist, the installation script creates it,
2291 and outputs a comment to the user.
2293 The created file contains no aliases, but it does contain comments about the
2294 aliases a site should normally have. Mail aliases have traditionally been
2295 kept in &_/etc/aliases_&. However, some operating systems are now using
2296 &_/etc/mail/aliases_&. You should check if yours is one of these, and change
2297 Exim's configuration if necessary.
2299 The default configuration uses the local host's name as the only local domain,
2300 and is set up to do local deliveries into the shared directory &_/var/mail_&,
2301 running as the local user. System aliases and &_.forward_& files in users' home
2302 directories are supported, but no NIS or NIS+ support is configured. Domains
2303 other than the name of the local host are routed using the DNS, with delivery
2304 over SMTP.
2306 It is possible to install Exim for special purposes (such as building a binary
2307 distribution) in a private part of the file system. You can do this by a
2308 command such as
2309 .code
2310 make DESTDIR=/some/directory/ install
2311 .endd
2312 This has the effect of pre-pending the specified directory to all the file
2313 paths, except the name of the system aliases file that appears in the default
2314 configuration. (If a default alias file is created, its name &'is'& modified.)
2315 For backwards compatibility, ROOT is used if DESTDIR is not set,
2316 but this usage is deprecated.
2318 .cindex "installing Exim" "what is not installed"
2319 Running &'make install'& does not copy the Exim 4 conversion script
2320 &'convert4r4'&. You will probably run this only once if you are
2321 upgrading from Exim 3. None of the documentation files in the &_doc_&
2322 directory are copied, except for the info files when you have set
2323 INFO_DIRECTORY, as described in section &<<SECTinsinfdoc>>& below.
2325 For the utility programs, old versions are renamed by adding the suffix &_.O_&
2326 to their names. The Exim binary itself, however, is handled differently. It is
2327 installed under a name that includes the version number and the compile number,
2328 for example &_exim-&version()-1_&. The script then arranges for a symbolic link
2329 called &_exim_& to point to the binary. If you are updating a previous version
2330 of Exim, the script takes care to ensure that the name &_exim_& is never absent
2331 from the directory (as seen by other processes).
2333 .cindex "installing Exim" "testing the script"
2334 If you want to see what the &'make install'& will do before running it for
2335 real, you can pass the &%-n%& option to the installation script by this
2336 command:
2337 .code
2338 make INSTALL_ARG=-n install
2339 .endd
2340 The contents of the variable INSTALL_ARG are passed to the installation
2341 script. You do not need to be root to run this test. Alternatively, you can run
2342 the installation script directly, but this must be from within the build
2343 directory. For example, from the top-level Exim directory you could use this
2344 command:
2345 .code
2346 (cd build-SunOS5-5.5.1-sparc; ../scripts/exim_install -n)
2347 .endd
2348 .cindex "installing Exim" "install script options"
2349 There are two other options that can be supplied to the installation script.
2351 .ilist
2352 &%-no_chown%& bypasses the call to change the owner of the installed binary
2353 to root, and the call to make it a setuid binary.
2354 .next
2355 &%-no_symlink%& bypasses the setting up of the symbolic link &_exim_& to the
2356 installed binary.
2357 .endlist
2359 INSTALL_ARG can be used to pass these options to the script. For example:
2360 .code
2361 make INSTALL_ARG=-no_symlink install
2362 .endd
2363 The installation script can also be given arguments specifying which files are
2364 to be copied. For example, to install just the Exim binary, and nothing else,
2365 without creating the symbolic link, you could use:
2366 .code
2367 make INSTALL_ARG='-no_symlink exim' install
2368 .endd
2372 .section "Installing info documentation" "SECTinsinfdoc"
2373 .cindex "installing Exim" "&'info'& documentation"
2374 Not all systems use the GNU &'info'& system for documentation, and for this
2375 reason, the Texinfo source of Exim's documentation is not included in the main
2376 distribution. Instead it is available separately from the ftp site (see section
2377 &<<SECTavail>>&).
2379 If you have defined INFO_DIRECTORY in &_Local/Makefile_& and the Texinfo
2380 source of the documentation is found in the source tree, running &`make
2381 install`& automatically builds the info files and installs them.
2385 .section "Setting up the spool directory" "SECID33"
2386 .cindex "spool directory" "creating"
2387 When it starts up, Exim tries to create its spool directory if it does not
2388 exist. The Exim uid and gid are used for the owner and group of the spool
2389 directory. Sub-directories are automatically created in the spool directory as
2390 necessary.
2395 .section "Testing" "SECID34"
2396 .cindex "testing" "installation"
2397 Having installed Exim, you can check that the run time configuration file is
2398 syntactically valid by running the following command, which assumes that the
2399 Exim binary directory is within your PATH environment variable:
2400 .code
2401 exim -bV
2402 .endd
2403 If there are any errors in the configuration file, Exim outputs error messages.
2404 Otherwise it outputs the version number and build date,
2405 the DBM library that is being used, and information about which drivers and
2406 other optional code modules are included in the binary.
2407 Some simple routing tests can be done by using the address testing option. For
2408 example,
2409 .display
2410 &`exim -bt`& <&'local username'&>
2411 .endd
2412 should verify that it recognizes a local mailbox, and
2413 .display
2414 &`exim -bt`& <&'remote address'&>
2415 .endd
2416 a remote one. Then try getting it to deliver mail, both locally and remotely.
2417 This can be done by passing messages directly to Exim, without going through a
2418 user agent. For example:
2419 .code
2420 exim -v postmaster@your.domain.example
2421 From: user@your.domain.example
2422 To: postmaster@your.domain.example
2423 Subject: Testing Exim
2425 This is a test message.
2426 ^D
2427 .endd
2428 The &%-v%& option causes Exim to output some verification of what it is doing.
2429 In this case you should see copies of three log lines, one for the message's
2430 arrival, one for its delivery, and one containing &"Completed"&.
2432 .cindex "delivery" "problems with"
2433 If you encounter problems, look at Exim's log files (&'mainlog'& and
2434 &'paniclog'&) to see if there is any relevant information there. Another source
2435 of information is running Exim with debugging turned on, by specifying the
2436 &%-d%& option. If a message is stuck on Exim's spool, you can force a delivery
2437 with debugging turned on by a command of the form
2438 .display
2439 &`exim -d -M`& <&'exim-message-id'&>
2440 .endd
2441 You must be root or an &"admin user"& in order to do this. The &%-d%& option
2442 produces rather a lot of output, but you can cut this down to specific areas.
2443 For example, if you use &%-d-all+route%& only the debugging information
2444 relevant to routing is included. (See the &%-d%& option in chapter
2445 &<<CHAPcommandline>>& for more details.)
2447 .cindex '&"sticky"& bit'
2448 .cindex "lock files"
2449 One specific problem that has shown up on some sites is the inability to do
2450 local deliveries into a shared mailbox directory, because it does not have the
2451 &"sticky bit"& set on it. By default, Exim tries to create a lock file before
2452 writing to a mailbox file, and if it cannot create the lock file, the delivery
2453 is deferred. You can get round this either by setting the &"sticky bit"& on the
2454 directory, or by setting a specific group for local deliveries and allowing
2455 that group to create files in the directory (see the comments above the
2456 &(local_delivery)& transport in the default configuration file). Another
2457 approach is to configure Exim not to use lock files, but just to rely on
2458 &[fcntl()]& locking instead. However, you should do this only if all user
2459 agents also use &[fcntl()]& locking. For further discussion of locking issues,
2460 see chapter &<<CHAPappendfile>>&.
2462 One thing that cannot be tested on a system that is already running an MTA is
2463 the receipt of incoming SMTP mail on the standard SMTP port. However, the
2464 &%-oX%& option can be used to run an Exim daemon that listens on some other
2465 port, or &'inetd'& can be used to do this. The &%-bh%& option and the
2466 &'exim_checkaccess'& utility can be used to check out policy controls on
2467 incoming SMTP mail.
2469 Testing a new version on a system that is already running Exim can most easily
2470 be done by building a binary with a different CONFIGURE_FILE setting. From
2471 within the run time configuration, all other file and directory names
2472 that Exim uses can be altered, in order to keep it entirely clear of the
2473 production version.
2476 .section "Replacing another MTA with Exim" "SECID35"
2477 .cindex "replacing another MTA"
2478 Building and installing Exim for the first time does not of itself put it in
2479 general use. The name by which the system's MTA is called by mail user agents
2480 is either &_/usr/sbin/sendmail_&, or &_/usr/lib/sendmail_& (depending on the
2481 operating system), and it is necessary to make this name point to the &'exim'&
2482 binary in order to get the user agents to pass messages to Exim. This is
2483 normally done by renaming any existing file and making &_/usr/sbin/sendmail_&
2484 or &_/usr/lib/sendmail_&
2485 .cindex "symbolic link" "to &'exim'& binary"
2486 a symbolic link to the &'exim'& binary. It is a good idea to remove any setuid
2487 privilege and executable status from the old MTA. It is then necessary to stop
2488 and restart the mailer daemon, if one is running.
2490 .cindex "FreeBSD, MTA indirection"
2491 .cindex "&_/etc/mail/mailer.conf_&"
2492 Some operating systems have introduced alternative ways of switching MTAs. For
2493 example, if you are running FreeBSD, you need to edit the file
2494 &_/etc/mail/mailer.conf_& instead of setting up a symbolic link as just
2495 described. A typical example of the contents of this file for running Exim is
2496 as follows:
2497 .code
2498 sendmail /usr/exim/bin/exim
2499 send-mail /usr/exim/bin/exim
2500 mailq /usr/exim/bin/exim -bp
2501 newaliases /usr/bin/true
2502 .endd
2503 Once you have set up the symbolic link, or edited &_/etc/mail/mailer.conf_&,
2504 your Exim installation is &"live"&. Check it by sending a message from your
2505 favourite user agent.
2507 You should consider what to tell your users about the change of MTA. Exim may
2508 have different capabilities to what was previously running, and there are
2509 various operational differences such as the text of messages produced by
2510 command line options and in bounce messages. If you allow your users to make
2511 use of Exim's filtering capabilities, you should make the document entitled
2512 &'Exim's interface to mail filtering'& available to them.
2516 .section "Upgrading Exim" "SECID36"
2517 .cindex "upgrading Exim"
2518 If you are already running Exim on your host, building and installing a new
2519 version automatically makes it available to MUAs, or any other programs that
2520 call the MTA directly. However, if you are running an Exim daemon, you do need
2521 to send it a HUP signal, to make it re-execute itself, and thereby pick up the
2522 new binary. You do not need to stop processing mail in order to install a new
2523 version of Exim. The install script does not modify an existing runtime
2524 configuration file.
2529 .section "Stopping the Exim daemon on Solaris" "SECID37"
2530 .cindex "Solaris" "stopping Exim on"
2531 The standard command for stopping the mailer daemon on Solaris is
2532 .code
2533 /etc/init.d/sendmail stop
2534 .endd
2535 If &_/usr/lib/sendmail_& has been turned into a symbolic link, this script
2536 fails to stop Exim because it uses the command &'ps -e'& and greps the output
2537 for the text &"sendmail"&; this is not present because the actual program name
2538 (that is, &"exim"&) is given by the &'ps'& command with these options. A
2539 solution is to replace the line that finds the process id with something like
2540 .code
2541 pid=`cat /var/spool/exim/exim-daemon.pid`
2542 .endd
2543 to obtain the daemon's pid directly from the file that Exim saves it in.
2545 Note, however, that stopping the daemon does not &"stop Exim"&. Messages can
2546 still be received from local processes, and if automatic delivery is configured
2547 (the normal case), deliveries will still occur.
2552 . ////////////////////////////////////////////////////////////////////////////
2553 . ////////////////////////////////////////////////////////////////////////////
2555 .chapter "The Exim command line" "CHAPcommandline"
2556 .scindex IIDclo1 "command line" "options"
2557 .scindex IIDclo2 "options" "command line"
2558 Exim's command line takes the standard Unix form of a sequence of options,
2559 each starting with a hyphen character, followed by a number of arguments. The
2560 options are compatible with the main options of Sendmail, and there are also
2561 some additional options, some of which are compatible with Smail 3. Certain
2562 combinations of options do not make sense, and provoke an error if used.
2563 The form of the arguments depends on which options are set.
2566 .section "Setting options by program name" "SECID38"
2567 .cindex "&'mailq'&"
2568 If Exim is called under the name &'mailq'&, it behaves as if the option &%-bp%&
2569 were present before any other options.
2570 The &%-bp%& option requests a listing of the contents of the mail queue on the
2571 standard output.
2572 This feature is for compatibility with some systems that contain a command of
2573 that name in one of the standard libraries, symbolically linked to
2574 &_/usr/sbin/sendmail_& or &_/usr/lib/sendmail_&.
2576 .cindex "&'rsmtp'&"
2577 If Exim is called under the name &'rsmtp'& it behaves as if the option &%-bS%&
2578 were present before any other options, for compatibility with Smail. The
2579 &%-bS%& option is used for reading in a number of messages in batched SMTP
2580 format.
2582 .cindex "&'rmail'&"
2583 If Exim is called under the name &'rmail'& it behaves as if the &%-i%& and
2584 &%-oee%& options were present before any other options, for compatibility with
2585 Smail. The name &'rmail'& is used as an interface by some UUCP systems.
2587 .cindex "&'runq'&"
2588 .cindex "queue runner"
2589 If Exim is called under the name &'runq'& it behaves as if the option &%-q%&
2590 were present before any other options, for compatibility with Smail. The &%-q%&
2591 option causes a single queue runner process to be started.
2593 .cindex "&'newaliases'&"
2594 .cindex "alias file" "building"
2595 .cindex "Sendmail compatibility" "calling Exim as &'newaliases'&"
2596 If Exim is called under the name &'newaliases'& it behaves as if the option
2597 &%-bi%& were present before any other options, for compatibility with Sendmail.
2598 This option is used for rebuilding Sendmail's alias file. Exim does not have
2599 the concept of a single alias file, but can be configured to run a given
2600 command if called with the &%-bi%& option.
2603 .section "Trusted and admin users" "SECTtrustedadmin"
2604 Some Exim options are available only to &'trusted users'& and others are
2605 available only to &'admin users'&. In the description below, the phrases &"Exim
2606 user"& and &"Exim group"& mean the user and group defined by EXIM_USER and
2607 EXIM_GROUP in &_Local/Makefile_& or set by the &%exim_user%& and
2608 &%exim_group%& options. These do not necessarily have to use the name &"exim"&.
2610 .ilist
2611 .cindex "trusted users" "definition of"
2612 .cindex "user" "trusted definition of"
2613 The trusted users are root, the Exim user, any user listed in the
2614 &%trusted_users%& configuration option, and any user whose current group or any
2615 supplementary group is one of those listed in the &%trusted_groups%&
2616 configuration option. Note that the Exim group is not automatically trusted.
2618 .cindex '&"From"& line'
2619 .cindex "envelope sender"
2620 Trusted users are always permitted to use the &%-f%& option or a leading
2621 &"From&~"& line to specify the envelope sender of a message that is passed to
2622 Exim through the local interface (see the &%-bm%& and &%-f%& options below).
2623 See the &%untrusted_set_sender%& option for a way of permitting non-trusted
2624 users to set envelope senders.
