Docs: emphasize that the smtp_connection log selector applies to inbound
[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 "4.85"
49 .include ./local_params
51 .set ACL "access control lists (ACLs)"
52 .set I "&nbsp;&nbsp;&nbsp;&nbsp;"
54 .macro copyyear
55 2015
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 .versiondatexml
183 <authorinitials>EM</authorinitials>
184 </revision></revhistory>
185 <copyright><year>
186 .copyyear
187 </year><holder>University of Cambridge</holder></copyright>
188 </bookinfo>
189 .literal off
192 . /////////////////////////////////////////////////////////////////////////////
193 . This chunk of literal XML implements index entries of the form "x, see y" and
194 . "x, see also y". However, the DocBook DTD doesn't allow <indexterm> entries
195 . at the top level, so we have to put the .chapter directive first.
196 . /////////////////////////////////////////////////////////////////////////////
198 .chapter "Introduction" "CHID1"
199 .literal xml
201 <indexterm role="variable">
202 <primary>$1, $2, etc.</primary>
203 <see><emphasis>numerical variables</emphasis></see>
204 </indexterm>
205 <indexterm role="concept">
206 <primary>address</primary>
207 <secondary>rewriting</secondary>
208 <see><emphasis>rewriting</emphasis></see>
209 </indexterm>
210 <indexterm role="concept">
211 <primary>Bounce Address Tag Validation</primary>
212 <see><emphasis>BATV</emphasis></see>
213 </indexterm>
214 <indexterm role="concept">
215 <primary>Client SMTP Authorization</primary>
216 <see><emphasis>CSA</emphasis></see>
217 </indexterm>
218 <indexterm role="concept">
219 <primary>CR character</primary>
220 <see><emphasis>carriage return</emphasis></see>
221 </indexterm>
222 <indexterm role="concept">
223 <primary>CRL</primary>
224 <see><emphasis>certificate revocation list</emphasis></see>
225 </indexterm>
226 <indexterm role="concept">
227 <primary>delivery</primary>
228 <secondary>failure report</secondary>
229 <see><emphasis>bounce message</emphasis></see>
230 </indexterm>
231 <indexterm role="concept">
232 <primary>dialup</primary>
233 <see><emphasis>intermittently connected hosts</emphasis></see>
234 </indexterm>
235 <indexterm role="concept">
236 <primary>exiscan</primary>
237 <see><emphasis>content scanning</emphasis></see>
238 </indexterm>
239 <indexterm role="concept">
240 <primary>failover</primary>
241 <see><emphasis>fallback</emphasis></see>
242 </indexterm>
243 <indexterm role="concept">
244 <primary>fallover</primary>
245 <see><emphasis>fallback</emphasis></see>
246 </indexterm>
247 <indexterm role="concept">
248 <primary>filter</primary>
249 <secondary>Sieve</secondary>
250 <see><emphasis>Sieve filter</emphasis></see>
251 </indexterm>
252 <indexterm role="concept">
253 <primary>ident</primary>
254 <see><emphasis>RFC 1413</emphasis></see>
255 </indexterm>
256 <indexterm role="concept">
257 <primary>LF character</primary>
258 <see><emphasis>linefeed</emphasis></see>
259 </indexterm>
260 <indexterm role="concept">
261 <primary>maximum</primary>
262 <seealso><emphasis>limit</emphasis></seealso>
263 </indexterm>
264 <indexterm role="concept">
265 <primary>monitor</primary>
266 <see><emphasis>Exim monitor</emphasis></see>
267 </indexterm>
268 <indexterm role="concept">
269 <primary>no_<emphasis>xxx</emphasis></primary>
270 <see>entry for xxx</see>
271 </indexterm>
272 <indexterm role="concept">
273 <primary>NUL</primary>
274 <see><emphasis>binary zero</emphasis></see>
275 </indexterm>
276 <indexterm role="concept">
277 <primary>passwd file</primary>
278 <see><emphasis>/etc/passwd</emphasis></see>
279 </indexterm>
280 <indexterm role="concept">
281 <primary>process id</primary>
282 <see><emphasis>pid</emphasis></see>
283 </indexterm>
284 <indexterm role="concept">
285 <primary>RBL</primary>
286 <see><emphasis>DNS list</emphasis></see>
287 </indexterm>
288 <indexterm role="concept">
289 <primary>redirection</primary>
290 <see><emphasis>address redirection</emphasis></see>
291 </indexterm>
292 <indexterm role="concept">
293 <primary>return path</primary>
294 <seealso><emphasis>envelope sender</emphasis></seealso>
295 </indexterm>
296 <indexterm role="concept">
297 <primary>scanning</primary>
298 <see><emphasis>content scanning</emphasis></see>
299 </indexterm>
300 <indexterm role="concept">
301 <primary>SSL</primary>
302 <see><emphasis>TLS</emphasis></see>
303 </indexterm>
304 <indexterm role="concept">
305 <primary>string</primary>
306 <secondary>expansion</secondary>
307 <see><emphasis>expansion</emphasis></see>
308 </indexterm>
309 <indexterm role="concept">
310 <primary>top bit</primary>
311 <see><emphasis>8-bit characters</emphasis></see>
312 </indexterm>
313 <indexterm role="concept">
314 <primary>variables</primary>
315 <see><emphasis>expansion, variables</emphasis></see>
316 </indexterm>
317 <indexterm role="concept">
318 <primary>zero, binary</primary>
319 <see><emphasis>binary zero</emphasis></see>
320 </indexterm>
322 .literal off
325 . /////////////////////////////////////////////////////////////////////////////
326 . This is the real start of the first chapter. See the comment above as to why
327 . we can't have the .chapter line here.
328 . chapter "Introduction"
329 . /////////////////////////////////////////////////////////////////////////////
331 Exim is a mail transfer agent (MTA) for hosts that are running Unix or
332 Unix-like operating systems. It was designed on the assumption that it would be
333 run on hosts that are permanently connected to the Internet. However, it can be
334 used on intermittently connected hosts with suitable configuration adjustments.
336 Configuration files currently exist for the following operating systems: AIX,
337 BSD/OS (aka BSDI), Darwin (Mac OS X), DGUX, Dragonfly, FreeBSD, GNU/Hurd,
338 GNU/Linux, HI-OSF (Hitachi), HI-UX, HP-UX, IRIX, MIPS RISCOS, NetBSD, OpenBSD,
339 OpenUNIX, QNX, SCO, SCO SVR4.2 (aka UNIX-SV), Solaris (aka SunOS5), SunOS4,
340 Tru64-Unix (formerly Digital UNIX, formerly DEC-OSF1), Ultrix, and Unixware.
341 Some of these operating systems are no longer current and cannot easily be
342 tested, so the configuration files may no longer work in practice.
344 There are also configuration files for compiling Exim in the Cygwin environment
345 that can be installed on systems running Windows. However, this document does
346 not contain any information about running Exim in the Cygwin environment.
348 The terms and conditions for the use and distribution of Exim are contained in
349 the file &_NOTICE_&. Exim is distributed under the terms of the GNU General
350 Public Licence, a copy of which may be found in the file &_LICENCE_&.
352 The use, supply or promotion of Exim for the purpose of sending bulk,
353 unsolicited electronic mail is incompatible with the basic aims of the program,
354 which revolve around the free provision of a service that enhances the quality
355 of personal communications. The author of Exim regards indiscriminate
356 mass-mailing as an antisocial, irresponsible abuse of the Internet.
358 Exim owes a great deal to Smail 3 and its author, Ron Karr. Without the
359 experience of running and working on the Smail 3 code, I could never have
360 contemplated starting to write a new MTA. Many of the ideas and user interfaces
361 were originally taken from Smail 3, though the actual code of Exim is entirely
362 new, and has developed far beyond the initial concept.
364 Many people, both in Cambridge and around the world, have contributed to the
365 development and the testing of Exim, and to porting it to various operating
366 systems. I am grateful to them all. The distribution now contains a file called
367 &_ACKNOWLEDGMENTS_&, in which I have started recording the names of
368 contributors.
371 .section "Exim documentation" "SECID1"
372 . Keep this example change bar when updating the documentation!
374 .new
375 .cindex "documentation"
376 This edition of the Exim specification applies to version &version() of Exim.
377 Substantive changes from the &previousversion; edition are marked in some
378 renditions of the document; this paragraph is so marked if the rendition is
379 capable of showing a change indicator.
380 .wen
382 This document is very much a reference manual; it is not a tutorial. The reader
383 is expected to have some familiarity with the SMTP mail transfer protocol and
384 with general Unix system administration. Although there are some discussions
385 and examples in places, the information is mostly organized in a way that makes
386 it easy to look up, rather than in a natural order for sequential reading.
387 Furthermore, the manual aims to cover every aspect of Exim in detail, including
388 a number of rarely-used, special-purpose features that are unlikely to be of
389 very wide interest.
391 .cindex "books about Exim"
392 An &"easier"& discussion of Exim which provides more in-depth explanatory,
393 introductory, and tutorial material can be found in a book entitled &'The Exim
394 SMTP Mail Server'& (second edition, 2007), published by UIT Cambridge
395 (&url(
397 This book also contains a chapter that gives a general introduction to SMTP and
398 Internet mail. Inevitably, however, the book is unlikely to be fully up-to-date
399 with the latest release of Exim. (Note that the earlier book about Exim,
400 published by O'Reilly, covers Exim 3, and many things have changed in Exim 4.)
402 .cindex "Debian" "information sources"
403 If you are using a Debian distribution of Exim, you will find information about
404 Debian-specific features in the file
405 &_/usr/share/doc/exim4-base/README.Debian_&.
406 The command &(man update-exim.conf)& is another source of Debian-specific
407 information.
409 .cindex "&_doc/NewStuff_&"
410 .cindex "&_doc/ChangeLog_&"
411 .cindex "change log"
412 As the program develops, there may be features in newer versions that have not
413 yet made it into this document, which is updated only when the most significant
414 digit of the fractional part of the version number changes. Specifications of
415 new features that are not yet in this manual are placed in the file
416 &_doc/NewStuff_& in the Exim distribution.
418 Some features may be classified as &"experimental"&. These may change
419 incompatibly while they are developing, or even be withdrawn. For this reason,
420 they are not documented in this manual. Information about experimental features
421 can be found in the file &_doc/experimental.txt_&.
423 All changes to the program (whether new features, bug fixes, or other kinds of
424 change) are noted briefly in the file called &_doc/ChangeLog_&.
426 .cindex "&_doc/spec.txt_&"
427 This specification itself is available as an ASCII file in &_doc/spec.txt_& so
428 that it can easily be searched with a text editor. Other files in the &_doc_&
429 directory are:
431 .table2 100pt
432 .row &_OptionLists.txt_& "list of all options in alphabetical order"
433 .row &_dbm.discuss.txt_& "discussion about DBM libraries"
434 .row &_exim.8_& "a man page of Exim's command line options"
435 .row &_experimental.txt_& "documentation of experimental features"
436 .row &_filter.txt_& "specification of the filter language"
437 .row &_Exim3.upgrade_& "upgrade notes from release 2 to release 3"
438 .row &_Exim4.upgrade_& "upgrade notes from release 3 to release 4"
439 .endtable
441 The main specification and the specification of the filtering language are also
442 available in other formats (HTML, PostScript, PDF, and Texinfo). Section
443 &<<SECTavail>>& below tells you how to get hold of these.
447 .section "FTP and web sites" "SECID2"
448 .cindex "web site"
449 .cindex "FTP site"
450 The primary site for Exim source distributions is currently the University of
451 Cambridge's FTP site, whose contents are described in &'Where to find the Exim
452 distribution'& below. In addition, there is a web site and an FTP site at
453 & These are now also hosted at the University of Cambridge. The
454 & site was previously hosted for a number of years by Energis
455 Squared, formerly Planet Online Ltd, whose support I gratefully acknowledge.
457 .cindex "wiki"
458 .cindex "FAQ"
459 As well as Exim distribution tar files, the Exim web site contains a number of
460 differently formatted versions of the documentation. A recent addition to the
461 online information is the Exim wiki (&url(,
462 which contains what used to be a separate FAQ, as well as various other
463 examples, tips, and know-how that have been contributed by Exim users.
465 .cindex Bugzilla
466 An Exim Bugzilla exists at &url( You can use
467 this to report bugs, and also to add items to the wish list. Please search
468 first to check that you are not duplicating a previous entry.
472 .section "Mailing lists" "SECID3"
473 .cindex "mailing lists" "for Exim users"
474 The following Exim mailing lists exist:
476 .table2 140pt
477 .row &''& "Moderated, low volume announcements list"
478 .row &''& "General discussion list"
479 .row &''& "Discussion of bugs, enhancements, etc."
480 .row &''& "Automated commit messages from the VCS"
481 .endtable
483 You can subscribe to these lists, change your existing subscriptions, and view
484 or search the archives via the mailing lists link on the Exim home page.
485 .cindex "Debian" "mailing list for"
486 If you are using a Debian distribution of Exim, you may wish to subscribe to
487 the Debian-specific mailing list &''&
488 via this web page:
489 .display
490 &url(
491 .endd
492 Please ask Debian-specific questions on this list and not on the general Exim
493 lists.
495 .section "Exim training" "SECID4"
496 .cindex "training courses"
497 Training courses in Cambridge (UK) used to be run annually by the author of
498 Exim, before he retired. At the time of writing, there are no plans to run
499 further Exim courses in Cambridge. However, if that changes, relevant
500 information will be posted at &url(
502 .section "Bug reports" "SECID5"
503 .cindex "bug reports"
504 .cindex "reporting bugs"
505 Reports of obvious bugs can be emailed to &''& or reported
506 via the Bugzilla (&url( However, if you are unsure
507 whether some behaviour is a bug or not, the best thing to do is to post a
508 message to the &'exim-dev'& mailing list and have it discussed.
512 .section "Where to find the Exim distribution" "SECTavail"
513 .cindex "FTP site"
514 .cindex "distribution" "ftp site"
515 The master ftp site for the Exim distribution is
516 .display
517 &**&
518 .endd
519 This is mirrored by
520 .display
521 &**&
522 .endd
523 The file references that follow are relative to the &_exim_& directories at
524 these sites. There are now quite a number of independent mirror sites around
525 the world. Those that I know about are listed in the file called &_Mirrors_&.
527 Within the &_exim_& directory there are subdirectories called &_exim3_& (for
528 previous Exim 3 distributions), &_exim4_& (for the latest Exim 4
529 distributions), and &_Testing_& for testing versions. In the &_exim4_&
530 subdirectory, the current release can always be found in files called
531 .display
532 &_exim-n.nn.tar.gz_&
533 &_exim-n.nn.tar.bz2_&
534 .endd
535 where &'n.nn'& is the highest such version number in the directory. The two
536 files contain identical data; the only difference is the type of compression.