2626 .cindex "&'From:'& header line"
2627 .cindex "&'Sender:'& header line"
2628 For a trusted user, there is never any check on the contents of the &'From:'&
2629 header line, and a &'Sender:'& line is never added. Furthermore, any existing
2630 &'Sender:'& line in incoming local (non-TCP/IP) messages is not removed.
2632 Trusted users may also specify a host name, host address, interface address,
2633 protocol name, ident value, and authentication data when submitting a message
2634 locally. Thus, they are able to insert messages into Exim's queue locally that
2635 have the characteristics of messages received from a remote host. Untrusted
2636 users may in some circumstances use &%-f%&, but can never set the other values
2637 that are available to trusted users.
2638 .next
2639 .cindex "user" "admin definition of"
2640 .cindex "admin user" "definition of"
2641 The admin users are root, the Exim user, and any user that is a member of the
2642 Exim group or of any group listed in the &%admin_groups%& configuration option.
2643 The current group does not have to be one of these groups.
2645 Admin users are permitted to list the queue, and to carry out certain
2646 operations on messages, for example, to force delivery failures. It is also
2647 necessary to be an admin user in order to see the full information provided by
2648 the Exim monitor, and full debugging output.
2650 By default, the use of the &%-M%&, &%-q%&, &%-R%&, and &%-S%& options to cause
2651 Exim to attempt delivery of messages on its queue is restricted to admin users.
2652 However, this restriction can be relaxed by setting the &%prod_requires_admin%&
2653 option false (that is, specifying &%no_prod_requires_admin%&).
2655 Similarly, the use of the &%-bp%& option to list all the messages in the queue
2656 is restricted to admin users unless &%queue_list_requires_admin%& is set
2657 false.
2658 .endlist
2661 &*Warning*&: If you configure your system so that admin users are able to
2662 edit Exim's configuration file, you are giving those users an easy way of
2663 getting root. There is further discussion of this issue at the start of chapter
2664 &<<CHAPconf>>&.
2669 .section "Command line options" "SECID39"
2670 Exim's command line options are described in alphabetical order below. If none
2671 of the options that specifies a specific action (such as starting the daemon or
2672 a queue runner, or testing an address, or receiving a message in a specific
2673 format, or listing the queue) are present, and there is at least one argument
2674 on the command line, &%-bm%& (accept a local message on the standard input,
2675 with the arguments specifying the recipients) is assumed. Otherwise, Exim
2676 outputs a brief message about itself and exits.
2678 . ////////////////////////////////////////////////////////////////////////////
2679 . Insert a stylized XML comment here, to identify the start of the command line
2680 . options. This is for the benefit of the Perl script that automatically
2681 . creates a man page for the options.
2682 . ////////////////////////////////////////////////////////////////////////////
2684 .literal xml
2685 <!-- === Start of command line options === -->
2686 .literal off
2689 .vlist
2690 .vitem &%--%&
2691 .oindex "--"
2692 .cindex "options" "command line; terminating"
2693 This is a pseudo-option whose only purpose is to terminate the options and
2694 therefore to cause subsequent command line items to be treated as arguments
2695 rather than options, even if they begin with hyphens.
2697 .vitem &%--help%&
2698 .oindex "&%--help%&"
2699 This option causes Exim to output a few sentences stating what it is.
2700 The same output is generated if the Exim binary is called with no options and
2701 no arguments.
2703 .vitem &%--version%&
2704 .oindex "&%--version%&"
2705 This option is an alias for &%-bV%& and causes version information to be
2706 displayed.
2708 .new
2709 .vitem &%-Ac%& &&&
2710 &%-Am%&
2711 .oindex "&%-Ac%&"
2712 .oindex "&%-Am%&"
2713 These options are used by Sendmail for selecting configuration files and are
2714 ignored by Exim.
2715 .wen
2717 .vitem &%-B%&<&'type'&>
2718 .oindex "&%-B%&"
2719 .cindex "8-bit characters"
2720 .cindex "Sendmail compatibility" "8-bit characters"
2721 This is a Sendmail option for selecting 7 or 8 bit processing. Exim is 8-bit
2722 clean; it ignores this option.
2724 .vitem &%-bd%&
2725 .oindex "&%-bd%&"
2726 .cindex "daemon"
2727 .cindex "SMTP" "listener"
2728 .cindex "queue runner"
2729 This option runs Exim as a daemon, awaiting incoming SMTP connections. Usually
2730 the &%-bd%& option is combined with the &%-q%&<&'time'&> option, to specify
2731 that the daemon should also initiate periodic queue runs.
2733 The &%-bd%& option can be used only by an admin user. If either of the &%-d%&
2734 (debugging) or &%-v%& (verifying) options are set, the daemon does not
2735 disconnect from the controlling terminal. When running this way, it can be
2736 stopped by pressing ctrl-C.
2738 By default, Exim listens for incoming connections to the standard SMTP port on
2739 all the host's running interfaces. However, it is possible to listen on other
2740 ports, on multiple ports, and only on specific interfaces. Chapter
2741 &<<CHAPinterfaces>>& contains a description of the options that control this.
2743 When a listening daemon
2744 .cindex "daemon" "process id (pid)"
2745 .cindex "pid (process id)" "of daemon"
2746 is started without the use of &%-oX%& (that is, without overriding the normal
2747 configuration), it writes its process id to a file called &_exim-daemon.pid_&
2748 in Exim's spool directory. This location can be overridden by setting
2749 PID_FILE_PATH in &_Local/Makefile_&. The file is written while Exim is still
2750 running as root.
2752 When &%-oX%& is used on the command line to start a listening daemon, the
2753 process id is not written to the normal pid file path. However, &%-oP%& can be
2754 used to specify a path on the command line if a pid file is required.
2756 The SIGHUP signal
2757 .cindex "SIGHUP"
2758 .cindex "daemon" "restarting"
2759 can be used to cause the daemon to re-execute itself. This should be done
2760 whenever Exim's configuration file, or any file that is incorporated into it by
2761 means of the &%.include%& facility, is changed, and also whenever a new version
2762 of Exim is installed. It is not necessary to do this when other files that are
2763 referenced from the configuration (for example, alias files) are changed,
2764 because these are reread each time they are used.
2766 .vitem &%-bdf%&
2767 .oindex "&%-bdf%&"
2768 This option has the same effect as &%-bd%& except that it never disconnects
2769 from the controlling terminal, even when no debugging is specified.
2771 .vitem &%-be%&
2772 .oindex "&%-be%&"
2773 .cindex "testing" "string expansion"
2774 .cindex "expansion" "testing"
2775 Run Exim in expansion testing mode. Exim discards its root privilege, to
2776 prevent ordinary users from using this mode to read otherwise inaccessible
2777 files. If no arguments are given, Exim runs interactively, prompting for lines
2778 of data. Otherwise, it processes each argument in turn.
2780 If Exim was built with USE_READLINE=yes in &_Local/Makefile_&, it tries
2781 to load the &%libreadline%& library dynamically whenever the &%-be%& option is
2782 used without command line arguments. If successful, it uses the &[readline()]&
2783 function, which provides extensive line-editing facilities, for reading the
2784 test data. A line history is supported.
2786 Long expansion expressions can be split over several lines by using backslash
2787 continuations. As in Exim's run time configuration, white space at the start of
2788 continuation lines is ignored. Each argument or data line is passed through the
2789 string expansion mechanism, and the result is output. Variable values from the
2790 configuration file (for example, &$qualify_domain$&) are available, but no
2791 message-specific values (such as &$sender_domain$&) are set, because no message
2792 is being processed (but see &%-bem%& and &%-Mset%&).
2794 &*Note*&: If you use this mechanism to test lookups, and you change the data
2795 files or databases you are using, you must exit and restart Exim before trying
2796 the same lookup again. Otherwise, because each Exim process caches the results
2797 of lookups, you will just get the same result as before.
2799 .vitem &%-bem%&&~<&'filename'&>
2800 .oindex "&%-bem%&"
2801 .cindex "testing" "string expansion"
2802 .cindex "expansion" "testing"
2803 This option operates like &%-be%& except that it must be followed by the name
2804 of a file. For example:
2805 .code
2806 exim -bem /tmp/testmessage
2807 .endd
2808 The file is read as a message (as if receiving a locally-submitted non-SMTP
2809 message) before any of the test expansions are done. Thus, message-specific
2810 variables such as &$message_size$& and &$header_from:$& are available. However,
2811 no &'Received:'& header is added to the message. If the &%-t%& option is set,
2812 recipients are read from the headers in the normal way, and are shown in the
2813 &$recipients$& variable. Note that recipients cannot be given on the command
2814 line, because further arguments are taken as strings to expand (just like
2815 &%-be%&).
2817 .vitem &%-bF%&&~<&'filename'&>
2818 .oindex "&%-bF%&"
2819 .cindex "system filter" "testing"
2820 .cindex "testing" "system filter"
2821 This option is the same as &%-bf%& except that it assumes that the filter being
2822 tested is a system filter. The additional commands that are available only in
2823 system filters are recognized.
2825 .vitem &%-bf%&&~<&'filename'&>
2826 .oindex "&%-bf%&"
2827 .cindex "filter" "testing"
2828 .cindex "testing" "filter file"
2829 .cindex "forward file" "testing"
2830 .cindex "testing" "forward file"
2831 .cindex "Sieve filter" "testing"
2832 This option runs Exim in user filter testing mode; the file is the filter file
2833 to be tested, and a test message must be supplied on the standard input. If
2834 there are no message-dependent tests in the filter, an empty file can be
2835 supplied.
2837 If you want to test a system filter file, use &%-bF%& instead of &%-bf%&. You
2838 can use both &%-bF%& and &%-bf%& on the same command, in order to test a system
2839 filter and a user filter in the same run. For example:
2840 .code
2841 exim -bF /system/filter -bf /user/filter </test/message
2842 .endd
2843 This is helpful when the system filter adds header lines or sets filter
2844 variables that are used by the user filter.
2846 If the test filter file does not begin with one of the special lines
2847 .code
2848 # Exim filter
2849 # Sieve filter
2850 .endd
2851 it is taken to be a normal &_.forward_& file, and is tested for validity under
2852 that interpretation. See sections &<<SECTitenonfilred>>& to
2853 &<<SECTspecitredli>>& for a description of the possible contents of non-filter
2854 redirection lists.
2856 The result of an Exim command that uses &%-bf%&, provided no errors are
2857 detected, is a list of the actions that Exim would try to take if presented
2858 with the message for real. More details of filter testing are given in the
2859 separate document entitled &'Exim's interfaces to mail filtering'&.
2861 When testing a filter file,
2862 .cindex "&""From""& line"
2863 .cindex "envelope sender"
2864 .oindex "&%-f%&" "for filter testing"
2865 the envelope sender can be set by the &%-f%& option,
2866 or by a &"From&~"& line at the start of the test message. Various parameters
2867 that would normally be taken from the envelope recipient address of the message
2868 can be set by means of additional command line options (see the next four
2869 options).
2871 .vitem &%-bfd%&&~<&'domain'&>
2872 .oindex "&%-bfd%&"
2873 .vindex "&$qualify_domain$&"
2874 This sets the domain of the recipient address when a filter file is being
2875 tested by means of the &%-bf%& option. The default is the value of
2876 &$qualify_domain$&.
2878 .vitem &%-bfl%&&~<&'local&~part'&>
2879 .oindex "&%-bfl%&"
2880 This sets the local part of the recipient address when a filter file is being
2881 tested by means of the &%-bf%& option. The default is the username of the
2882 process that calls Exim. A local part should be specified with any prefix or
2883 suffix stripped, because that is how it appears to the filter when a message is
2884 actually being delivered.
2886 .vitem &%-bfp%&&~<&'prefix'&>
2887 .oindex "&%-bfp%&"
2888 This sets the prefix of the local part of the recipient address when a filter
2889 file is being tested by means of the &%-bf%& option. The default is an empty
2890 prefix.
2892 .vitem &%-bfs%&&~<&'suffix'&>
2893 .oindex "&%-bfs%&"
2894 This sets the suffix of the local part of the recipient address when a filter
2895 file is being tested by means of the &%-bf%& option. The default is an empty
2896 suffix.
2898 .vitem &%-bh%&&~<&'IP&~address'&>
2899 .oindex "&%-bh%&"
2900 .cindex "testing" "incoming SMTP"
2901 .cindex "SMTP" "testing incoming"
2902 .cindex "testing" "relay control"
2903 .cindex "relaying" "testing configuration"
2904 .cindex "policy control" "testing"
2905 .cindex "debugging" "&%-bh%& option"
2906 This option runs a fake SMTP session as if from the given IP address, using the
2907 standard input and output. The IP address may include a port number at the end,
2908 after a full stop. For example:
2909 .code
2910 exim -bh
2911 exim -bh fe80::a00:20ff:fe86:a061.5678
2912 .endd
2913 When an IPv6 address is given, it is converted into canonical form. In the case
2914 of the second example above, the value of &$sender_host_address$& after
2915 conversion to the canonical form is
2916 &`fe80:0000:0000:0a00:20ff:fe86:a061.5678`&.
2918 Comments as to what is going on are written to the standard error file. These
2919 include lines beginning with &"LOG"& for anything that would have been logged.
2920 This facility is provided for testing configuration options for incoming
2921 messages, to make sure they implement the required policy. For example, you can
2922 test your relay controls using &%-bh%&.
2924 &*Warning 1*&:
2925 .cindex "RFC 1413"
2926 You can test features of the configuration that rely on ident (RFC 1413)
2927 information by using the &%-oMt%& option. However, Exim cannot actually perform
2928 an ident callout when testing using &%-bh%& because there is no incoming SMTP
2929 connection.
2931 &*Warning 2*&: Address verification callouts (see section &<<SECTcallver>>&)
2932 are also skipped when testing using &%-bh%&. If you want these callouts to
2933 occur, use &%-bhc%& instead.
2935 Messages supplied during the testing session are discarded, and nothing is
2936 written to any of the real log files. There may be pauses when DNS (and other)
2937 lookups are taking place, and of course these may time out. The &%-oMi%& option
2938 can be used to specify a specific IP interface and port if this is important,
2939 and &%-oMaa%& and &%-oMai%& can be used to set parameters as if the SMTP
2940 session were authenticated.
2942 The &'exim_checkaccess'& utility is a &"packaged"& version of &%-bh%& whose
2943 output just states whether a given recipient address from a given host is
2944 acceptable or not. See section &<<SECTcheckaccess>>&.
2946 Features such as authentication and encryption, where the client input is not
2947 plain text, cannot easily be tested with &%-bh%&. Instead, you should use a
2948 specialized SMTP test program such as
2949 &url(http://jetmore.org/john/code/#swaks,swaks).
2951 .vitem &%-bhc%&&~<&'IP&~address'&>
2952 .oindex "&%-bhc%&"
2953 This option operates in the same way as &%-bh%&, except that address
2954 verification callouts are performed if required. This includes consulting and
2955 updating the callout cache database.