537 The &_.bz2_& file is usually a lot smaller than the &_.gz_& file.
539 .cindex "distribution" "signing details"
540 .cindex "distribution" "public key"
541 .cindex "public key for signed distribution"
542 The distributions will be PGP signed by an individual key of the Release
543 Coordinator. This key will have a uid containing an email address in the
544 &''& domain and will have signatures from other people, including
545 other Exim maintainers. We expect that the key will be in the "strong set" of
546 PGP keys. There should be a trust path to that key from Nigel Metheringham's
547 PGP key, a version of which can be found in the release directory in the file
548 &_nigel-pubkey.asc_&. All keys used will be available in public keyserver pools,
549 such as &''&.
551 At time of last update, releases were being made by Phil Pennock and signed with
552 key &'0x403043153903637F'&, although that key is expected to be replaced in 2013.
553 A trust path from Nigel's key to Phil's can be observed at
554 &url(
556 Releases have also been authorized to be performed by Todd Lyons who signs with
557 key &'0xC4F4F94804D29EBA'&. A direct trust path exists between previous RE Phil
558 Pennock and Todd Lyons through a common associate.
560 The signatures for the tar bundles are in:
561 .display
562 &_exim-n.nn.tar.gz.asc_&
563 &_exim-n.nn.tar.bz2.asc_&
564 .endd
565 For each released version, the log of changes is made separately available in a
566 separate file in the directory &_ChangeLogs_& so that it is possible to
567 find out what has changed without having to download the entire distribution.
569 .cindex "documentation" "available formats"
570 The main distribution contains ASCII versions of this specification and other
571 documentation; other formats of the documents are available in separate files
572 inside the &_exim4_& directory of the FTP site:
573 .display
574 &_exim-html-n.nn.tar.gz_&
575 &_exim-pdf-n.nn.tar.gz_&
576 &_exim-postscript-n.nn.tar.gz_&
577 &_exim-texinfo-n.nn.tar.gz_&
578 .endd
579 These tar files contain only the &_doc_& directory, not the complete
580 distribution, and are also available in &_.bz2_& as well as &_.gz_& forms.
583 .section "Limitations" "SECID6"
584 .ilist
585 .cindex "limitations of Exim"
586 .cindex "bang paths" "not handled by Exim"
587 Exim is designed for use as an Internet MTA, and therefore handles addresses in
588 RFC 2822 domain format only. It cannot handle UUCP &"bang paths"&, though
589 simple two-component bang paths can be converted by a straightforward rewriting
590 configuration. This restriction does not prevent Exim from being interfaced to
591 UUCP as a transport mechanism, provided that domain addresses are used.
592 .next
593 .cindex "domainless addresses"
594 .cindex "address" "without domain"
595 Exim insists that every address it handles has a domain attached. For incoming
596 local messages, domainless addresses are automatically qualified with a
597 configured domain value. Configuration options specify from which remote
598 systems unqualified addresses are acceptable. These are then qualified on
599 arrival.
600 .next
601 .cindex "transport" "external"
602 .cindex "external transports"
603 The only external transport mechanisms that are currently implemented are SMTP
604 and LMTP over a TCP/IP network (including support for IPv6). However, a pipe
605 transport is available, and there are facilities for writing messages to files
606 and pipes, optionally in &'batched SMTP'& format; these facilities can be used
607 to send messages to other transport mechanisms such as UUCP, provided they can
608 handle domain-style addresses. Batched SMTP input is also catered for.
609 .next
610 Exim is not designed for storing mail for dial-in hosts. When the volumes of
611 such mail are large, it is better to get the messages &"delivered"& into files
612 (that is, off Exim's queue) and subsequently passed on to the dial-in hosts by
613 other means.
614 .next
615 Although Exim does have basic facilities for scanning incoming messages, these
616 are not comprehensive enough to do full virus or spam scanning. Such operations
617 are best carried out using additional specialized software packages. If you
618 compile Exim with the content-scanning extension, straightforward interfaces to
619 a number of common scanners are provided.
620 .endlist
623 .section "Run time configuration" "SECID7"
624 Exim's run time configuration is held in a single text file that is divided
625 into a number of sections. The entries in this file consist of keywords and
626 values, in the style of Smail 3 configuration files. A default configuration
627 file which is suitable for simple online installations is provided in the
628 distribution, and is described in chapter &<<CHAPdefconfil>>& below.
631 .section "Calling interface" "SECID8"
632 .cindex "Sendmail compatibility" "command line interface"
633 Like many MTAs, Exim has adopted the Sendmail command line interface so that it
634 can be a straight replacement for &_/usr/lib/sendmail_& or
635 &_/usr/sbin/sendmail_& when sending mail, but you do not need to know anything
636 about Sendmail in order to run Exim. For actions other than sending messages,
637 Sendmail-compatible options also exist, but those that produce output (for
638 example, &%-bp%&, which lists the messages on the queue) do so in Exim's own
639 format. There are also some additional options that are compatible with Smail
640 3, and some further options that are new to Exim. Chapter &<<CHAPcommandline>>&
641 documents all Exim's command line options. This information is automatically
642 made into the man page that forms part of the Exim distribution.
644 Control of messages on the queue can be done via certain privileged command
645 line options. There is also an optional monitor program called &'eximon'&,
646 which displays current information in an X window, and which contains a menu
647 interface to Exim's command line administration options.
651 .section "Terminology" "SECID9"
652 .cindex "terminology definitions"
653 .cindex "body of message" "definition of"
654 The &'body'& of a message is the actual data that the sender wants to transmit.
655 It is the last part of a message, and is separated from the &'header'& (see
656 below) by a blank line.
658 .cindex "bounce message" "definition of"
659 When a message cannot be delivered, it is normally returned to the sender in a
660 delivery failure message or a &"non-delivery report"& (NDR). The term
661 &'bounce'& is commonly used for this action, and the error reports are often
662 called &'bounce messages'&. This is a convenient shorthand for &"delivery
663 failure error report"&. Such messages have an empty sender address in the
664 message's &'envelope'& (see below) to ensure that they cannot themselves give
665 rise to further bounce messages.
667 The term &'default'& appears frequently in this manual. It is used to qualify a
668 value which is used in the absence of any setting in the configuration. It may
669 also qualify an action which is taken unless a configuration setting specifies
670 otherwise.
672 The term &'defer'& is used when the delivery of a message to a specific
673 destination cannot immediately take place for some reason (a remote host may be
674 down, or a user's local mailbox may be full). Such deliveries are &'deferred'&
675 until a later time.
677 The word &'domain'& is sometimes used to mean all but the first component of a
678 host's name. It is &'not'& used in that sense here, where it normally refers to
679 the part of an email address following the @ sign.
681 .cindex "envelope, definition of"
682 .cindex "sender" "definition of"
683 A message in transit has an associated &'envelope'&, as well as a header and a
684 body. The envelope contains a sender address (to which bounce messages should
685 be delivered), and any number of recipient addresses. References to the
686 sender or the recipients of a message usually mean the addresses in the
687 envelope. An MTA uses these addresses for delivery, and for returning bounce
688 messages, not the addresses that appear in the header lines.
690 .cindex "message" "header, definition of"
691 .cindex "header section" "definition of"
692 The &'header'& of a message is the first part of a message's text, consisting
693 of a number of lines, each of which has a name such as &'From:'&, &'To:'&,
694 &'Subject:'&, etc. Long header lines can be split over several text lines by
695 indenting the continuations. The header is separated from the body by a blank
696 line.
698 .cindex "local part" "definition of"
699 .cindex "domain" "definition of"
700 The term &'local part'&, which is taken from RFC 2822, is used to refer to that
701 part of an email address that precedes the @ sign. The part that follows the
702 @ sign is called the &'domain'& or &'mail domain'&.