2957 .vitem &%-bi%&
2958 .oindex "&%-bi%&"
2959 .cindex "alias file" "building"
2960 .cindex "building alias file"
2961 .cindex "Sendmail compatibility" "&%-bi%& option"
2962 Sendmail interprets the &%-bi%& option as a request to rebuild its alias file.
2963 Exim does not have the concept of a single alias file, and so it cannot mimic
2964 this behaviour. However, calls to &_/usr/lib/sendmail_& with the &%-bi%& option
2965 tend to appear in various scripts such as NIS make files, so the option must be
2966 recognized.
2968 If &%-bi%& is encountered, the command specified by the &%bi_command%&
2969 configuration option is run, under the uid and gid of the caller of Exim. If
2970 the &%-oA%& option is used, its value is passed to the command as an argument.
2971 The command set by &%bi_command%& may not contain arguments. The command can
2972 use the &'exim_dbmbuild'& utility, or some other means, to rebuild alias files
2973 if this is required. If the &%bi_command%& option is not set, calling Exim with
2974 &%-bi%& is a no-op.
2976 .new
2977 . // Keep :help first, then the rest in alphabetical order
2978 .vitem &%-bI:help%&
2979 .oindex "&%-bI:help%&"
2980 .cindex "querying exim information"
2981 We shall provide various options starting &`-bI:`& for querying Exim for
2982 information. The output of many of these will be intended for machine
2983 consumption. This one is not. The &%-bI:help%& option asks Exim for a
2984 synopsis of supported options beginning &`-bI:`&. Use of any of these
2985 options shall cause Exim to exit after producing the requested output.
2987 .vitem &%-bI:dscp%&
2988 .oindex "&%-bI:dscp%&"
2989 .cindex "DSCP" "values"
2990 This option causes Exim to emit an alphabetically sorted list of all
2991 recognised DSCP names.
2993 .vitem &%-bI:sieve%&
2994 .oindex "&%-bI:sieve%&"
2995 .cindex "Sieve filter" "capabilities"
2996 This option causes Exim to emit an alphabetically sorted list of all supported
2997 Sieve protocol extensions on stdout, one per line. This is anticipated to be
2998 useful for ManageSieve (RFC 5804) implementations, in providing that protocol's
2999 &`SIEVE`& capability response line. As the precise list may depend upon
3000 compile-time build options, which this option will adapt to, this is the only
3001 way to guarantee a correct response.
3002 .wen
3004 .vitem &%-bm%&
3005 .oindex "&%-bm%&"
3006 .cindex "local message reception"
3007 This option runs an Exim receiving process that accepts an incoming,
3008 locally-generated message on the standard input. The recipients are given as the
3009 command arguments (except when &%-t%& is also present &-- see below). Each
3010 argument can be a comma-separated list of RFC 2822 addresses. This is the
3011 default option for selecting the overall action of an Exim call; it is assumed
3012 if no other conflicting option is present.
3014 If any addresses in the message are unqualified (have no domain), they are
3015 qualified by the values of the &%qualify_domain%& or &%qualify_recipient%&
3016 options, as appropriate. The &%-bnq%& option (see below) provides a way of
3017 suppressing this for special cases.
3019 Policy checks on the contents of local messages can be enforced by means of
3020 the non-SMTP ACL. See chapter &<<CHAPACL>>& for details.
3022 .cindex "return code" "for &%-bm%&"
3023 The return code is zero if the message is successfully accepted. Otherwise, the
3024 action is controlled by the &%-oe%&&'x'& option setting &-- see below.
3026 The format
3027 .cindex "message" "format"
3028 .cindex "format" "message"
3029 .cindex "&""From""& line"
3030 .cindex "UUCP" "&""From""& line"
3031 .cindex "Sendmail compatibility" "&""From""& line"
3032 of the message must be as defined in RFC 2822, except that, for
3033 compatibility with Sendmail and Smail, a line in one of the forms
3034 .code
3035 From sender Fri Jan 5 12:55 GMT 1997
3036 From sender Fri, 5 Jan 97 12:55:01
3037 .endd
3038 (with the weekday optional, and possibly with additional text after the date)
3039 is permitted to appear at the start of the message. There appears to be no
3040 authoritative specification of the format of this line. Exim recognizes it by
3041 matching against the regular expression defined by the &%uucp_from_pattern%&
3042 option, which can be changed if necessary.
3044 .oindex "&%-f%&" "overriding &""From""& line"
3045 The specified sender is treated as if it were given as the argument to the
3046 &%-f%& option, but if a &%-f%& option is also present, its argument is used in
3047 preference to the address taken from the message. The caller of Exim must be a
3048 trusted user for the sender of a message to be set in this way.
3050 .vitem &%-bmalware%&&~<&'filename'&>
3051 .oindex "&%-bmalware%&"
3052 .cindex "testing", "malware"
3053 .cindex "malware scan test"
3054 This debugging option causes Exim to scan the given file,
3055 using the malware scanning framework. The option of &%av_scanner%& influences
3056 this option, so if &%av_scanner%&'s value is dependent upon an expansion then
3057 the expansion should have defaults which apply to this invocation. ACLs are
3058 not invoked, so if &%av_scanner%& references an ACL variable then that variable
3059 will never be populated and &%-bmalware%& will fail.
3061 Exim will have changed working directory before resolving the filename, so
3062 using fully qualified pathnames is advisable. Exim will be running as the Exim
3063 user when it tries to open the file, rather than as the invoking user.
3064 This option requires admin privileges.
3066 The &%-bmalware%& option will not be extended to be more generally useful,
3067 there are better tools for file-scanning. This option exists to help
3068 administrators verify their Exim and AV scanner configuration.
3070 .vitem &%-bnq%&
3071 .oindex "&%-bnq%&"
3072 .cindex "address qualification, suppressing"
3073 By default, Exim automatically qualifies unqualified addresses (those
3074 without domains) that appear in messages that are submitted locally (that
3075 is, not over TCP/IP). This qualification applies both to addresses in
3076 envelopes, and addresses in header lines. Sender addresses are qualified using
3077 &%qualify_domain%&, and recipient addresses using &%qualify_recipient%& (which
3078 defaults to the value of &%qualify_domain%&).
3080 Sometimes, qualification is not wanted. For example, if &%-bS%& (batch SMTP) is
3081 being used to re-submit messages that originally came from remote hosts after
3082 content scanning, you probably do not want to qualify unqualified addresses in
3083 header lines. (Such lines will be present only if you have not enabled a header
3084 syntax check in the appropriate ACL.)
3086 The &%-bnq%& option suppresses all qualification of unqualified addresses in
3087 messages that originate on the local host. When this is used, unqualified
3088 addresses in the envelope provoke errors (causing message rejection) and
3089 unqualified addresses in header lines are left alone.
3092 .vitem &%-bP%&
3093 .oindex "&%-bP%&"
3094 .cindex "configuration options" "extracting"
3095 .cindex "options" "configuration &-- extracting"
3096 If this option is given with no arguments, it causes the values of all Exim's
3097 main configuration options to be written to the standard output. The values
3098 of one or more specific options can be requested by giving their names as
3099 arguments, for example:
3100 .code
3101 exim -bP qualify_domain hold_domains
3102 .endd
3103 .cindex "hiding configuration option values"
3104 .cindex "configuration options" "hiding value of"
3105 .cindex "options" "hiding value of"
3106 However, any option setting that is preceded by the word &"hide"& in the
3107 configuration file is not shown in full, except to an admin user. For other
3108 users, the output is as in this example:
3109 .code
3110 mysql_servers = <value not displayable>
3111 .endd
3112 If &%configure_file%& is given as an argument, the name of the run time
3113 configuration file is output.
3114 If a list of configuration files was supplied, the value that is output here
3115 is the name of the file that was actually used.
3117 .new
3118 .cindex "options" "hiding name of"
3119 If the &%-n%& flag is given, then for most modes of &%-bP%& operation the
3120 name will not be output.
3121 .wen
3123 .cindex "daemon" "process id (pid)"
3124 .cindex "pid (process id)" "of daemon"
3125 If &%log_file_path%& or &%pid_file_path%& are given, the names of the
3126 directories where log files and daemon pid files are written are output,
3127 respectively. If these values are unset, log files are written in a
3128 sub-directory of the spool directory called &%log%&, and the pid file is
3129 written directly into the spool directory.
3131 If &%-bP%& is followed by a name preceded by &`+`&, for example,
3132 .code
3133 exim -bP +local_domains
3134 .endd
3135 it searches for a matching named list of any type (domain, host, address, or
3136 local part) and outputs what it finds.
3138 .cindex "options" "router &-- extracting"
3139 .cindex "options" "transport &-- extracting"
3140 .cindex "options" "authenticator &-- extracting"
3141 If one of the words &%router%&, &%transport%&, or &%authenticator%& is given,
3142 followed by the name of an appropriate driver instance, the option settings for
3143 that driver are output. For example:
3144 .code
3145 exim -bP transport local_delivery
3146 .endd
3147 The generic driver options are output first, followed by the driver's private
3148 options. A list of the names of drivers of a particular type can be obtained by
3149 using one of the words &%router_list%&, &%transport_list%&, or
3150 &%authenticator_list%&, and a complete list of all drivers with their option
3151 settings can be obtained by using &%routers%&, &%transports%&, or
3152 &%authenticators%&.
3154 .cindex "options" "macro &-- extracting"
3155 If invoked by an admin user, then &%macro%&, &%macro_list%& and &%macros%&
3156 are available, similarly to the drivers. Because macros are sometimes used
3157 for storing passwords, this option is restricted.
3158 The output format is one item per line.
3160 .vitem &%-bp%&
3161 .oindex "&%-bp%&"
3162 .cindex "queue" "listing messages on"
3163 .cindex "listing" "messages on the queue"
3164 This option requests a listing of the contents of the mail queue on the
3165 standard output. If the &%-bp%& option is followed by a list of message ids,
3166 just those messages are listed. By default, this option can be used only by an
3167 admin user. However, the &%queue_list_requires_admin%& option can be set false
3168 to allow any user to see the queue.
3170 Each message on the queue is displayed as in the following example:
3171 .code
3172 25m 2.9K 0t5C6f-0000c8-00 <alice@wonderland.fict.example>
3173 red.king@looking-glass.fict.example
3174 <other addresses>
3175 .endd
3176 .cindex "message" "size in queue listing"
3177 .cindex "size" "of message"
3178 The first line contains the length of time the message has been on the queue
3179 (in this case 25 minutes), the size of the message (2.9K), the unique local
3180 identifier for the message, and the message sender, as contained in the
3181 envelope. For bounce messages, the sender address is empty, and appears as
3182 &"<>"&. If the message was submitted locally by an untrusted user who overrode
3183 the default sender address, the user's login name is shown in parentheses
3184 before the sender address.
3186 .cindex "frozen messages" "in queue listing"
3187 If the message is frozen (attempts to deliver it are suspended) then the text
3188 &"*** frozen ***"& is displayed at the end of this line.
3190 The recipients of the message (taken from the envelope, not the headers) are
3191 displayed on subsequent lines. Those addresses to which the message has already
3192 been delivered are marked with the letter D. If an original address gets
3193 expanded into several addresses via an alias or forward file, the original is
3194 displayed with a D only when deliveries for all of its child addresses are
3195 complete.
3198 .vitem &%-bpa%&
3199 .oindex "&%-bpa%&"
3200 This option operates like &%-bp%&, but in addition it shows delivered addresses
3201 that were generated from the original top level address(es) in each message by
3202 alias or forwarding operations. These addresses are flagged with &"+D"& instead
3203 of just &"D"&.
3206 .vitem &%-bpc%&
3207 .oindex "&%-bpc%&"
3208 .cindex "queue" "count of messages on"
3209 This option counts the number of messages on the queue, and writes the total
3210 to the standard output. It is restricted to admin users, unless
3211 &%queue_list_requires_admin%& is set false.
3214 .vitem &%-bpr%&
3215 .oindex "&%-bpr%&"
3216 This option operates like &%-bp%&, but the output is not sorted into
3217 chronological order of message arrival. This can speed it up when there are
3218 lots of messages on the queue, and is particularly useful if the output is
3219 going to be post-processed in a way that doesn't need the sorting.
3221 .vitem &%-bpra%&
3222 .oindex "&%-bpra%&"
3223 This option is a combination of &%-bpr%& and &%-bpa%&.
3225 .vitem &%-bpru%&
3226 .oindex "&%-bpru%&"
3227 This option is a combination of &%-bpr%& and &%-bpu%&.
3230 .vitem &%-bpu%&
3231 .oindex "&%-bpu%&"
3232 This option operates like &%-bp%& but shows only undelivered top-level
3233 addresses for each message displayed. Addresses generated by aliasing or
3234 forwarding are not shown, unless the message was deferred after processing by a
3235 router with the &%one_time%& option set.
3238 .vitem &%-brt%&
3239 .oindex "&%-brt%&"
3240 .cindex "testing" "retry configuration"
3241 .cindex "retry" "configuration testing"
3242 This option is for testing retry rules, and it must be followed by up to three
3243 arguments. It causes Exim to look for a retry rule that matches the values
3244 and to write it to the standard output. For example:
3245 .code
3246 exim -brt bach.comp.mus.example
3247 Retry rule: *.comp.mus.example F,2h,15m; F,4d,30m;
3248 .endd
3249 See chapter &<<CHAPretry>>& for a description of Exim's retry rules. The first
3250 argument, which is required, can be a complete address in the form
3251 &'local_part@domain'&, or it can be just a domain name. If the second argument
3252 contains a dot, it is interpreted as an optional second domain name; if no
3253 retry rule is found for the first argument, the second is tried. This ties in
3254 with Exim's behaviour when looking for retry rules for remote hosts &-- if no
3255 rule is found that matches the host, one that matches the mail domain is
3256 sought. Finally, an argument that is the name of a specific delivery error, as
3257 used in setting up retry rules, can be given. For example:
3258 .code
3259 exim -brt haydn.comp.mus.example quota_3d
3260 Retry rule: *@haydn.comp.mus.example quota_3d F,1h,15m
3261 .endd
3263 .vitem &%-brw%&
3264 .oindex "&%-brw%&"
3265 .cindex "testing" "rewriting"
3266 .cindex "rewriting" "testing"
3267 This option is for testing address rewriting rules, and it must be followed by
3268 a single argument, consisting of either a local part without a domain, or a
3269 complete address with a fully qualified domain. Exim outputs how this address
3270 would be rewritten for each possible place it might appear. See chapter
3271 &<<CHAPrewrite>>& for further details.
3273 .vitem &%-bS%&
3274 .oindex "&%-bS%&"
3275 .cindex "SMTP" "batched incoming"
3276 .cindex "batched SMTP input"
3277 This option is used for batched SMTP input, which is an alternative interface
3278 for non-interactive local message submission. A number of messages can be
3279 submitted in a single run. However, despite its name, this is not really SMTP
3280 input. Exim reads each message's envelope from SMTP commands on the standard
3281 input, but generates no responses. If the caller is trusted, or
3282 &%untrusted_set_sender%& is set, the senders in the SMTP MAIL commands are
3283 believed; otherwise the sender is always the caller of Exim.
3285 The message itself is read from the standard input, in SMTP format (leading
3286 dots doubled), terminated by a line containing just a single dot. An error is
3287 provoked if the terminating dot is missing. A further message may then follow.
3289 As for other local message submissions, the contents of incoming batch SMTP
3290 messages can be checked using the non-SMTP ACL (see chapter &<<CHAPACL>>&).
3291 Unqualified addresses are automatically qualified using &%qualify_domain%& and
3292 &%qualify_recipient%&, as appropriate, unless the &%-bnq%& option is used.
3294 Some other SMTP commands are recognized in the input. HELO and EHLO act
3295 as RSET; VRFY, EXPN, ETRN, and HELP act as NOOP;
3296 QUIT quits, ignoring the rest of the standard input.
3298 .cindex "return code" "for &%-bS%&"
3299 If any error is encountered, reports are written to the standard output and
3300 error streams, and Exim gives up immediately. The return code is 0 if no error
3301 was detected; it is 1 if one or more messages were accepted before the error
3302 was detected; otherwise it is 2.
3304 More details of input using batched SMTP are given in section
3305 &<<SECTincomingbatchedSMTP>>&.
3307 .vitem &%-bs%&
3308 .oindex "&%-bs%&"
3309 .cindex "SMTP" "local input"
3310 .cindex "local SMTP input"
3311 This option causes Exim to accept one or more messages by reading SMTP commands
3312 on the standard input, and producing SMTP replies on the standard output. SMTP
3313 policy controls, as defined in ACLs (see chapter &<<CHAPACL>>&) are applied.
3314 Some user agents use this interface as a way of passing locally-generated
3315 messages to the MTA.
3317 In
3318 .cindex "sender" "source of"
3319 this usage, if the caller of Exim is trusted, or &%untrusted_set_sender%& is
3320 set, the senders of messages are taken from the SMTP MAIL commands.
3321 Otherwise the content of these commands is ignored and the sender is set up as
3322 the calling user. Unqualified addresses are automatically qualified using
3323 &%qualify_domain%& and &%qualify_recipient%&, as appropriate, unless the
3324 &%-bnq%& option is used.
3326 .cindex "inetd"
3327 The
3328 &%-bs%& option is also used to run Exim from &'inetd'&, as an alternative to
3329 using a listening daemon. Exim can distinguish the two cases by checking
3330 whether the standard input is a TCP/IP socket. When Exim is called from
3331 &'inetd'&, the source of the mail is assumed to be remote, and the comments
3332 above concerning senders and qualification do not apply. In this situation,
3333 Exim behaves in exactly the same way as it does when receiving a message via
3334 the listening daemon.
3336 .vitem &%-bt%&
3337 .oindex "&%-bt%&"
3338 .cindex "testing" "addresses"
3339 .cindex "address" "testing"
3340 This option runs Exim in address testing mode, in which each argument is taken
3341 as a recipient address to be tested for deliverability. The results are
3342 written to the standard output. If a test fails, and the caller is not an admin
3343 user, no details of the failure are output, because these might contain
3344 sensitive information such as usernames and passwords for database lookups.
3346 If no arguments are given, Exim runs in an interactive manner, prompting with a
3347 right angle bracket for addresses to be tested.
3349 Unlike the &%-be%& test option, you cannot arrange for Exim to use the
3350 &[readline()]& function, because it is running as &'root'& and there are
3351 security issues.
3353 Each address is handled as if it were the recipient address of a message
3354 (compare the &%-bv%& option). It is passed to the routers and the result is
3355 written to the standard output. However, any router that has
3356 &%no_address_test%& set is bypassed. This can make &%-bt%& easier to use for
3357 genuine routing tests if your first router passes everything to a scanner
3358 program.
3360 .cindex "return code" "for &%-bt%&"
3361 The return code is 2 if any address failed outright; it is 1 if no address
3362 failed outright but at least one could not be resolved for some reason. Return
3363 code 0 is given only when all addresses succeed.
3365 .cindex "duplicate addresses"
3366 &*Note*&: When actually delivering a message, Exim removes duplicate recipient
3367 addresses after routing is complete, so that only one delivery takes place.
3368 This does not happen when testing with &%-bt%&; the full results of routing are
3369 always shown.
3371 &*Warning*&: &%-bt%& can only do relatively simple testing. If any of the
3372 routers in the configuration makes any tests on the sender address of a
3373 message,
3374 .oindex "&%-f%&" "for address testing"
3375 you can use the &%-f%& option to set an appropriate sender when running
3376 &%-bt%& tests. Without it, the sender is assumed to be the calling user at the
3377 default qualifying domain. However, if you have set up (for example) routers
3378 whose behaviour depends on the contents of an incoming message, you cannot test
3379 those conditions using &%-bt%&. The &%-N%& option provides a possible way of
3380 doing such tests.
3382 .vitem &%-bV%&
3383 .oindex "&%-bV%&"
3384 .cindex "version number of Exim"
3385 This option causes Exim to write the current version number, compilation
3386 number, and compilation date of the &'exim'& binary to the standard output.
3387 It also lists the DBM library that is being used, the optional modules (such as
3388 specific lookup types), the drivers that are included in the binary, and the
3389 name of the run time configuration file that is in use.
3391 As part of its operation, &%-bV%& causes Exim to read and syntax check its
3392 configuration file. However, this is a static check only. It cannot check
3393 values that are to be expanded. For example, although a misspelt ACL verb is
3394 detected, an error in the verb's arguments is not. You cannot rely on &%-bV%&
3395 alone to discover (for example) all the typos in the configuration; some
3396 realistic testing is needed. The &%-bh%& and &%-N%& options provide more
3397 dynamic testing facilities.
3399 .vitem &%-bv%&
3400 .oindex "&%-bv%&"
3401 .cindex "verifying address" "using &%-bv%&"
3402 .cindex "address" "verification"
3403 This option runs Exim in address verification mode, in which each argument is
3404 taken as a recipient address to be verified by the routers. (This does
3405 not involve any verification callouts). During normal operation, verification
3406 happens mostly as a consequence processing a &%verify%& condition in an ACL
3407 (see chapter &<<CHAPACL>>&). If you want to test an entire ACL, possibly
3408 including callouts, see the &%-bh%& and &%-bhc%& options.
3410 If verification fails, and the caller is not an admin user, no details of the
3411 failure are output, because these might contain sensitive information such as
3412 usernames and passwords for database lookups.
3414 If no arguments are given, Exim runs in an interactive manner, prompting with a
3415 right angle bracket for addresses to be verified.
3417 Unlike the &%-be%& test option, you cannot arrange for Exim to use the
3418 &[readline()]& function, because it is running as &'exim'& and there are
3419 security issues.
3421 Verification differs from address testing (the &%-bt%& option) in that routers
3422 that have &%no_verify%& set are skipped, and if the address is accepted by a
3423 router that has &%fail_verify%& set, verification fails. The address is
3424 verified as a recipient if &%-bv%& is used; to test verification for a sender
3425 address, &%-bvs%& should be used.
3427 If the &%-v%& option is not set, the output consists of a single line for each
3428 address, stating whether it was verified or not, and giving a reason in the
3429 latter case. Without &%-v%&, generating more than one address by redirection
3430 causes verification to end successfully, without considering the generated
3431 addresses. However, if just one address is generated, processing continues,
3432 and the generated address must verify successfully for the overall verification
3433 to succeed.
3435 When &%-v%& is set, more details are given of how the address has been handled,
3436 and in the case of address redirection, all the generated addresses are also
3437 considered. Verification may succeed for some and fail for others.
3439 The
3440 .cindex "return code" "for &%-bv%&"
3441 return code is 2 if any address failed outright; it is 1 if no address
3442 failed outright but at least one could not be resolved for some reason. Return
3443 code 0 is given only when all addresses succeed.
3445 If any of the routers in the configuration makes any tests on the sender
3446 address of a message, you should use the &%-f%& option to set an appropriate
3447 sender when running &%-bv%& tests. Without it, the sender is assumed to be the
3448 calling user at the default qualifying domain.
3450 .vitem &%-bvs%&
3451 .oindex "&%-bvs%&"
3452 This option acts like &%-bv%&, but verifies the address as a sender rather
3453 than a recipient address. This affects any rewriting and qualification that
3454 might happen.
3456 .vitem &%-bw%&
3457 .oindex "&%-bw%&"
3458 .cindex "daemon"
3459 .cindex "inetd"
3460 .cindex "inetd" "wait mode"
3461 This option runs Exim as a daemon, awaiting incoming SMTP connections,
3462 similarly to the &%-bd%& option. All port specifications on the command-line
3463 and in the configuration file are ignored. Queue-running may not be specified.
3465 In this mode, Exim expects to be passed a socket as fd 0 (stdin) which is
3466 listening for connections. This permits the system to start up and have
3467 inetd (or equivalent) listen on the SMTP ports, starting an Exim daemon for
3468 each port only when the first connection is received.
3470 If the option is given as &%-bw%&<&'time'&> then the time is a timeout, after
3471 which the daemon will exit, which should cause inetd to listen once more.
3473 .vitem &%-C%&&~<&'filelist'&>
3474 .oindex "&%-C%&"
3475 .cindex "configuration file" "alternate"
3476 .cindex "CONFIGURE_FILE"
3477 .cindex "alternate configuration file"
3478 This option causes Exim to find the run time configuration file from the given
3479 list instead of from the list specified by the CONFIGURE_FILE
3480 compile-time setting. Usually, the list will consist of just a single file
3481 name, but it can be a colon-separated list of names. In this case, the first
3482 file that exists is used. Failure to open an existing file stops Exim from
3483 proceeding any further along the list, and an error is generated.
3485 When this option is used by a caller other than root, and the list is different
3486 from the compiled-in list, Exim gives up its root privilege immediately, and
3487 runs with the real and effective uid and gid set to those of the caller.
3488 However, if a TRUSTED_CONFIG_LIST file is defined in &_Local/Makefile_&, that
3489 file contains a list of full pathnames, one per line, for configuration files
3490 which are trusted. Root privilege is retained for any configuration file so
3491 listed, as long as the caller is the Exim user (or the user specified in the
3492 CONFIGURE_OWNER option, if any), and as long as the configuration file is
3493 not writeable by inappropriate users or groups.
3495 Leaving TRUSTED_CONFIG_LIST unset precludes the possibility of testing a
3496 configuration using &%-C%& right through message reception and delivery,
3497 even if the caller is root. The reception works, but by that time, Exim is
3498 running as the Exim user, so when it re-executes to regain privilege for the
3499 delivery, the use of &%-C%& causes privilege to be lost. However, root can
3500 test reception and delivery using two separate commands (one to put a message
3501 on the queue, using &%-odq%&, and another to do the delivery, using &%-M%&).
3503 If ALT_CONFIG_PREFIX is defined &_in Local/Makefile_&, it specifies a
3504 prefix string with which any file named in a &%-C%& command line option
3505 must start. In addition, the file name must not contain the sequence &`/../`&.
3506 However, if the value of the &%-C%& option is identical to the value of
3507 CONFIGURE_FILE in &_Local/Makefile_&, Exim ignores &%-C%& and proceeds as
3508 usual. There is no default setting for ALT_CONFIG_PREFIX; when it is
3509 unset, any file name can be used with &%-C%&.
3511 ALT_CONFIG_PREFIX can be used to confine alternative configuration files
3512 to a directory to which only root has access. This prevents someone who has
3513 broken into the Exim account from running a privileged Exim with an arbitrary
3514 configuration file.
3516 The &%-C%& facility is useful for ensuring that configuration files are
3517 syntactically correct, but cannot be used for test deliveries, unless the
3518 caller is privileged, or unless it is an exotic configuration that does not
3519 require privilege. No check is made on the owner or group of the files
3520 specified by this option.
3523 .vitem &%-D%&<&'macro'&>=<&'value'&>
3524 .oindex "&%-D%&"
3525 .cindex "macro" "setting on command line"
3526 This option can be used to override macro definitions in the configuration file
3527 (see section &<<SECTmacrodefs>>&). However, like &%-C%&, if it is used by an
3528 unprivileged caller, it causes Exim to give up its root privilege.
3529 If DISABLE_D_OPTION is defined in &_Local/Makefile_&, the use of &%-D%& is
3530 completely disabled, and its use causes an immediate error exit.
3532 If WHITELIST_D_MACROS is defined in &_Local/Makefile_& then it should be a
3533 colon-separated list of macros which are considered safe and, if &%-D%& only
3534 supplies macros from this list, and the values are acceptable, then Exim will
3535 not give up root privilege if the caller is root, the Exim run-time user, or
3536 the CONFIGURE_OWNER, if set. This is a transition mechanism and is expected
3537 to be removed in the future. Acceptable values for the macros satisfy the
3538 regexp: &`^[A-Za-z0-9_/.-]*$`&
3540 The entire option (including equals sign if present) must all be within one
3541 command line item. &%-D%& can be used to set the value of a macro to the empty
3542 string, in which case the equals sign is optional. These two commands are
3543 synonymous:
3544 .code
3545 exim -DABC ...
3546 exim -DABC= ...
3547 .endd
3548 To include spaces in a macro definition item, quotes must be used. If you use
3549 quotes, spaces are permitted around the macro name and the equals sign. For
3550 example:
3551 .code
3552 exim '-D ABC = something' ...
3553 .endd
3554 &%-D%& may be repeated up to 10 times on a command line.
3557 .vitem &%-d%&<&'debug&~options'&>
3558 .oindex "&%-d%&"
3559 .cindex "debugging" "list of selectors"
3560 .cindex "debugging" "&%-d%& option"
3561 This option causes debugging information to be written to the standard
3562 error stream. It is restricted to admin users because debugging output may show
3563 database queries that contain password information. Also, the details of users'
3564 filter files should be protected. If a non-admin user uses &%-d%&, Exim
3565 writes an error message to the standard error stream and exits with a non-zero
3566 return code.
3568 When &%-d%& is used, &%-v%& is assumed. If &%-d%& is given on its own, a lot of
3569 standard debugging data is output. This can be reduced, or increased to include
3570 some more rarely needed information, by directly following &%-d%& with a string
3571 made up of names preceded by plus or minus characters. These add or remove sets
3572 of debugging data, respectively. For example, &%-d+filter%& adds filter
3573 debugging, whereas &%-d-all+filter%& selects only filter debugging. Note that
3574 no spaces are allowed in the debug setting. The available debugging categories
3575 are:
3576 .display
3577 &`acl `& ACL interpretation
3578 &`auth `& authenticators
3579 &`deliver `& general delivery logic
3580 &`dns `& DNS lookups (see also resolver)
3581 &`dnsbl `& DNS black list (aka RBL) code
3582 &`exec `& arguments for &[execv()]& calls
3583 &`expand `& detailed debugging for string expansions
3584 &`filter `& filter handling
3585 &`hints_lookup `& hints data lookups
3586 &`host_lookup `& all types of name-to-IP address handling
3587 &`ident `& ident lookup
3588 &`interface `& lists of local interfaces
3589 &`lists `& matching things in lists
3590 &`load `& system load checks
3591 &`local_scan `& can be used by &[local_scan()]& (see chapter &&&
3592 &<<CHAPlocalscan>>&)
3593 &`lookup `& general lookup code and all lookups
3594 &`memory `& memory handling
3595 &`pid `& add pid to debug output lines
3596 &`process_info `& setting info for the process log
3597 &`queue_run `& queue runs
3598 &`receive `& general message reception logic
3599 &`resolver `& turn on the DNS resolver's debugging output
3600 &`retry `& retry handling
3601 &`rewrite `& address rewriting
3602 &`route `& address routing
3603 &`timestamp `& add timestamp to debug output lines
3604 &`tls `& TLS logic
3605 &`transport `& transports
3606 &`uid `& changes of uid/gid and looking up uid/gid
3607 &`verify `& address verification logic
3608 &`all `& almost all of the above (see below), and also &%-v%&
3609 .endd
3610 The &`all`& option excludes &`memory`& when used as &`+all`&, but includes it
3611 for &`-all`&. The reason for this is that &`+all`& is something that people
3612 tend to use when generating debug output for Exim maintainers. If &`+memory`&
3613 is included, an awful lot of output that is very rarely of interest is
3614 generated, so it now has to be explicitly requested. However, &`-all`& does
3615 turn everything off.