704 .cindex "local delivery" "definition of"
705 .cindex "remote delivery, definition of"
706 The terms &'local delivery'& and &'remote delivery'& are used to distinguish
707 delivery to a file or a pipe on the local host from delivery by SMTP over
708 TCP/IP to another host. As far as Exim is concerned, all hosts other than the
709 host it is running on are &'remote'&.
711 .cindex "return path" "definition of"
712 &'Return path'& is another name that is used for the sender address in a
713 message's envelope.
715 .cindex "queue" "definition of"
716 The term &'queue'& is used to refer to the set of messages awaiting delivery,
717 because this term is in widespread use in the context of MTAs. However, in
718 Exim's case the reality is more like a pool than a queue, because there is
719 normally no ordering of waiting messages.
721 .cindex "queue runner" "definition of"
722 The term &'queue runner'& is used to describe a process that scans the queue
723 and attempts to deliver those messages whose retry times have come. This term
724 is used by other MTAs, and also relates to the command &%runq%&, but in Exim
725 the waiting messages are normally processed in an unpredictable order.
727 .cindex "spool directory" "definition of"
728 The term &'spool directory'& is used for a directory in which Exim keeps the
729 messages on its queue &-- that is, those that it is in the process of
730 delivering. This should not be confused with the directory in which local
731 mailboxes are stored, which is called a &"spool directory"& by some people. In
732 the Exim documentation, &"spool"& is always used in the first sense.
739 . ////////////////////////////////////////////////////////////////////////////
740 . ////////////////////////////////////////////////////////////////////////////
742 .chapter "Incorporated code" "CHID2"
743 .cindex "incorporated code"
744 .cindex "regular expressions" "library"
745 .cindex "PCRE"
746 .cindex "OpenDMARC"
747 A number of pieces of external code are included in the Exim distribution.
749 .ilist
750 Regular expressions are supported in the main Exim program and in the
751 Exim monitor using the freely-distributable PCRE library, copyright
752 &copy; University of Cambridge. The source to PCRE is no longer shipped with
753 Exim, so you will need to use the version of PCRE shipped with your system,
754 or obtain and install the full version of the library from
755 &url(
756 .next
757 .cindex "cdb" "acknowledgment"
758 Support for the cdb (Constant DataBase) lookup method is provided by code
759 contributed by Nigel Metheringham of (at the time he contributed it) Planet
760 Online Ltd. The implementation is completely contained within the code of Exim.
761 It does not link against an external cdb library. The code contains the
762 following statements:
764 .blockquote
765 Copyright &copy; 1998 Nigel Metheringham, Planet Online Ltd
767 This program is free software; you can redistribute it and/or modify it under
768 the terms of the GNU General Public License as published by the Free Software
769 Foundation; either version 2 of the License, or (at your option) any later
770 version.
771 This code implements Dan Bernstein's Constant DataBase (cdb) spec. Information,
772 the spec and sample code for cdb can be obtained from
773 &url( This implementation borrows
774 some code from Dan Bernstein's implementation (which has no license
775 restrictions applied to it).
776 .endblockquote
777 .next
778 .cindex "SPA authentication"
779 .cindex "Samba project"
780 .cindex "Microsoft Secure Password Authentication"
781 Client support for Microsoft's &'Secure Password Authentication'& is provided
782 by code contributed by Marc Prud'hommeaux. Server support was contributed by
783 Tom Kistner. This includes code taken from the Samba project, which is released
784 under the Gnu GPL.
785 .next
786 .cindex "Cyrus"
787 .cindex "&'pwcheck'& daemon"
788 .cindex "&'pwauthd'& daemon"
789 Support for calling the Cyrus &'pwcheck'& and &'saslauthd'& daemons is provided
790 by code taken from the Cyrus-SASL library and adapted by Alexander S.
791 Sabourenkov. The permission notice appears below, in accordance with the
792 conditions expressed therein.
794 .blockquote
795 Copyright &copy; 2001 Carnegie Mellon University. All rights reserved.
797 Redistribution and use in source and binary forms, with or without
798 modification, are permitted provided that the following conditions
799 are met:
801 .olist
802 Redistributions of source code must retain the above copyright
803 notice, this list of conditions and the following disclaimer.
804 .next
805 Redistributions in binary form must reproduce the above copyright
806 notice, this list of conditions and the following disclaimer in
807 the documentation and/or other materials provided with the
808 distribution.
809 .next
810 The name &"Carnegie Mellon University"& must not be used to
811 endorse or promote products derived from this software without
812 prior written permission. For permission or any other legal
813 details, please contact
814 .display
815 Office of Technology Transfer
816 Carnegie Mellon University
817 5000 Forbes Avenue
818 Pittsburgh, PA 15213-3890
819 (412) 268-4387, fax: (412) 268-7395
821 .endd
822 .next
823 Redistributions of any form whatsoever must retain the following
824 acknowledgment:
826 &"This product includes software developed by Computing Services
827 at Carnegie Mellon University (&url("&
836 .endlist
837 .endblockquote
839 .next
840 .cindex "Exim monitor" "acknowledgment"
841 .cindex "X-windows"
842 .cindex "Athena"
843 The Exim Monitor program, which is an X-Window application, includes
844 modified versions of the Athena StripChart and TextPop widgets.
845 This code is copyright by DEC and MIT, and their permission notice appears
846 below, in accordance with the conditions expressed therein.
848 .blockquote
849 Copyright 1987, 1988 by Digital Equipment Corporation, Maynard, Massachusetts,
850 and the Massachusetts Institute of Technology, Cambridge, Massachusetts.
852 All Rights Reserved
854 Permission to use, copy, modify, and distribute this software and its
855 documentation for any purpose and without fee is hereby granted,
856 provided that the above copyright notice appear in all copies and that
857 both that copyright notice and this permission notice appear in
858 supporting documentation, and that the names of Digital or MIT not be
859 used in advertising or publicity pertaining to distribution of the
860 software without specific, written prior permission.
869 .endblockquote
871 .next
872 .cindex "opendmarc" "acknowledgment"
873 The DMARC implementation uses the OpenDMARC library which is Copyrighted by
874 The Trusted Domain Project. Portions of Exim source which use OpenDMARC
875 derived code are indicated in the respective source files. The full OpenDMARC
876 license is provided in the LICENSE.opendmarc file contained in the distributed
877 source code.
879 .next
880 Many people have contributed code fragments, some large, some small, that were
881 not covered by any specific licence requirements. It is assumed that the
882 contributors are happy to see their code incorporated into Exim under the GPL.
883 .endlist
889 . ////////////////////////////////////////////////////////////////////////////
890 . ////////////////////////////////////////////////////////////////////////////
892 .chapter "How Exim receives and delivers mail" "CHID11" &&&
893 "Receiving and delivering mail"
896 .section "Overall philosophy" "SECID10"
897 .cindex "design philosophy"
898 Exim is designed to work efficiently on systems that are permanently connected
899 to the Internet and are handling a general mix of mail. In such circumstances,
900 most messages can be delivered immediately. Consequently, Exim does not
901 maintain independent queues of messages for specific domains or hosts, though
902 it does try to send several messages in a single SMTP connection after a host
903 has been down, and it also maintains per-host retry information.
906 .section "Policy control" "SECID11"
907 .cindex "policy control" "overview"
908 Policy controls are now an important feature of MTAs that are connected to the
909 Internet. Perhaps their most important job is to stop MTAs being abused as
910 &"open relays"& by misguided individuals who send out vast amounts of
911 unsolicited junk, and want to disguise its source. Exim provides flexible
912 facilities for specifying policy controls on incoming mail:
914 .ilist
915 .cindex "&ACL;" "introduction"
916 Exim 4 (unlike previous versions of Exim) implements policy controls on
917 incoming mail by means of &'Access Control Lists'& (ACLs). Each list is a
918 series of statements that may either grant or deny access. ACLs can be used at
919 several places in the SMTP dialogue while receiving a message from a remote
920 host. However, the most common places are after each RCPT command, and at the
921 very end of the message. The sysadmin can specify conditions for accepting or
922 rejecting individual recipients or the entire message, respectively, at these
923 two points (see chapter &<<CHAPACL>>&). Denial of access results in an SMTP
924 error code.