3617 .cindex "resolver, debugging output"
3618 .cindex "DNS resolver, debugging output"
3619 The &`resolver`& option produces output only if the DNS resolver was compiled
3620 with DEBUG enabled. This is not the case in some operating systems. Also,
3621 unfortunately, debugging output from the DNS resolver is written to stdout
3622 rather than stderr.
3624 The default (&%-d%& with no argument) omits &`expand`&, &`filter`&,
3625 &`interface`&, &`load`&, &`memory`&, &`pid`&, &`resolver`&, and &`timestamp`&.
3626 However, the &`pid`& selector is forced when debugging is turned on for a
3627 daemon, which then passes it on to any re-executed Exims. Exim also
3628 automatically adds the pid to debug lines when several remote deliveries are
3629 run in parallel.
3631 The &`timestamp`& selector causes the current time to be inserted at the start
3632 of all debug output lines. This can be useful when trying to track down delays
3633 in processing.
3635 If the &%debug_print%& option is set in any driver, it produces output whenever
3636 any debugging is selected, or if &%-v%& is used.
3638 .vitem &%-dd%&<&'debug&~options'&>
3639 .oindex "&%-dd%&"
3640 This option behaves exactly like &%-d%& except when used on a command that
3641 starts a daemon process. In that case, debugging is turned off for the
3642 subprocesses that the daemon creates. Thus, it is useful for monitoring the
3643 behaviour of the daemon without creating as much output as full debugging does.
3645 .vitem &%-dropcr%&
3646 .oindex "&%-dropcr%&"
3647 This is an obsolete option that is now a no-op. It used to affect the way Exim
3648 handled CR and LF characters in incoming messages. What happens now is
3649 described in section &<<SECTlineendings>>&.
3651 .vitem &%-E%&
3652 .oindex "&%-E%&"
3653 .cindex "bounce message" "generating"
3654 This option specifies that an incoming message is a locally-generated delivery
3655 failure report. It is used internally by Exim when handling delivery failures
3656 and is not intended for external use. Its only effect is to stop Exim
3657 generating certain messages to the postmaster, as otherwise message cascades
3658 could occur in some situations. As part of the same option, a message id may
3659 follow the characters &%-E%&. If it does, the log entry for the receipt of the
3660 new message contains the id, following &"R="&, as a cross-reference.
3662 .vitem &%-e%&&'x'&
3663 .oindex "&%-e%&&'x'&"
3664 There are a number of Sendmail options starting with &%-oe%& which seem to be
3665 called by various programs without the leading &%o%& in the option. For
3666 example, the &%vacation%& program uses &%-eq%&. Exim treats all options of the
3667 form &%-e%&&'x'& as synonymous with the corresponding &%-oe%&&'x'& options.
3669 .vitem &%-F%&&~<&'string'&>
3670 .oindex "&%-F%&"
3671 .cindex "sender" "name"
3672 .cindex "name" "of sender"
3673 This option sets the sender's full name for use when a locally-generated
3674 message is being accepted. In the absence of this option, the user's &'gecos'&
3675 entry from the password data is used. As users are generally permitted to alter
3676 their &'gecos'& entries, no security considerations are involved. White space
3677 between &%-F%& and the <&'string'&> is optional.
3679 .vitem &%-f%&&~<&'address'&>
3680 .oindex "&%-f%&"
3681 .cindex "sender" "address"
3682 .cindex "address" "sender"
3683 .cindex "trusted users"
3684 .cindex "envelope sender"
3685 .cindex "user" "trusted"
3686 This option sets the address of the envelope sender of a locally-generated
3687 message (also known as the return path). The option can normally be used only
3688 by a trusted user, but &%untrusted_set_sender%& can be set to allow untrusted
3689 users to use it.
3691 Processes running as root or the Exim user are always trusted. Other
3692 trusted users are defined by the &%trusted_users%& or &%trusted_groups%&
3693 options. In the absence of &%-f%&, or if the caller is not trusted, the sender
3694 of a local message is set to the caller's login name at the default qualify
3695 domain.
3697 There is one exception to the restriction on the use of &%-f%&: an empty sender
3698 can be specified by any user, trusted or not, to create a message that can
3699 never provoke a bounce. An empty sender can be specified either as an empty
3700 string, or as a pair of angle brackets with nothing between them, as in these
3701 examples of shell commands:
3702 .code
3703 exim -f '<>' user@domain
3704 exim -f "" user@domain
3705 .endd
3706 In addition, the use of &%-f%& is not restricted when testing a filter file
3707 with &%-bf%& or when testing or verifying addresses using the &%-bt%& or
3708 &%-bv%& options.
3710 Allowing untrusted users to change the sender address does not of itself make
3711 it possible to send anonymous mail. Exim still checks that the &'From:'& header
3712 refers to the local user, and if it does not, it adds a &'Sender:'& header,
3713 though this can be overridden by setting &%no_local_from_check%&.
3715 White
3716 .cindex "&""From""& line"
3717 space between &%-f%& and the <&'address'&> is optional (that is, they can be
3718 given as two arguments or one combined argument). The sender of a
3719 locally-generated message can also be set (when permitted) by an initial
3720 &"From&~"& line in the message &-- see the description of &%-bm%& above &-- but
3721 if &%-f%& is also present, it overrides &"From&~"&.
3723 .vitem &%-G%&
3724 .oindex "&%-G%&"
3725 .cindex "submission fixups, suppressing (command-line)"
3726 .new
3727 This option is equivalent to an ACL applying:
3728 .code
3729 control = suppress_local_fixups
3730 .endd
3731 for every message received. Note that Sendmail will complain about such
3732 bad formatting, where Exim silently just does not fix it up. This may change
3733 in future.
3735 As this affects audit information, the caller must be a trusted user to use
3736 this option.
3737 .wen
3739 .vitem &%-h%&&~<&'number'&>
3740 .oindex "&%-h%&"
3741 .cindex "Sendmail compatibility" "&%-h%& option ignored"
3742 This option is accepted for compatibility with Sendmail, but has no effect. (In
3743 Sendmail it overrides the &"hop count"& obtained by counting &'Received:'&
3744 headers.)
3746 .vitem &%-i%&
3747 .oindex "&%-i%&"
3748 .cindex "Solaris" "&'mail'& command"
3749 .cindex "dot" "in incoming non-SMTP message"
3750 This option, which has the same effect as &%-oi%&, specifies that a dot on a
3751 line by itself should not terminate an incoming, non-SMTP message. I can find
3752 no documentation for this option in Solaris 2.4 Sendmail, but the &'mailx'&
3753 command in Solaris 2.4 uses it. See also &%-ti%&.
3755 .new
3756 .vitem &%-L%&&~<&'tag'&>
3757 .oindex "&%-L%&"
3758 .cindex "syslog" "process name; set with flag"
3759 This option is equivalent to setting &%syslog_processname%& in the config
3760 file and setting &%log_file_path%& to &`syslog`&.
3761 Its use is restricted to administrators. The configuration file has to be
3762 read and parsed, to determine access rights, before this is set and takes
3763 effect, so early configuration file errors will not honour this flag.
3765 The tag should not be longer than 32 characters.
3766 .wen
3768 .vitem &%-M%&&~<&'message&~id'&>&~<&'message&~id'&>&~...
3769 .oindex "&%-M%&"
3770 .cindex "forcing delivery"
3771 .cindex "delivery" "forcing attempt"
3772 .cindex "frozen messages" "forcing delivery"
3773 This option requests Exim to run a delivery attempt on each message in turn. If
3774 any of the messages are frozen, they are automatically thawed before the
3775 delivery attempt. The settings of &%queue_domains%&, &%queue_smtp_domains%&,
3776 and &%hold_domains%& are ignored.
3778 Retry
3779 .cindex "hints database" "overriding retry hints"
3780 hints for any of the addresses are overridden &-- Exim tries to deliver even if
3781 the normal retry time has not yet been reached. This option requires the caller
3782 to be an admin user. However, there is an option called &%prod_requires_admin%&
3783 which can be set false to relax this restriction (and also the same requirement
3784 for the &%-q%&, &%-R%&, and &%-S%& options).
3786 The deliveries happen synchronously, that is, the original Exim process does
3787 not terminate until all the delivery attempts have finished. No output is
3788 produced unless there is a serious error. If you want to see what is happening,
3789 use the &%-v%& option as well, or inspect Exim's main log.
3791 .vitem &%-Mar%&&~<&'message&~id'&>&~<&'address'&>&~<&'address'&>&~...
3792 .oindex "&%-Mar%&"
3793 .cindex "message" "adding recipients"
3794 .cindex "recipient" "adding"
3795 This option requests Exim to add the addresses to the list of recipients of the
3796 message (&"ar"& for &"add recipients"&). The first argument must be a message
3797 id, and the remaining ones must be email addresses. However, if the message is
3798 active (in the middle of a delivery attempt), it is not altered. This option
3799 can be used only by an admin user.
3801 .vitem "&%-MC%&&~<&'transport'&>&~<&'hostname'&>&~<&'sequence&~number'&>&&&
3802 &~<&'message&~id'&>"
3803 .oindex "&%-MC%&"
3804 .cindex "SMTP" "passed connection"
3805 .cindex "SMTP" "multiple deliveries"
3806 .cindex "multiple SMTP deliveries"
3807 This option is not intended for use by external callers. It is used internally
3808 by Exim to invoke another instance of itself to deliver a waiting message using
3809 an existing SMTP connection, which is passed as the standard input. Details are
3810 given in chapter &<<CHAPSMTP>>&. This must be the final option, and the caller
3811 must be root or the Exim user in order to use it.
3813 .vitem &%-MCA%&
3814 .oindex "&%-MCA%&"
3815 This option is not intended for use by external callers. It is used internally
3816 by Exim in conjunction with the &%-MC%& option. It signifies that the
3817 connection to the remote host has been authenticated.
3819 .vitem &%-MCP%&
3820 .oindex "&%-MCP%&"
3821 This option is not intended for use by external callers. It is used internally
3822 by Exim in conjunction with the &%-MC%& option. It signifies that the server to
3823 which Exim is connected supports pipelining.
3825 .vitem &%-MCQ%&&~<&'process&~id'&>&~<&'pipe&~fd'&>
3826 .oindex "&%-MCQ%&"
3827 This option is not intended for use by external callers. It is used internally
3828 by Exim in conjunction with the &%-MC%& option when the original delivery was
3829 started by a queue runner. It passes on the process id of the queue runner,
3830 together with the file descriptor number of an open pipe. Closure of the pipe
3831 signals the final completion of the sequence of processes that are passing
3832 messages through the same SMTP connection.
3834 .vitem &%-MCS%&
3835 .oindex "&%-MCS%&"
3836 This option is not intended for use by external callers. It is used internally
3837 by Exim in conjunction with the &%-MC%& option, and passes on the fact that the
3838 SMTP SIZE option should be used on messages delivered down the existing
3839 connection.
3841 .vitem &%-MCT%&
3842 .oindex "&%-MCT%&"
3843 This option is not intended for use by external callers. It is used internally
3844 by Exim in conjunction with the &%-MC%& option, and passes on the fact that the
3845 host to which Exim is connected supports TLS encryption.
3847 .vitem &%-Mc%&&~<&'message&~id'&>&~<&'message&~id'&>&~...
3848 .oindex "&%-Mc%&"
3849 .cindex "hints database" "not overridden by &%-Mc%&"
3850 .cindex "delivery" "manually started &-- not forced"
3851 This option requests Exim to run a delivery attempt on each message in turn,
3852 but unlike the &%-M%& option, it does check for retry hints, and respects any
3853 that are found. This option is not very useful to external callers. It is
3854 provided mainly for internal use by Exim when it needs to re-invoke itself in
3855 order to regain root privilege for a delivery (see chapter &<<CHAPsecurity>>&).
3856 However, &%-Mc%& can be useful when testing, in order to run a delivery that
3857 respects retry times and other options such as &%hold_domains%& that are
3858 overridden when &%-M%& is used. Such a delivery does not count as a queue run.
3859 If you want to run a specific delivery as if in a queue run, you should use
3860 &%-q%& with a message id argument. A distinction between queue run deliveries
3861 and other deliveries is made in one or two places.
3863 .vitem &%-Mes%&&~<&'message&~id'&>&~<&'address'&>
3864 .oindex "&%-Mes%&"
3865 .cindex "message" "changing sender"
3866 .cindex "sender" "changing"
3867 This option requests Exim to change the sender address in the message to the
3868 given address, which must be a fully qualified address or &"<>"& (&"es"& for
3869 &"edit sender"&). There must be exactly two arguments. The first argument must
3870 be a message id, and the second one an email address. However, if the message
3871 is active (in the middle of a delivery attempt), its status is not altered.
3872 This option can be used only by an admin user.
3874 .vitem &%-Mf%&&~<&'message&~id'&>&~<&'message&~id'&>&~...
3875 .oindex "&%-Mf%&"
3876 .cindex "freezing messages"
3877 .cindex "message" "manually freezing"
3878 This option requests Exim to mark each listed message as &"frozen"&. This
3879 prevents any delivery attempts taking place until the message is &"thawed"&,
3880 either manually or as a result of the &%auto_thaw%& configuration option.
3881 However, if any of the messages are active (in the middle of a delivery
3882 attempt), their status is not altered. This option can be used only by an admin
3883 user.
3885 .vitem &%-Mg%&&~<&'message&~id'&>&~<&'message&~id'&>&~...
3886 .oindex "&%-Mg%&"
3887 .cindex "giving up on messages"
3888 .cindex "message" "abandoning delivery attempts"
3889 .cindex "delivery" "abandoning further attempts"
3890 This option requests Exim to give up trying to deliver the listed messages,
3891 including any that are frozen. However, if any of the messages are active,
3892 their status is not altered. For non-bounce messages, a delivery error message
3893 is sent to the sender, containing the text &"cancelled by administrator"&.
3894 Bounce messages are just discarded. This option can be used only by an admin
3895 user.
3897 .vitem &%-Mmad%&&~<&'message&~id'&>&~<&'message&~id'&>&~...
3898 .oindex "&%-Mmad%&"
3899 .cindex "delivery" "cancelling all"
3900 This option requests Exim to mark all the recipient addresses in the messages
3901 as already delivered (&"mad"& for &"mark all delivered"&). However, if any
3902 message is active (in the middle of a delivery attempt), its status is not
3903 altered. This option can be used only by an admin user.
3905 .vitem &%-Mmd%&&~<&'message&~id'&>&~<&'address'&>&~<&'address'&>&~...
3906 .oindex "&%-Mmd%&"
3907 .cindex "delivery" "cancelling by address"
3908 .cindex "recipient" "removing"
3909 .cindex "removing recipients"
3910 This option requests Exim to mark the given addresses as already delivered
3911 (&"md"& for &"mark delivered"&). The first argument must be a message id, and
3912 the remaining ones must be email addresses. These are matched to recipient
3913 addresses in the message in a case-sensitive manner. If the message is active
3914 (in the middle of a delivery attempt), its status is not altered. This option
3915 can be used only by an admin user.
3917 .vitem &%-Mrm%&&~<&'message&~id'&>&~<&'message&~id'&>&~...
3918 .oindex "&%-Mrm%&"
3919 .cindex "removing messages"
3920 .cindex "abandoning mail"
3921 .cindex "message" "manually discarding"
3922 This option requests Exim to remove the given messages from the queue. No
3923 bounce messages are sent; each message is simply forgotten. However, if any of
3924 the messages are active, their status is not altered. This option can be used
3925 only by an admin user or by the user who originally caused the message to be
3926 placed on the queue.
3928 .vitem &%-Mset%&&~<&'message&~id'&>
3929 .oindex "&%-Mset%&
3930 .cindex "testing" "string expansion"
3931 .cindex "expansion" "testing"
3932 This option is useful only in conjunction with &%-be%& (that is, when testing
3933 string expansions). Exim loads the given message from its spool before doing
3934 the test expansions, thus setting message-specific variables such as
3935 &$message_size$& and the header variables. The &$recipients$& variable is made
3936 available. This feature is provided to make it easier to test expansions that
3937 make use of these variables. However, this option can be used only by an admin
3938 user. See also &%-bem%&.
3940 .vitem &%-Mt%&&~<&'message&~id'&>&~<&'message&~id'&>&~...
3941 .oindex "&%-Mt%&"
3942 .cindex "thawing messages"
3943 .cindex "unfreezing messages"
3944 .cindex "frozen messages" "thawing"
3945 .cindex "message" "thawing frozen"
3946 This option requests Exim to &"thaw"& any of the listed messages that are
3947 &"frozen"&, so that delivery attempts can resume. However, if any of the
3948 messages are active, their status is not altered. This option can be used only
3949 by an admin user.
3951 .vitem &%-Mvb%&&~<&'message&~id'&>
3952 .oindex "&%-Mvb%&"
3953 .cindex "listing" "message body"
3954 .cindex "message" "listing body of"
3955 This option causes the contents of the message body (-D) spool file to be
3956 written to the standard output. This option can be used only by an admin user.
3958 .vitem &%-Mvc%&&~<&'message&~id'&>
3959 .oindex "&%-Mvc%&"
3960 .cindex "message" "listing in RFC 2822 format"
3961 .cindex "listing" "message in RFC 2822 format"
3962 This option causes a copy of the complete message (header lines plus body) to
3963 be written to the standard output in RFC 2822 format. This option can be used
3964 only by an admin user.
3966 .vitem &%-Mvh%&&~<&'message&~id'&>
3967 .oindex "&%-Mvh%&"
3968 .cindex "listing" "message headers"
3969 .cindex "header lines" "listing"
3970 .cindex "message" "listing header lines"
3971 This option causes the contents of the message headers (-H) spool file to be
3972 written to the standard output. This option can be used only by an admin user.
3974 .vitem &%-Mvl%&&~<&'message&~id'&>
3975 .oindex "&%-Mvl%&"
3976 .cindex "listing" "message log"
3977 .cindex "message" "listing message log"
3978 This option causes the contents of the message log spool file to be written to
3979 the standard output. This option can be used only by an admin user.
3981 .vitem &%-m%&
3982 .oindex "&%-m%&"
3983 This is apparently a synonym for &%-om%& that is accepted by Sendmail, so Exim
3984 treats it that way too.
3986 .vitem &%-N%&
3987 .oindex "&%-N%&"
3988 .cindex "debugging" "&%-N%& option"
3989 .cindex "debugging" "suppressing delivery"
3990 This is a debugging option that inhibits delivery of a message at the transport
3991 level. It implies &%-v%&. Exim goes through many of the motions of delivery &--
3992 it just doesn't actually transport the message, but instead behaves as if it
3993 had successfully done so. However, it does not make any updates to the retry
3994 database, and the log entries for deliveries are flagged with &"*>"& rather
3995 than &"=>"&.
3997 Because &%-N%& discards any message to which it applies, only root or the Exim
3998 user are allowed to use it with &%-bd%&, &%-q%&, &%-R%& or &%-M%&. In other
3999 words, an ordinary user can use it only when supplying an incoming message to
4000 which it will apply. Although transportation never fails when &%-N%& is set, an
4001 address may be deferred because of a configuration problem on a transport, or a
4002 routing problem. Once &%-N%& has been used for a delivery attempt, it sticks to
4003 the message, and applies to any subsequent delivery attempts that may happen
4004 for that message.
4006 .vitem &%-n%&
4007 .oindex "&%-n%&"
4008 This option is interpreted by Sendmail to mean &"no aliasing"&.
4009 For normal modes of operation, it is ignored by Exim.
4010 When combined with &%-bP%& it suppresses the name of an option from being output.
4012 .vitem &%-O%&&~<&'data'&>
4013 .oindex "&%-O%&"
4014 This option is interpreted by Sendmail to mean &`set option`&. It is ignored by
4015 Exim.
4017 .vitem &%-oA%&&~<&'file&~name'&>
4018 .oindex "&%-oA%&"
4019 .cindex "Sendmail compatibility" "&%-oA%& option"
4020 This option is used by Sendmail in conjunction with &%-bi%& to specify an
4021 alternative alias file name. Exim handles &%-bi%& differently; see the
4022 description above.
4024 .vitem &%-oB%&&~<&'n'&>
4025 .oindex "&%-oB%&"
4026 .cindex "SMTP" "passed connection"
4027 .cindex "SMTP" "multiple deliveries"
4028 .cindex "multiple SMTP deliveries"
4029 This is a debugging option which limits the maximum number of messages that can
4030 be delivered down one SMTP connection, overriding the value set in any &(smtp)&
4031 transport. If <&'n'&> is omitted, the limit is set to 1.
4033 .vitem &%-odb%&
4034 .oindex "&%-odb%&"
4035 .cindex "background delivery"
4036 .cindex "delivery" "in the background"
4037 This option applies to all modes in which Exim accepts incoming messages,
4038 including the listening daemon. It requests &"background"& delivery of such
4039 messages, which means that the accepting process automatically starts a
4040 delivery process for each message received, but does not wait for the delivery
4041 processes to finish.
4043 When all the messages have been received, the reception process exits,
4044 leaving the delivery processes to finish in their own time. The standard output
4045 and error streams are closed at the start of each delivery process.
4046 This is the default action if none of the &%-od%& options are present.
4048 If one of the queueing options in the configuration file
4049 (&%queue_only%& or &%queue_only_file%&, for example) is in effect, &%-odb%&
4050 overrides it if &%queue_only_override%& is set true, which is the default
4051 setting. If &%queue_only_override%& is set false, &%-odb%& has no effect.
4053 .vitem &%-odf%&
4054 .oindex "&%-odf%&"
4055 .cindex "foreground delivery"
4056 .cindex "delivery" "in the foreground"
4057 This option requests &"foreground"& (synchronous) delivery when Exim has
4058 accepted a locally-generated message. (For the daemon it is exactly the same as
4059 &%-odb%&.) A delivery process is automatically started to deliver the message,
4060 and Exim waits for it to complete before proceeding.
4062 The original Exim reception process does not finish until the delivery
4063 process for the final message has ended. The standard error stream is left open
4064 during deliveries.
4066 However, like &%-odb%&, this option has no effect if &%queue_only_override%& is
4067 false and one of the queueing options in the configuration file is in effect.
4069 If there is a temporary delivery error during foreground delivery, the
4070 message is left on the queue for later delivery, and the original reception
4071 process exits. See chapter &<<CHAPnonqueueing>>& for a way of setting up a
4072 restricted configuration that never queues messages.
4075 .vitem &%-odi%&
4076 .oindex "&%-odi%&"
4077 This option is synonymous with &%-odf%&. It is provided for compatibility with
4078 Sendmail.
4080 .vitem &%-odq%&
4081 .oindex "&%-odq%&"
4082 .cindex "non-immediate delivery"
4083 .cindex "delivery" "suppressing immediate"
4084 .cindex "queueing incoming messages"
4085 This option applies to all modes in which Exim accepts incoming messages,
4086 including the listening daemon. It specifies that the accepting process should
4087 not automatically start a delivery process for each message received. Messages
4088 are placed on the queue, and remain there until a subsequent queue runner
4089 process encounters them. There are several configuration options (such as
4090 &%queue_only%&) that can be used to queue incoming messages under certain
4091 conditions. This option overrides all of them and also &%-odqs%&. It always
4092 forces queueing.
4094 .vitem &%-odqs%&
4095 .oindex "&%-odqs%&"
4096 .cindex "SMTP" "delaying delivery"
4097 This option is a hybrid between &%-odb%&/&%-odi%& and &%-odq%&.
4098 However, like &%-odb%& and &%-odi%&, this option has no effect if
4099 &%queue_only_override%& is false and one of the queueing options in the
4100 configuration file is in effect.
4102 When &%-odqs%& does operate, a delivery process is started for each incoming
4103 message, in the background by default, but in the foreground if &%-odi%& is
4104 also present. The recipient addresses are routed, and local deliveries are done
4105 in the normal way. However, if any SMTP deliveries are required, they are not
4106 done at this time, so the message remains on the queue until a subsequent queue
4107 runner process encounters it. Because routing was done, Exim knows which
4108 messages are waiting for which hosts, and so a number of messages for the same
4109 host can be sent in a single SMTP connection. The &%queue_smtp_domains%&
4110 configuration option has the same effect for specific domains. See also the
4111 &%-qq%& option.
4113 .vitem &%-oee%&
4114 .oindex "&%-oee%&"
4115 .cindex "error" "reporting"
4116 If an error is detected while a non-SMTP message is being received (for
4117 example, a malformed address), the error is reported to the sender in a mail
4118 message.
4120 .cindex "return code" "for &%-oee%&"
4121 Provided
4122 this error message is successfully sent, the Exim receiving process
4123 exits with a return code of zero. If not, the return code is 2 if the problem
4124 is that the original message has no recipients, or 1 for any other error.
4125 This is the default &%-oe%&&'x'& option if Exim is called as &'rmail'&.
4127 .vitem &%-oem%&
4128 .oindex "&%-oem%&"
4129 .cindex "error" "reporting"
4130 .cindex "return code" "for &%-oem%&"
4131 This is the same as &%-oee%&, except that Exim always exits with a non-zero
4132 return code, whether or not the error message was successfully sent.
4133 This is the default &%-oe%&&'x'& option, unless Exim is called as &'rmail'&.
4135 .vitem &%-oep%&
4136 .oindex "&%-oep%&"
4137 .cindex "error" "reporting"
4138 If an error is detected while a non-SMTP message is being received, the
4139 error is reported by writing a message to the standard error file (stderr).
4140 .cindex "return code" "for &%-oep%&"
4141 The return code is 1 for all errors.
4143 .vitem &%-oeq%&
4144 .oindex "&%-oeq%&"
4145 .cindex "error" "reporting"
4146 This option is supported for compatibility with Sendmail, but has the same
4147 effect as &%-oep%&.
4149 .vitem &%-oew%&
4150 .oindex "&%-oew%&"
4151 .cindex "error" "reporting"
4152 This option is supported for compatibility with Sendmail, but has the same
4153 effect as &%-oem%&.
4155 .vitem &%-oi%&
4156 .oindex "&%-oi%&"
4157 .cindex "dot" "in incoming non-SMTP message"
4158 This option, which has the same effect as &%-i%&, specifies that a dot on a
4159 line by itself should not terminate an incoming, non-SMTP message. Otherwise, a
4160 single dot does terminate, though Exim does no special processing for other
4161 lines that start with a dot. This option is set by default if Exim is called as
4162 &'rmail'&. See also &%-ti%&.
4164 .vitem &%-oitrue%&
4165 .oindex "&%-oitrue%&"
4166 This option is treated as synonymous with &%-oi%&.
4168 .vitem &%-oMa%&&~<&'host&~address'&>
4169 .oindex "&%-oMa%&"
4170 .cindex "sender" "host address, specifying for local message"
4171 A number of options starting with &%-oM%& can be used to set values associated
4172 with remote hosts on locally-submitted messages (that is, messages not received
4173 over TCP/IP). These options can be used by any caller in conjunction with the
4174 &%-bh%&, &%-be%&, &%-bf%&, &%-bF%&, &%-bt%&, or &%-bv%& testing options. In
4175 other circumstances, they are ignored unless the caller is trusted.
4177 The &%-oMa%& option sets the sender host address. This may include a port
4178 number at the end, after a full stop (period). For example:
4179 .code
4180 exim -bs -oMa
4181 .endd
4182 An alternative syntax is to enclose the IP address in square brackets,
4183 followed by a colon and the port number:
4184 .code
4185 exim -bs -oMa []:1234
4186 .endd
4187 The IP address is placed in the &$sender_host_address$& variable, and the
4188 port, if present, in &$sender_host_port$&. If both &%-oMa%& and &%-bh%&
4189 are present on the command line, the sender host IP address is taken from
4190 whichever one is last.
4192 .vitem &%-oMaa%&&~<&'name'&>
4193 .oindex "&%-oMaa%&"
4194 .cindex "authentication" "name, specifying for local message"
4195 See &%-oMa%& above for general remarks about the &%-oM%& options. The &%-oMaa%&
4196 option sets the value of &$sender_host_authenticated$& (the authenticator
4197 name). See chapter &<<CHAPSMTPAUTH>>& for a discussion of SMTP authentication.
4198 This option can be used with &%-bh%& and &%-bs%& to set up an
4199 authenticated SMTP session without actually using the SMTP AUTH command.
4201 .vitem &%-oMai%&&~<&'string'&>
4202 .oindex "&%-oMai%&"
4203 .cindex "authentication" "id, specifying for local message"
4204 See &%-oMa%& above for general remarks about the &%-oM%& options. The &%-oMai%&
4205 option sets the value of &$authenticated_id$& (the id that was authenticated).
4206 This overrides the default value (the caller's login id, except with &%-bh%&,
4207 where there is no default) for messages from local sources. See chapter
4208 &<<CHAPSMTPAUTH>>& for a discussion of authenticated ids.