925 .next
926 An ACL is also available for locally generated, non-SMTP messages. In this
927 case, the only available actions are to accept or deny the entire message.
928 .next
929 When Exim is compiled with the content-scanning extension, facilities are
930 provided in the ACL mechanism for passing the message to external virus and/or
931 spam scanning software. The result of such a scan is passed back to the ACL,
932 which can then use it to decide what to do with the message.
933 .next
934 When a message has been received, either from a remote host or from the local
935 host, but before the final acknowledgment has been sent, a locally supplied C
936 function called &[local_scan()]& can be run to inspect the message and decide
937 whether to accept it or not (see chapter &<<CHAPlocalscan>>&). If the message
938 is accepted, the list of recipients can be modified by the function.
939 .next
940 Using the &[local_scan()]& mechanism is another way of calling external scanner
941 software. The &%SA-Exim%& add-on package works this way. It does not require
942 Exim to be compiled with the content-scanning extension.
943 .next
944 After a message has been accepted, a further checking mechanism is available in
945 the form of the &'system filter'& (see chapter &<<CHAPsystemfilter>>&). This
946 runs at the start of every delivery process.
947 .endlist
951 .section "User filters" "SECID12"
952 .cindex "filter" "introduction"
953 .cindex "Sieve filter"
954 In a conventional Exim configuration, users are able to run private filters by
955 setting up appropriate &_.forward_& files in their home directories. See
956 chapter &<<CHAPredirect>>& (about the &(redirect)& router) for the
957 configuration needed to support this, and the separate document entitled
958 &'Exim's interfaces to mail filtering'& for user details. Two different kinds
959 of filtering are available:
961 .ilist
962 Sieve filters are written in the standard filtering language that is defined
963 by RFC 3028.
964 .next
965 Exim filters are written in a syntax that is unique to Exim, but which is more
966 powerful than Sieve, which it pre-dates.
967 .endlist
969 User filters are run as part of the routing process, described below.
973 .section "Message identification" "SECTmessiden"
974 .cindex "message ids" "details of format"
975 .cindex "format" "of message id"
976 .cindex "id of message"
977 .cindex "base62"
978 .cindex "base36"
979 .cindex "Darwin"
980 .cindex "Cygwin"
981 Every message handled by Exim is given a &'message id'& which is sixteen
982 characters long. It is divided into three parts, separated by hyphens, for
983 example &`16VDhn-0001bo-D3`&. Each part is a sequence of letters and digits,
984 normally encoding numbers in base 62. However, in the Darwin operating
985 system (Mac OS X) and when Exim is compiled to run under Cygwin, base 36
986 (avoiding the use of lower case letters) is used instead, because the message
987 id is used to construct file names, and the names of files in those systems are
988 not always case-sensitive.
990 .cindex "pid (process id)" "re-use of"
991 The detail of the contents of the message id have changed as Exim has evolved.
992 Earlier versions relied on the operating system not re-using a process id (pid)
993 within one second. On modern operating systems, this assumption can no longer
994 be made, so the algorithm had to be changed. To retain backward compatibility,
995 the format of the message id was retained, which is why the following rules are
996 somewhat eccentric:
998 .ilist
999 The first six characters of the message id are the time at which the message
1000 started to be received, to a granularity of one second. That is, this field
1001 contains the number of seconds since the start of the epoch (the normal Unix
1002 way of representing the date and time of day).
1003 .next
1004 After the first hyphen, the next six characters are the id of the process that
1005 received the message.
1006 .next
1007 There are two different possibilities for the final two characters:
1008 .olist
1009 .oindex "&%localhost_number%&"
1010 If &%localhost_number%& is not set, this value is the fractional part of the
1011 time of reception, normally in units of 1/2000 of a second, but for systems
1012 that must use base 36 instead of base 62 (because of case-insensitive file
1013 systems), the units are 1/1000 of a second.
1014 .next
1015 If &%localhost_number%& is set, it is multiplied by 200 (100) and added to
1016 the fractional part of the time, which in this case is in units of 1/200
1017 (1/100) of a second.
1018 .endlist
1019 .endlist
1021 After a message has been received, Exim waits for the clock to tick at the
1022 appropriate resolution before proceeding, so that if another message is
1023 received by the same process, or by another process with the same (re-used)
1024 pid, it is guaranteed that the time will be different. In most cases, the clock
1025 will already have ticked while the message was being received.
1028 .section "Receiving mail" "SECID13"
1029 .cindex "receiving mail"
1030 .cindex "message" "reception"
1031 The only way Exim can receive mail from another host is using SMTP over
1032 TCP/IP, in which case the sender and recipient addresses are transferred using
1033 SMTP commands. However, from a locally running process (such as a user's MUA),
1034 there are several possibilities:
1036 .ilist
1037 If the process runs Exim with the &%-bm%& option, the message is read
1038 non-interactively (usually via a pipe), with the recipients taken from the
1039 command line, or from the body of the message if &%-t%& is also used.
1040 .next
1041 If the process runs Exim with the &%-bS%& option, the message is also read
1042 non-interactively, but in this case the recipients are listed at the start of
1043 the message in a series of SMTP RCPT commands, terminated by a DATA
1044 command. This is so-called &"batch SMTP"& format,
1045 but it isn't really SMTP. The SMTP commands are just another way of passing
1046 envelope addresses in a non-interactive submission.
1047 .next
1048 If the process runs Exim with the &%-bs%& option, the message is read
1049 interactively, using the SMTP protocol. A two-way pipe is normally used for
1050 passing data between the local process and the Exim process.
1051 This is &"real"& SMTP and is handled in the same way as SMTP over TCP/IP. For
1052 example, the ACLs for SMTP commands are used for this form of submission.
1053 .next
1054 A local process may also make a TCP/IP call to the host's loopback address
1055 ( or any other of its IP addresses. When receiving messages, Exim
1056 does not treat the loopback address specially. It treats all such connections
1057 in the same way as connections from other hosts.
1058 .endlist
1061 .cindex "message sender, constructed by Exim"
1062 .cindex "sender" "constructed by Exim"
1063 In the three cases that do not involve TCP/IP, the sender address is
1064 constructed from the login name of the user that called Exim and a default
1065 qualification domain (which can be set by the &%qualify_domain%& configuration
1066 option). For local or batch SMTP, a sender address that is passed using the
1067 SMTP MAIL command is ignored. However, the system administrator may allow
1068 certain users (&"trusted users"&) to specify a different sender address
1069 unconditionally, or all users to specify certain forms of different sender
1070 address. The &%-f%& option or the SMTP MAIL command is used to specify these
1071 different addresses. See section &<<SECTtrustedadmin>>& for details of trusted
1072 users, and the &%untrusted_set_sender%& option for a way of allowing untrusted
1073 users to change sender addresses.
1075 Messages received by either of the non-interactive mechanisms are subject to
1076 checking by the non-SMTP ACL, if one is defined. Messages received using SMTP
1077 (either over TCP/IP, or interacting with a local process) can be checked by a
1078 number of ACLs that operate at different times during the SMTP session. Either
1079 individual recipients, or the entire message, can be rejected if local policy
1080 requirements are not met. The &[local_scan()]& function (see chapter
1081 &<<CHAPlocalscan>>&) is run for all incoming messages.
1083 Exim can be configured not to start a delivery process when a message is
1084 received; this can be unconditional, or depend on the number of incoming SMTP
1085 connections or the system load. In these situations, new messages wait on the
1086 queue until a queue runner process picks them up. However, in standard
1087 configurations under normal conditions, delivery is started as soon as a
1088 message is received.
1094 .section "Handling an incoming message" "SECID14"
1095 .cindex "spool directory" "files that hold a message"
1096 .cindex "file" "how a message is held"
1097 When Exim accepts a message, it writes two files in its spool directory. The
1098 first contains the envelope information, the current status of the message, and
1099 the header lines, and the second contains the body of the message. The names of
1100 the two spool files consist of the message id, followed by &`-H`& for the
1101 file containing the envelope and header, and &`-D`& for the data file.
1103 .cindex "spool directory" "&_input_& sub-directory"
1104 By default all these message files are held in a single directory called
1105 &_input_& inside the general Exim spool directory. Some operating systems do
1106 not perform very well if the number of files in a directory gets large; to
1107 improve performance in such cases, the &%split_spool_directory%& option can be
1108 used. This causes Exim to split up the input files into 62 sub-directories
1109 whose names are single letters or digits. When this is done, the queue is
1110 processed one sub-directory at a time instead of all at once, which can improve
1111 overall performance even when there are not enough files in each directory to
1112 affect file system performance.
1114 The envelope information consists of the address of the message's sender and
1115 the addresses of the recipients. This information is entirely separate from
1116 any addresses contained in the header lines. The status of the message includes
1117 a list of recipients who have already received the message. The format of the
1118 first spool file is described in chapter &<<CHAPspool>>&.
1120 .cindex "rewriting" "addresses"
1121 Address rewriting that is specified in the rewrite section of the configuration
1122 (see chapter &<<CHAPrewrite>>&) is done once and for all on incoming addresses,
1123 both in the header lines and the envelope, at the time the message is accepted.
1124 If during the course of delivery additional addresses are generated (for
1125 example, via aliasing), these new addresses are rewritten as soon as they are
1126 generated. At the time a message is actually delivered (transported) further
1127 rewriting can take place; because this is a transport option, it can be
1128 different for different forms of delivery. It is also possible to specify the
1129 addition or removal of certain header lines at the time the message is
1130 delivered (see chapters &<<CHAProutergeneric>>& and
1131 &<<CHAPtransportgeneric>>&).
1135 .section "Life of a message" "SECID15"
1136 .cindex "message" "life of"
1137 .cindex "message" "frozen"
1138 A message remains in the spool directory until it is completely delivered to
1139 its recipients or to an error address, or until it is deleted by an
1140 administrator or by the user who originally created it. In cases when delivery
1141 cannot proceed &-- for example, when a message can neither be delivered to its
1142 recipients nor returned to its sender, the message is marked &"frozen"& on the
1143 spool, and no more deliveries are attempted.
1145 .cindex "frozen messages" "thawing"
1146 .cindex "message" "thawing frozen"
1147 An administrator can &"thaw"& such messages when the problem has been
1148 corrected, and can also freeze individual messages by hand if necessary. In
1149 addition, an administrator can force a delivery error, causing a bounce message
1150 to be sent.
1152 .oindex "&%timeout_frozen_after%&"
1153 .oindex "&%ignore_bounce_errors_after%&"
1154 There are options called &%ignore_bounce_errors_after%& and
1155 &%timeout_frozen_after%&, which discard frozen messages after a certain time.
1156 The first applies only to frozen bounces, the second to any frozen messages.
1158 .cindex "message" "log file for"
1159 .cindex "log" "file for each message"
1160 While Exim is working on a message, it writes information about each delivery
1161 attempt to its main log file. This includes successful, unsuccessful, and
1162 delayed deliveries for each recipient (see chapter &<<CHAPlog>>&). The log
1163 lines are also written to a separate &'message log'& file for each message.
1164 These logs are solely for the benefit of the administrator, and are normally
1165 deleted along with the spool files when processing of a message is complete.
1166 The use of individual message logs can be disabled by setting
1167 &%no_message_logs%&; this might give an improvement in performance on very busy
1168 systems.
1170 .cindex "journal file"
1171 .cindex "file" "journal"
1172 All the information Exim itself needs to set up a delivery is kept in the first
1173 spool file, along with the header lines. When a successful delivery occurs, the
1174 address is immediately written at the end of a journal file, whose name is the
1175 message id followed by &`-J`&. At the end of a delivery run, if there are some
1176 addresses left to be tried again later, the first spool file (the &`-H`& file)
1177 is updated to indicate which these are, and the journal file is then deleted.
1178 Updating the spool file is done by writing a new file and renaming it, to
1179 minimize the possibility of data loss.
1181 Should the system or the program crash after a successful delivery but before
1182 the spool file has been updated, the journal is left lying around. The next
1183 time Exim attempts to deliver the message, it reads the journal file and
1184 updates the spool file before proceeding. This minimizes the chances of double
1185 deliveries caused by crashes.
1189 .section "Processing an address for delivery" "SECTprocaddress"
1190 .cindex "drivers" "definition of"
1191 .cindex "router" "definition of"
1192 .cindex "transport" "definition of"
1193 The main delivery processing elements of Exim are called &'routers'& and
1194 &'transports'&, and collectively these are known as &'drivers'&. Code for a
1195 number of them is provided in the source distribution, and compile-time options
1196 specify which ones are included in the binary. Run time options specify which
1197 ones are actually used for delivering messages.
1199 .cindex "drivers" "instance definition"
1200 Each driver that is specified in the run time configuration is an &'instance'&
1201 of that particular driver type. Multiple instances are allowed; for example,
1202 you can set up several different &(smtp)& transports, each with different
1203 option values that might specify different ports or different timeouts. Each
1204 instance has its own identifying name. In what follows we will normally use the
1205 instance name when discussing one particular instance (that is, one specific
1206 configuration of the driver), and the generic driver name when discussing
1207 the driver's features in general.
1209 A &'router'& is a driver that operates on an address, either determining how
1210 its delivery should happen, by assigning it to a specific transport, or
1211 converting the address into one or more new addresses (for example, via an
1212 alias file). A router may also explicitly choose to fail an address, causing it
1213 to be bounced.
1215 A &'transport'& is a driver that transmits a copy of the message from Exim's
1216 spool to some destination. There are two kinds of transport: for a &'local'&
1217 transport, the destination is a file or a pipe on the local host, whereas for a
1218 &'remote'& transport the destination is some other host. A message is passed
1219 to a specific transport as a result of successful routing. If a message has
1220 several recipients, it may be passed to a number of different transports.
1222 .cindex "preconditions" "definition of"
1223 An address is processed by passing it to each configured router instance in
1224 turn, subject to certain preconditions, until a router accepts the address or
1225 specifies that it should be bounced. We will describe this process in more
1226 detail shortly. First, as a simple example, we consider how each recipient
1227 address in a message is processed in a small configuration of three routers.
1229 To make this a more concrete example, it is described in terms of some actual
1230 routers, but remember, this is only an example. You can configure Exim's
1231 routers in many different ways, and there may be any number of routers in a
1232 configuration.
1234 The first router that is specified in a configuration is often one that handles
1235 addresses in domains that are not recognized specially by the local host. These
1236 are typically addresses for arbitrary domains on the Internet. A precondition
1237 is set up which looks for the special domains known to the host (for example,
1238 its own domain name), and the router is run for addresses that do &'not'&
1239 match. Typically, this is a router that looks up domains in the DNS in order to
1240 find the hosts to which this address routes. If it succeeds, the address is
1241 assigned to a suitable SMTP transport; if it does not succeed, the router is
1242 configured to fail the address.