4210 .vitem &%-oMas%&&~<&'address'&>
4211 .oindex "&%-oMas%&"
4212 .cindex "authentication" "sender, specifying for local message"
4213 See &%-oMa%& above for general remarks about the &%-oM%& options. The &%-oMas%&
4214 option sets the authenticated sender value in &$authenticated_sender$&. It
4215 overrides the sender address that is created from the caller's login id for
4216 messages from local sources, except when &%-bh%& is used, when there is no
4217 default. For both &%-bh%& and &%-bs%&, an authenticated sender that is
4218 specified on a MAIL command overrides this value. See chapter
4219 &<<CHAPSMTPAUTH>>& for a discussion of authenticated senders.
4221 .vitem &%-oMi%&&~<&'interface&~address'&>
4222 .oindex "&%-oMi%&"
4223 .cindex "interface" "address, specifying for local message"
4224 See &%-oMa%& above for general remarks about the &%-oM%& options. The &%-oMi%&
4225 option sets the IP interface address value. A port number may be included,
4226 using the same syntax as for &%-oMa%&. The interface address is placed in
4227 &$received_ip_address$& and the port number, if present, in &$received_port$&.
4229 .vitem &%-oMr%&&~<&'protocol&~name'&>
4230 .oindex "&%-oMr%&"
4231 .cindex "protocol, specifying for local message"
4232 .vindex "&$received_protocol$&"
4233 See &%-oMa%& above for general remarks about the &%-oM%& options. The &%-oMr%&
4234 option sets the received protocol value that is stored in
4235 &$received_protocol$&. However, it does not apply (and is ignored) when &%-bh%&
4236 or &%-bs%& is used. For &%-bh%&, the protocol is forced to one of the standard
4237 SMTP protocol names (see the description of &$received_protocol$& in section
4238 &<<SECTexpvar>>&). For &%-bs%&, the protocol is always &"local-"& followed by
4239 one of those same names. For &%-bS%& (batched SMTP) however, the protocol can
4240 be set by &%-oMr%&.
4242 .vitem &%-oMs%&&~<&'host&~name'&>
4243 .oindex "&%-oMs%&"
4244 .cindex "sender" "host name, specifying for local message"
4245 See &%-oMa%& above for general remarks about the &%-oM%& options. The &%-oMs%&
4246 option sets the sender host name in &$sender_host_name$&. When this option is
4247 present, Exim does not attempt to look up a host name from an IP address; it
4248 uses the name it is given.
4250 .vitem &%-oMt%&&~<&'ident&~string'&>
4251 .oindex "&%-oMt%&"
4252 .cindex "sender" "ident string, specifying for local message"
4253 See &%-oMa%& above for general remarks about the &%-oM%& options. The &%-oMt%&
4254 option sets the sender ident value in &$sender_ident$&. The default setting for
4255 local callers is the login id of the calling process, except when &%-bh%& is
4256 used, when there is no default.
4258 .vitem &%-om%&
4259 .oindex "&%-om%&"
4260 .cindex "Sendmail compatibility" "&%-om%& option ignored"
4261 In Sendmail, this option means &"me too"&, indicating that the sender of a
4262 message should receive a copy of the message if the sender appears in an alias
4263 expansion. Exim always does this, so the option does nothing.
4265 .vitem &%-oo%&
4266 .oindex "&%-oo%&"
4267 .cindex "Sendmail compatibility" "&%-oo%& option ignored"
4268 This option is ignored. In Sendmail it specifies &"old style headers"&,
4269 whatever that means.
4271 .vitem &%-oP%&&~<&'path'&>
4272 .oindex "&%-oP%&"
4273 .cindex "pid (process id)" "of daemon"
4274 .cindex "daemon" "process id (pid)"
4275 This option is useful only in conjunction with &%-bd%& or &%-q%& with a time
4276 value. The option specifies the file to which the process id of the daemon is
4277 written. When &%-oX%& is used with &%-bd%&, or when &%-q%& with a time is used
4278 without &%-bd%&, this is the only way of causing Exim to write a pid file,
4279 because in those cases, the normal pid file is not used.
4281 .vitem &%-or%&&~<&'time'&>
4282 .oindex "&%-or%&"
4283 .cindex "timeout" "for non-SMTP input"
4284 This option sets a timeout value for incoming non-SMTP messages. If it is not
4285 set, Exim will wait forever for the standard input. The value can also be set
4286 by the &%receive_timeout%& option. The format used for specifying times is
4287 described in section &<<SECTtimeformat>>&.
4289 .vitem &%-os%&&~<&'time'&>
4290 .oindex "&%-os%&"
4291 .cindex "timeout" "for SMTP input"
4292 .cindex "SMTP" "input timeout"
4293 This option sets a timeout value for incoming SMTP messages. The timeout
4294 applies to each SMTP command and block of data. The value can also be set by
4295 the &%smtp_receive_timeout%& option; it defaults to 5 minutes. The format used
4296 for specifying times is described in section &<<SECTtimeformat>>&.
4298 .vitem &%-ov%&
4299 .oindex "&%-ov%&"
4300 This option has exactly the same effect as &%-v%&.
4302 .vitem &%-oX%&&~<&'number&~or&~string'&>
4303 .oindex "&%-oX%&"
4304 .cindex "TCP/IP" "setting listening ports"
4305 .cindex "TCP/IP" "setting listening interfaces"
4306 .cindex "port" "receiving TCP/IP"
4307 This option is relevant only when the &%-bd%& (start listening daemon) option
4308 is also given. It controls which ports and interfaces the daemon uses. Details
4309 of the syntax, and how it interacts with configuration file options, are given
4310 in chapter &<<CHAPinterfaces>>&. When &%-oX%& is used to start a daemon, no pid
4311 file is written unless &%-oP%& is also present to specify a pid file name.
4313 .vitem &%-pd%&
4314 .oindex "&%-pd%&"
4315 .cindex "Perl" "starting the interpreter"
4316 This option applies when an embedded Perl interpreter is linked with Exim (see
4317 chapter &<<CHAPperl>>&). It overrides the setting of the &%perl_at_start%&
4318 option, forcing the starting of the interpreter to be delayed until it is
4319 needed.
4321 .vitem &%-ps%&
4322 .oindex "&%-ps%&"
4323 .cindex "Perl" "starting the interpreter"
4324 This option applies when an embedded Perl interpreter is linked with Exim (see
4325 chapter &<<CHAPperl>>&). It overrides the setting of the &%perl_at_start%&
4326 option, forcing the starting of the interpreter to occur as soon as Exim is
4327 started.
4329 .vitem &%-p%&<&'rval'&>:<&'sval'&>
4330 .oindex "&%-p%&"
4331 For compatibility with Sendmail, this option is equivalent to
4332 .display
4333 &`-oMr`& <&'rval'&> &`-oMs`& <&'sval'&>
4334 .endd
4335 It sets the incoming protocol and host name (for trusted callers). The
4336 host name and its colon can be omitted when only the protocol is to be set.
4337 Note the Exim already has two private options, &%-pd%& and &%-ps%&, that refer
4338 to embedded Perl. It is therefore impossible to set a protocol value of &`p`&
4339 or &`s`& using this option (but that does not seem a real limitation).
4341 .vitem &%-q%&
4342 .oindex "&%-q%&"
4343 .cindex "queue runner" "starting manually"
4344 This option is normally restricted to admin users. However, there is a
4345 configuration option called &%prod_requires_admin%& which can be set false to
4346 relax this restriction (and also the same requirement for the &%-M%&, &%-R%&,
4347 and &%-S%& options).
4349 .cindex "queue runner" "description of operation"
4350 The &%-q%& option starts one queue runner process. This scans the queue of
4351 waiting messages, and runs a delivery process for each one in turn. It waits
4352 for each delivery process to finish before starting the next one. A delivery
4353 process may not actually do any deliveries if the retry times for the addresses
4354 have not been reached. Use &%-qf%& (see below) if you want to override this.
4356 If
4357 .cindex "SMTP" "passed connection"
4358 .cindex "SMTP" "multiple deliveries"
4359 .cindex "multiple SMTP deliveries"
4360 the delivery process spawns other processes to deliver other messages down
4361 passed SMTP connections, the queue runner waits for these to finish before
4362 proceeding.
4364 When all the queued messages have been considered, the original queue runner
4365 process terminates. In other words, a single pass is made over the waiting
4366 mail, one message at a time. Use &%-q%& with a time (see below) if you want
4367 this to be repeated periodically.
4369 Exim processes the waiting messages in an unpredictable order. It isn't very
4370 random, but it is likely to be different each time, which is all that matters.
4371 If one particular message screws up a remote MTA, other messages to the same
4372 MTA have a chance of getting through if they get tried first.
4374 It is possible to cause the messages to be processed in lexical message id
4375 order, which is essentially the order in which they arrived, by setting the
4376 &%queue_run_in_order%& option, but this is not recommended for normal use.
4378 .vitem &%-q%&<&'qflags'&>
4379 The &%-q%& option may be followed by one or more flag letters that change its
4380 behaviour. They are all optional, but if more than one is present, they must
4381 appear in the correct order. Each flag is described in a separate item below.
4383 .vitem &%-qq...%&
4384 .oindex "&%-qq%&"
4385 .cindex "queue" "double scanning"
4386 .cindex "queue" "routing"
4387 .cindex "routing" "whole queue before delivery"
4388 An option starting with &%-qq%& requests a two-stage queue run. In the first
4389 stage, the queue is scanned as if the &%queue_smtp_domains%& option matched
4390 every domain. Addresses are routed, local deliveries happen, but no remote
4391 transports are run.
4393 .cindex "hints database" "remembering routing"
4394 The hints database that remembers which messages are waiting for specific hosts
4395 is updated, as if delivery to those hosts had been deferred. After this is
4396 complete, a second, normal queue scan happens, with routing and delivery taking
4397 place as normal. Messages that are routed to the same host should mostly be
4398 delivered down a single SMTP
4399 .cindex "SMTP" "passed connection"
4400 .cindex "SMTP" "multiple deliveries"
4401 .cindex "multiple SMTP deliveries"
4402 connection because of the hints that were set up during the first queue scan.
4403 This option may be useful for hosts that are connected to the Internet
4404 intermittently.
4406 .vitem &%-q[q]i...%&
4407 .oindex "&%-qi%&"
4408 .cindex "queue" "initial delivery"
4409 If the &'i'& flag is present, the queue runner runs delivery processes only for
4410 those messages that haven't previously been tried. (&'i'& stands for &"initial
4411 delivery"&.) This can be helpful if you are putting messages on the queue using
4412 &%-odq%& and want a queue runner just to process the new messages.
4414 .vitem &%-q[q][i]f...%&
4415 .oindex "&%-qf%&"
4416 .cindex "queue" "forcing delivery"
4417 .cindex "delivery" "forcing in queue run"
4418 If one &'f'& flag is present, a delivery attempt is forced for each non-frozen
4419 message, whereas without &'f'& only those non-frozen addresses that have passed
4420 their retry times are tried.
4422 .vitem &%-q[q][i]ff...%&
4423 .oindex "&%-qff%&"
4424 .cindex "frozen messages" "forcing delivery"
4425 If &'ff'& is present, a delivery attempt is forced for every message, whether
4426 frozen or not.
4428 .vitem &%-q[q][i][f[f]]l%&
4429 .oindex "&%-ql%&"
4430 .cindex "queue" "local deliveries only"
4431 The &'l'& (the letter &"ell"&) flag specifies that only local deliveries are to
4432 be done. If a message requires any remote deliveries, it remains on the queue
4433 for later delivery.
4435 .vitem &%-q%&<&'qflags'&>&~<&'start&~id'&>&~<&'end&~id'&>
4436 .cindex "queue" "delivering specific messages"
4437 When scanning the queue, Exim can be made to skip over messages whose ids are
4438 lexically less than a given value by following the &%-q%& option with a
4439 starting message id. For example:
4440 .code
4441 exim -q 0t5C6f-0000c8-00
4442 .endd
4443 Messages that arrived earlier than &`0t5C6f-0000c8-00`& are not inspected. If a
4444 second message id is given, messages whose ids are lexically greater than it
4445 are also skipped. If the same id is given twice, for example,
4446 .code
4447 exim -q 0t5C6f-0000c8-00 0t5C6f-0000c8-00
4448 .endd
4449 just one delivery process is started, for that message. This differs from
4450 &%-M%& in that retry data is respected, and it also differs from &%-Mc%& in
4451 that it counts as a delivery from a queue run. Note that the selection
4452 mechanism does not affect the order in which the messages are scanned. There
4453 are also other ways of selecting specific sets of messages for delivery in a
4454 queue run &-- see &%-R%& and &%-S%&.
4456 .vitem &%-q%&<&'qflags'&><&'time'&>
4457 .cindex "queue runner" "starting periodically"
4458 .cindex "periodic queue running"
4459 When a time value is present, the &%-q%& option causes Exim to run as a daemon,
4460 starting a queue runner process at intervals specified by the given time value
4461 (whose format is described in section &<<SECTtimeformat>>&). This form of the
4462 &%-q%& option is commonly combined with the &%-bd%& option, in which case a
4463 single daemon process handles both functions. A common way of starting up a
4464 combined daemon at system boot time is to use a command such as
4465 .code
4466 /usr/exim/bin/exim -bd -q30m
4467 .endd
4468 Such a daemon listens for incoming SMTP calls, and also starts a queue runner
4469 process every 30 minutes.
4471 When a daemon is started by &%-q%& with a time value, but without &%-bd%&, no
4472 pid file is written unless one is explicitly requested by the &%-oP%& option.
4474 .vitem &%-qR%&<&'rsflags'&>&~<&'string'&>
4475 .oindex "&%-qR%&"
4476 This option is synonymous with &%-R%&. It is provided for Sendmail
4477 compatibility.
4479 .vitem &%-qS%&<&'rsflags'&>&~<&'string'&>
4480 .oindex "&%-qS%&"
4481 This option is synonymous with &%-S%&.
4483 .vitem &%-R%&<&'rsflags'&>&~<&'string'&>
4484 .oindex "&%-R%&"
4485 .cindex "queue runner" "for specific recipients"
4486 .cindex "delivery" "to given domain"
4487 .cindex "domain" "delivery to"
4488 The <&'rsflags'&> may be empty, in which case the white space before the string
4489 is optional, unless the string is &'f'&, &'ff'&, &'r'&, &'rf'&, or &'rff'&,
4490 which are the possible values for <&'rsflags'&>. White space is required if
4491 <&'rsflags'&> is not empty.
4493 This option is similar to &%-q%& with no time value, that is, it causes Exim to
4494 perform a single queue run, except that, when scanning the messages on the
4495 queue, Exim processes only those that have at least one undelivered recipient
4496 address containing the given string, which is checked in a case-independent
4497 way. If the <&'rsflags'&> start with &'r'&, <&'string'&> is interpreted as a
4498 regular expression; otherwise it is a literal string.
4500 If you want to do periodic queue runs for messages with specific recipients,
4501 you can combine &%-R%& with &%-q%& and a time value. For example:
4502 .code
4503 exim -q25m -R @special.domain.example
4504 .endd
4505 This example does a queue run for messages with recipients in the given domain
4506 every 25 minutes. Any additional flags that are specified with &%-q%& are
4507 applied to each queue run.