1244 The second router is reached only when the domain is recognized as one that
1245 &"belongs"& to the local host. This router does redirection &-- also known as
1246 aliasing and forwarding. When it generates one or more new addresses from the
1247 original, each of them is routed independently from the start. Otherwise, the
1248 router may cause an address to fail, or it may simply decline to handle the
1249 address, in which case the address is passed to the next router.
1251 The final router in many configurations is one that checks to see if the
1252 address belongs to a local mailbox. The precondition may involve a check to
1253 see if the local part is the name of a login account, or it may look up the
1254 local part in a file or a database. If its preconditions are not met, or if
1255 the router declines, we have reached the end of the routers. When this happens,
1256 the address is bounced.
1260 .section "Processing an address for verification" "SECID16"
1261 .cindex "router" "for verification"
1262 .cindex "verifying address" "overview"
1263 As well as being used to decide how to deliver to an address, Exim's routers
1264 are also used for &'address verification'&. Verification can be requested as
1265 one of the checks to be performed in an ACL for incoming messages, on both
1266 sender and recipient addresses, and it can be tested using the &%-bv%& and
1267 &%-bvs%& command line options.
1269 When an address is being verified, the routers are run in &"verify mode"&. This
1270 does not affect the way the routers work, but it is a state that can be
1271 detected. By this means, a router can be skipped or made to behave differently
1272 when verifying. A common example is a configuration in which the first router
1273 sends all messages to a message-scanning program, unless they have been
1274 previously scanned. Thus, the first router accepts all addresses without any
1275 checking, making it useless for verifying. Normally, the &%no_verify%& option
1276 would be set for such a router, causing it to be skipped in verify mode.
1281 .section "Running an individual router" "SECTrunindrou"
1282 .cindex "router" "running details"
1283 .cindex "preconditions" "checking"
1284 .cindex "router" "result of running"
1285 As explained in the example above, a number of preconditions are checked before
1286 running a router. If any are not met, the router is skipped, and the address is
1287 passed to the next router. When all the preconditions on a router &'are'& met,
1288 the router is run. What happens next depends on the outcome, which is one of
1289 the following:
1291 .ilist
1292 &'accept'&: The router accepts the address, and either assigns it to a
1293 transport, or generates one or more &"child"& addresses. Processing the
1294 original address ceases,
1295 .oindex "&%unseen%&"
1296 unless the &%unseen%& option is set on the router. This option
1297 can be used to set up multiple deliveries with different routing (for example,
1298 for keeping archive copies of messages). When &%unseen%& is set, the address is
1299 passed to the next router. Normally, however, an &'accept'& return marks the
1300 end of routing.
1302 Any child addresses generated by the router are processed independently,
1303 starting with the first router by default. It is possible to change this by
1304 setting the &%redirect_router%& option to specify which router to start at for
1305 child addresses. Unlike &%pass_router%& (see below) the router specified by
1306 &%redirect_router%& may be anywhere in the router configuration.
1307 .next
1308 &'pass'&: The router recognizes the address, but cannot handle it itself. It
1309 requests that the address be passed to another router. By default the address
1310 is passed to the next router, but this can be changed by setting the
1311 &%pass_router%& option. However, (unlike &%redirect_router%&) the named router
1312 must be below the current router (to avoid loops).
1313 .next
1314 &'decline'&: The router declines to accept the address because it does not
1315 recognize it at all. By default, the address is passed to the next router, but
1316 this can be prevented by setting the &%no_more%& option. When &%no_more%& is
1317 set, all the remaining routers are skipped. In effect, &%no_more%& converts
1318 &'decline'& into &'fail'&.
1319 .next
1320 &'fail'&: The router determines that the address should fail, and queues it for
1321 the generation of a bounce message. There is no further processing of the
1322 original address unless &%unseen%& is set on the router.
1323 .next
1324 &'defer'&: The router cannot handle the address at the present time. (A
1325 database may be offline, or a DNS lookup may have timed out.) No further
1326 processing of the address happens in this delivery attempt. It is tried again
1327 next time the message is considered for delivery.
1328 .next
1329 &'error'&: There is some error in the router (for example, a syntax error in
1330 its configuration). The action is as for defer.
1331 .endlist
1333 If an address reaches the end of the routers without having been accepted by
1334 any of them, it is bounced as unrouteable. The default error message in this
1335 situation is &"unrouteable address"&, but you can set your own message by
1336 making use of the &%cannot_route_message%& option. This can be set for any
1337 router; the value from the last router that &"saw"& the address is used.
1339 Sometimes while routing you want to fail a delivery when some conditions are
1340 met but others are not, instead of passing the address on for further routing.
1341 You can do this by having a second router that explicitly fails the delivery
1342 when the relevant conditions are met. The &(redirect)& router has a &"fail"&
1343 facility for this purpose.
1346 .section "Duplicate addresses" "SECID17"
1347 .cindex "case of local parts"
1348 .cindex "address duplicate, discarding"
1349 .cindex "duplicate addresses"
1350 Once routing is complete, Exim scans the addresses that are assigned to local
1351 and remote transports, and discards any duplicates that it finds. During this
1352 check, local parts are treated as case-sensitive. This happens only when
1353 actually delivering a message; when testing routers with &%-bt%&, all the
1354 routed addresses are shown.
1358 .section "Router preconditions" "SECTrouprecon"
1359 .cindex "router" "preconditions, order of processing"
1360 .cindex "preconditions" "order of processing"
1361 The preconditions that are tested for each router are listed below, in the
1362 order in which they are tested. The individual configuration options are
1363 described in more detail in chapter &<<CHAProutergeneric>>&.
1365 .ilist
1366 The &%local_part_prefix%& and &%local_part_suffix%& options can specify that
1367 the local parts handled by the router may or must have certain prefixes and/or
1368 suffixes. If a mandatory affix (prefix or suffix) is not present, the router is
1369 skipped. These conditions are tested first. When an affix is present, it is
1370 removed from the local part before further processing, including the evaluation
1371 of any other conditions.
1372 .next
1373 Routers can be designated for use only when not verifying an address, that is,
1374 only when routing it for delivery (or testing its delivery routing). If the
1375 &%verify%& option is set false, the router is skipped when Exim is verifying an
1376 address.
1377 Setting the &%verify%& option actually sets two options, &%verify_sender%& and
1378 &%verify_recipient%&, which independently control the use of the router for
1379 sender and recipient verification. You can set these options directly if
1380 you want a router to be used for only one type of verification.
1381 Note that cutthrough delivery is classed as a recipient verification for this purpose.
1382 .next
1383 If the &%address_test%& option is set false, the router is skipped when Exim is
1384 run with the &%-bt%& option to test an address routing. This can be helpful
1385 when the first router sends all new messages to a scanner of some sort; it
1386 makes it possible to use &%-bt%& to test subsequent delivery routing without
1387 having to simulate the effect of the scanner.
1388 .next
1389 Routers can be designated for use only when verifying an address, as
1390 opposed to routing it for delivery. The &%verify_only%& option controls this.
1391 Again, cutthrough delivery counts as a verification.
1392 .next
1393 Individual routers can be explicitly skipped when running the routers to
1394 check an address given in the SMTP EXPN command (see the &%expn%& option).
1395 .next
1396 If the &%domains%& option is set, the domain of the address must be in the set
1397 of domains that it defines.