4509 Once a message is selected for delivery by this mechanism, all its addresses
4510 are processed. For the first selected message, Exim overrides any retry
4511 information and forces a delivery attempt for each undelivered address. This
4512 means that if delivery of any address in the first message is successful, any
4513 existing retry information is deleted, and so delivery attempts for that
4514 address in subsequently selected messages (which are processed without forcing)
4515 will run. However, if delivery of any address does not succeed, the retry
4516 information is updated, and in subsequently selected messages, the failing
4517 address will be skipped.
4519 .cindex "frozen messages" "forcing delivery"
4520 If the <&'rsflags'&> contain &'f'& or &'ff'&, the delivery forcing applies to
4521 all selected messages, not just the first; frozen messages are included when
4522 &'ff'& is present.
4524 The &%-R%& option makes it straightforward to initiate delivery of all messages
4525 to a given domain after a host has been down for some time. When the SMTP
4526 command ETRN is accepted by its ACL (see chapter &<<CHAPACL>>&), its default
4527 effect is to run Exim with the &%-R%& option, but it can be configured to run
4528 an arbitrary command instead.
4530 .vitem &%-r%&
4531 .oindex "&%-r%&"
4532 This is a documented (for Sendmail) obsolete alternative name for &%-f%&.
4534 .vitem &%-S%&<&'rsflags'&>&~<&'string'&>
4535 .oindex "&%-S%&"
4536 .cindex "delivery" "from given sender"
4537 .cindex "queue runner" "for specific senders"
4538 This option acts like &%-R%& except that it checks the string against each
4539 message's sender instead of against the recipients. If &%-R%& is also set, both
4540 conditions must be met for a message to be selected. If either of the options
4541 has &'f'& or &'ff'& in its flags, the associated action is taken.
4543 .vitem &%-Tqt%&&~<&'times'&>
4544 .oindex "&%-Tqt%&"
4545 This is an option that is exclusively for use by the Exim testing suite. It is not
4546 recognized when Exim is run normally. It allows for the setting up of explicit
4547 &"queue times"& so that various warning/retry features can be tested.
4549 .vitem &%-t%&
4550 .oindex "&%-t%&"
4551 .cindex "recipient" "extracting from header lines"
4552 .cindex "&'Bcc:'& header line"
4553 .cindex "&'Cc:'& header line"
4554 .cindex "&'To:'& header line"
4555 When Exim is receiving a locally-generated, non-SMTP message on its standard
4556 input, the &%-t%& option causes the recipients of the message to be obtained
4557 from the &'To:'&, &'Cc:'&, and &'Bcc:'& header lines in the message instead of
4558 from the command arguments. The addresses are extracted before any rewriting
4559 takes place and the &'Bcc:'& header line, if present, is then removed.
4561 .cindex "Sendmail compatibility" "&%-t%& option"
4562 If the command has any arguments, they specify addresses to which the message
4563 is &'not'& to be delivered. That is, the argument addresses are removed from
4564 the recipients list obtained from the headers. This is compatible with Smail 3
4565 and in accordance with the documented behaviour of several versions of
4566 Sendmail, as described in man pages on a number of operating systems (e.g.
4567 Solaris 8, IRIX 6.5, HP-UX 11). However, some versions of Sendmail &'add'&
4568 argument addresses to those obtained from the headers, and the O'Reilly
4569 Sendmail book documents it that way. Exim can be made to add argument addresses
4570 instead of subtracting them by setting the option
4571 &%extract_addresses_remove_arguments%& false.
4573 .cindex "&%Resent-%& header lines" "with &%-t%&"
4574 If there are any &%Resent-%& header lines in the message, Exim extracts
4575 recipients from all &'Resent-To:'&, &'Resent-Cc:'&, and &'Resent-Bcc:'& header
4576 lines instead of from &'To:'&, &'Cc:'&, and &'Bcc:'&. This is for compatibility
4577 with Sendmail and other MTAs. (Prior to release 4.20, Exim gave an error if
4578 &%-t%& was used in conjunction with &%Resent-%& header lines.)
4580 RFC 2822 talks about different sets of &%Resent-%& header lines (for when a
4581 message is resent several times). The RFC also specifies that they should be
4582 added at the front of the message, and separated by &'Received:'& lines. It is
4583 not at all clear how &%-t%& should operate in the present of multiple sets,
4584 nor indeed exactly what constitutes a &"set"&.
4585 In practice, it seems that MUAs do not follow the RFC. The &%Resent-%& lines
4586 are often added at the end of the header, and if a message is resent more than
4587 once, it is common for the original set of &%Resent-%& headers to be renamed as
4588 &%X-Resent-%& when a new set is added. This removes any possible ambiguity.
4590 .vitem &%-ti%&
4591 .oindex "&%-ti%&"
4592 This option is exactly equivalent to &%-t%& &%-i%&. It is provided for
4593 compatibility with Sendmail.
4595 .vitem &%-tls-on-connect%&
4596 .oindex "&%-tls-on-connect%&"
4597 .cindex "TLS" "use without STARTTLS"
4598 .cindex "TLS" "automatic start"
4599 This option is available when Exim is compiled with TLS support. It forces all
4600 incoming SMTP connections to behave as if the incoming port is listed in the
4601 &%tls_on_connect_ports%& option. See section &<<SECTsupobssmt>>& and chapter
4602 &<<CHAPTLS>>& for further details.
4605 .vitem &%-U%&
4606 .oindex "&%-U%&"
4607 .cindex "Sendmail compatibility" "&%-U%& option ignored"
4608 Sendmail uses this option for &"initial message submission"&, and its
4609 documentation states that in future releases, it may complain about
4610 syntactically invalid messages rather than fixing them when this flag is not
4611 set. Exim ignores this option.
4613 .vitem &%-v%&
4614 .oindex "&%-v%&"
4615 This option causes Exim to write information to the standard error stream,
4616 describing what it is doing. In particular, it shows the log lines for
4617 receiving and delivering a message, and if an SMTP connection is made, the SMTP
4618 dialogue is shown. Some of the log lines shown may not actually be written to
4619 the log if the setting of &%log_selector%& discards them. Any relevant
4620 selectors are shown with each log line. If none are shown, the logging is
4621 unconditional.
4623 .vitem &%-x%&
4624 .oindex "&%-x%&"
4625 AIX uses &%-x%& for a private purpose (&"mail from a local mail program has
4626 National Language Support extended characters in the body of the mail item"&).
4627 It sets &%-x%& when calling the MTA from its &%mail%& command. Exim ignores
4628 this option.
4630 .new
4631 .vitem &%-X%&&~<&'logfile'&>
4632 .oindex "&%-X%&"
4633 This option is interpreted by Sendmail to cause debug information to be sent
4634 to the named file. It is ignored by Exim.
4635 .wen
4636 .endlist
4638 .ecindex IIDclo1
4639 .ecindex IIDclo2
4642 . ////////////////////////////////////////////////////////////////////////////
4643 . Insert a stylized DocBook comment here, to identify the end of the command
4644 . line options. This is for the benefit of the Perl script that automatically
4645 . creates a man page for the options.
4646 . ////////////////////////////////////////////////////////////////////////////
4648 .literal xml
4649 <!-- === End of command line options === -->
4650 .literal off
4656 . ////////////////////////////////////////////////////////////////////////////
4657 . ////////////////////////////////////////////////////////////////////////////
4660 .chapter "The Exim run time configuration file" "CHAPconf" &&&
4661 "The runtime configuration file"
4663 .cindex "run time configuration"
4664 .cindex "configuration file" "general description"
4665 .cindex "CONFIGURE_FILE"
4666 .cindex "configuration file" "errors in"
4667 .cindex "error" "in configuration file"
4668 .cindex "return code" "for bad configuration"
4669 Exim uses a single run time configuration file that is read whenever an Exim
4670 binary is executed. Note that in normal operation, this happens frequently,
4671 because Exim is designed to operate in a distributed manner, without central
4672 control.
4674 If a syntax error is detected while reading the configuration file, Exim
4675 writes a message on the standard error, and exits with a non-zero return code.
4676 The message is also written to the panic log. &*Note*&: Only simple syntax
4677 errors can be detected at this time. The values of any expanded options are
4678 not checked until the expansion happens, even when the expansion does not
4679 actually alter the string.
4681 The name of the configuration file is compiled into the binary for security
4682 reasons, and is specified by the CONFIGURE_FILE compilation option. In
4683 most configurations, this specifies a single file. However, it is permitted to
4684 give a colon-separated list of file names, in which case Exim uses the first
4685 existing file in the list.
4687 .cindex "EXIM_USER"
4688 .cindex "EXIM_GROUP"
4689 .cindex "CONFIGURE_OWNER"
4690 .cindex "CONFIGURE_GROUP"
4691 .cindex "configuration file" "ownership"
4692 .cindex "ownership" "configuration file"
4693 The run time configuration file must be owned by root or by the user that is
4694 specified at compile time by the CONFIGURE_OWNER option (if set). The
4695 configuration file must not be world-writeable, or group-writeable unless its
4696 group is the root group or the one specified at compile time by the
4697 CONFIGURE_GROUP option.
4699 &*Warning*&: In a conventional configuration, where the Exim binary is setuid
4700 to root, anybody who is able to edit the run time configuration file has an
4701 easy way to run commands as root. If you specify a user or group in the
4702 CONFIGURE_OWNER or CONFIGURE_GROUP options, then that user and/or any users
4703 who are members of that group will trivially be able to obtain root privileges.
4705 Up to Exim version 4.72, the run time configuration file was also permitted to
4706 be writeable by the Exim user and/or group. That has been changed in Exim 4.73
4707 since it offered a simple privilege escalation for any attacker who managed to
4708 compromise the Exim user account.
4710 A default configuration file, which will work correctly in simple situations,
4711 is provided in the file &_src/configure.default_&. If CONFIGURE_FILE
4712 defines just one file name, the installation process copies the default
4713 configuration to a new file of that name if it did not previously exist. If
4714 CONFIGURE_FILE is a list, no default is automatically installed. Chapter
4715 &<<CHAPdefconfil>>& is a &"walk-through"& discussion of the default
4716 configuration.
4720 .section "Using a different configuration file" "SECID40"
4721 .cindex "configuration file" "alternate"
4722 A one-off alternate configuration can be specified by the &%-C%& command line
4723 option, which may specify a single file or a list of files. However, when
4724 &%-C%& is used, Exim gives up its root privilege, unless called by root (or
4725 unless the argument for &%-C%& is identical to the built-in value from
4726 CONFIGURE_FILE), or is listed in the TRUSTED_CONFIG_LIST file and the caller
4727 is the Exim user or the user specified in the CONFIGURE_OWNER setting. &%-C%&
4728 is useful mainly for checking the syntax of configuration files before
4729 installing them. No owner or group checks are done on a configuration file
4730 specified by &%-C%&, if root privilege has been dropped.
4732 Even the Exim user is not trusted to specify an arbitrary configuration file
4733 with the &%-C%& option to be used with root privileges, unless that file is
4734 listed in the TRUSTED_CONFIG_LIST file. This locks out the possibility of
4735 testing a configuration using &%-C%& right through message reception and
4736 delivery, even if the caller is root. The reception works, but by that time,
4737 Exim is running as the Exim user, so when it re-execs to regain privilege for
4738 the delivery, the use of &%-C%& causes privilege to be lost. However, root
4739 can test reception and delivery using two separate commands (one to put a
4740 message on the queue, using &%-odq%&, and another to do the delivery, using
4741 &%-M%&).
4743 If ALT_CONFIG_PREFIX is defined &_in Local/Makefile_&, it specifies a
4744 prefix string with which any file named in a &%-C%& command line option must
4745 start. In addition, the file name must not contain the sequence &"&`/../`&"&.
4746 There is no default setting for ALT_CONFIG_PREFIX; when it is unset, any file
4747 name can be used with &%-C%&.
4749 One-off changes to a configuration can be specified by the &%-D%& command line
4750 option, which defines and overrides values for macros used inside the
4751 configuration file. However, like &%-C%&, the use of this option by a
4752 non-privileged user causes Exim to discard its root privilege.
4753 If DISABLE_D_OPTION is defined in &_Local/Makefile_&, the use of &%-D%& is
4754 completely disabled, and its use causes an immediate error exit.
4756 The WHITELIST_D_MACROS option in &_Local/Makefile_& permits the binary builder
4757 to declare certain macro names trusted, such that root privilege will not
4758 necessarily be discarded.
4759 WHITELIST_D_MACROS defines a colon-separated list of macros which are
4760 considered safe and, if &%-D%& only supplies macros from this list, and the
4761 values are acceptable, then Exim will not give up root privilege if the caller
4762 is root, the Exim run-time user, or the CONFIGURE_OWNER, if set. This is a
4763 transition mechanism and is expected to be removed in the future. Acceptable
4764 values for the macros satisfy the regexp: &`^[A-Za-z0-9_/.-]*$`&
4766 Some sites may wish to use the same Exim binary on different machines that
4767 share a file system, but to use different configuration files on each machine.
4768 If CONFIGURE_FILE_USE_NODE is defined in &_Local/Makefile_&, Exim first
4769 looks for a file whose name is the configuration file name followed by a dot
4770 and the machine's node name, as obtained from the &[uname()]& function. If this
4771 file does not exist, the standard name is tried. This processing occurs for
4772 each file name in the list given by CONFIGURE_FILE or &%-C%&.
4774 In some esoteric situations different versions of Exim may be run under
4775 different effective uids and the CONFIGURE_FILE_USE_EUID is defined to
4776 help with this. See the comments in &_src/EDITME_& for details.
4780 .section "Configuration file format" "SECTconffilfor"
4781 .cindex "configuration file" "format of"
4782 .cindex "format" "configuration file"
4783 Exim's configuration file is divided into a number of different parts. General
4784 option settings must always appear at the start of the file. The other parts
4785 are all optional, and may appear in any order. Each part other than the first
4786 is introduced by the word &"begin"& followed by the name of the part. The
4787 optional parts are:
4789 .ilist
4790 &'ACL'&: Access control lists for controlling incoming SMTP mail (see chapter
4791 &<<CHAPACL>>&).
4792 .next
4793 .cindex "AUTH" "configuration"
4794 &'authenticators'&: Configuration settings for the authenticator drivers. These
4795 are concerned with the SMTP AUTH command (see chapter &<<CHAPSMTPAUTH>>&).
4796 .next
4797 &'routers'&: Configuration settings for the router drivers. Routers process
4798 addresses and determine how the message is to be delivered (see chapters
4799 &<<CHAProutergeneric>>&&--&<<CHAPredirect>>&).
4800 .next
4801 &'transports'&: Configuration settings for the transport drivers. Transports
4802 define mechanisms for copying messages to destinations (see chapters
4803 &<<CHAPtransportgeneric>>&&--&<<CHAPsmtptrans>>&).
4804 .next
4805 &'retry'&: Retry rules, for use when a message cannot be delivered immediately.
4806 If there is no retry section, or if it is empty (that is, no retry rules are
4807 defined), Exim will not retry deliveries. In this situation, temporary errors
4808 are treate