1398 .next
1399 .vindex "&$local_part_prefix$&"
1400 .vindex "&$local_part$&"
1401 .vindex "&$local_part_suffix$&"
1402 If the &%local_parts%& option is set, the local part of the address must be in
1403 the set of local parts that it defines. If &%local_part_prefix%& or
1404 &%local_part_suffix%& is in use, the prefix or suffix is removed from the local
1405 part before this check. If you want to do precondition tests on local parts
1406 that include affixes, you can do so by using a &%condition%& option (see below)
1407 that uses the variables &$local_part$&, &$local_part_prefix$&, and
1408 &$local_part_suffix$& as necessary.
1409 .next
1410 .vindex "&$local_user_uid$&"
1411 .vindex "&$local_user_gid$&"
1412 .vindex "&$home$&"
1413 If the &%check_local_user%& option is set, the local part must be the name of
1414 an account on the local host. If this check succeeds, the uid and gid of the
1415 local user are placed in &$local_user_uid$& and &$local_user_gid$& and the
1416 user's home directory is placed in &$home$&; these values can be used in the
1417 remaining preconditions.
1418 .next
1419 If the &%router_home_directory%& option is set, it is expanded at this point,
1420 because it overrides the value of &$home$&. If this expansion were left till
1421 later, the value of &$home$& as set by &%check_local_user%& would be used in
1422 subsequent tests. Having two different values of &$home$& in the same router
1423 could lead to confusion.
1424 .next
1425 If the &%senders%& option is set, the envelope sender address must be in the
1426 set of addresses that it defines.
1427 .next
1428 If the &%require_files%& option is set, the existence or non-existence of
1429 specified files is tested.
1430 .next
1431 .cindex "customizing" "precondition"
1432 If the &%condition%& option is set, it is evaluated and tested. This option
1433 uses an expanded string to allow you to set up your own custom preconditions.
1434 Expanded strings are described in chapter &<<CHAPexpand>>&.
1435 .endlist
1438 Note that &%require_files%& comes near the end of the list, so you cannot use
1439 it to check for the existence of a file in which to lookup up a domain, local
1440 part, or sender. However, as these options are all expanded, you can use the
1441 &%exists%& expansion condition to make such tests within each condition. The
1442 &%require_files%& option is intended for checking files that the router may be
1443 going to use internally, or which are needed by a specific transport (for
1444 example, &_.procmailrc_&).
1448 .section "Delivery in detail" "SECID18"
1449 .cindex "delivery" "in detail"
1450 When a message is to be delivered, the sequence of events is as follows:
1452 .ilist
1453 If a system-wide filter file is specified, the message is passed to it. The
1454 filter may add recipients to the message, replace the recipients, discard the
1455 message, cause a new message to be generated, or cause the message delivery to
1456 fail. The format of the system filter file is the same as for Exim user filter
1457 files, described in the separate document entitled &'Exim's interfaces to mail
1458 filtering'&.
1459 .cindex "Sieve filter" "not available for system filter"
1460 (&*Note*&: Sieve cannot be used for system filter files.)
1462 Some additional features are available in system filters &-- see chapter
1463 &<<CHAPsystemfilter>>& for details. Note that a message is passed to the system
1464 filter only once per delivery attempt, however many recipients it has. However,
1465 if there are several delivery attempts because one or more addresses could not
1466 be immediately delivered, the system filter is run each time. The filter
1467 condition &%first_delivery%& can be used to detect the first run of the system
1468 filter.
1469 .next
1470 Each recipient address is offered to each configured router in turn, subject to
1471 its preconditions, until one is able to handle it. If no router can handle the
1472 address, that is, if they all decline, the address is failed. Because routers
1473 can be targeted at particular domains, several locally handled domains can be
1474 processed entirely independently of each other.
1475 .next
1476 .cindex "routing" "loops in"
1477 .cindex "loop" "while routing"
1478 A router that accepts an address may assign it to a local or a remote
1479 transport. However, the transport is not run at this time. Instead, the address
1480 is placed on a list for the particular transport, which will be run later.
1481 Alternatively, the router may generate one or more new addresses (typically
1482 from alias, forward, or filter files). New addresses are fed back into this
1483 process from the top, but in order to avoid loops, a router ignores any address
1484 which has an identically-named ancestor that was processed by itself.
1485 .next
1486 When all the routing has been done, addresses that have been successfully
1487 handled are passed to their assigned transports. When local transports are
1488 doing real local deliveries, they handle only one address at a time, but if a
1489 local transport is being used as a pseudo-remote transport (for example, to
1490 collect batched SMTP messages for transmission by some other means) multiple
1491 addresses can be handled. Remote transports can always handle more than one
1492 address at a time, but can be configured not to do so, or to restrict multiple
1493 addresses to the same domain.
1494 .next
1495 Each local delivery to a file or a pipe runs in a separate process under a
1496 non-privileged uid, and these deliveries are run one at a time. Remote
1497 deliveries also run in separate processes, normally under a uid that is private
1498 to Exim (&"the Exim user"&), but in this case, several remote deliveries can be
1499 run in parallel. The maximum number of simultaneous remote deliveries for any
1500 one message is set by the &%remote_max_parallel%& option.
1501 The order in which deliveries are done is not defined, except that all local
1502 deliveries happen before any remote deliveries.
1503 .next
1504 .cindex "queue runner"
1505 When it encounters a local delivery during a queue run, Exim checks its retry
1506 database to see if there has been a previous temporary delivery failure for the
1507 address before running the local transport. If there was a previous failure,
1508 Exim does not attempt a new delivery until the retry time for the address is
1509 reached. However, this happens only for delivery attempts that are part of a
1510 queue run. Local deliveries are always attempted when delivery immediately
1511 follows message reception, even if retry times are set for them. This makes for
1512 better behaviour if one particular message is causing problems (for example,
1513 causing quota overflow, or provoking an error in a filter file).
1514 .next
1515 .cindex "delivery" "retry in remote transports"
1516 Remote transports do their own retry handling, since an address may be
1517 deliverable to one of a number of hosts, each of which may have a different
1518 retry time. If there have been previous temporary failures and no host has
1519 reached its retry time, no delivery is attempted, whether in a queue run or
1520 not. See chapter &<<CHAPretry>>& for details of retry strategies.
1521 .next
1522 If there were any permanent errors, a bounce message is returned to an
1523 appropriate address (the sender in the common case), with details of the error
1524 for each failing address. Exim can be configured to send copies of bounce
1525 messages to other addresses.
1526 .next
1527 .cindex "delivery" "deferral"
1528 If one or more addresses suffered a temporary failure, the message is left on
1529 the queue, to be tried again later. Delivery of these addresses is said to be
1530 &'deferred'&.
1531 .next
1532 When all the recipient addresses have either been delivered or bounced,
1533 handling of the message is complete. The spool files and message log are
1534 deleted, though the message log can optionally be preserved if required.
1535 .endlist
1540 .section "Retry mechanism" "SECID19"
1541 .cindex "delivery" "retry mechanism"
1542 .cindex "retry" "description of mechanism"
1543 .cindex "queue runner"
1544 Exim's mechanism for retrying messages that fail to get delivered at the first
1545 attempt is the queue runner process. You must either run an Exim daemon that
1546 uses the &%-q%& option with a time interval to start queue runners at regular
1547 intervals, or use some other means (such as &'cron'&) to start them. If you do
1548 not arrange for queue runners to be run, messages that fail temporarily at the
1549 first attempt will remain on your queue for ever. A queue runner process works
1550 its way through the queue, one message at a time, trying each delivery that has
1551 passed its retry time.
1552 You can run several queue runners at once.
1554 Exim uses a set of configured rules to determine when next to retry the failing
1555 address (see chapter &<<CHAPretry>>&). These rules also specify when Exim
1556 should give up trying to deliver to the address, at which point it generates a
1557 bounce message. If no retry rules are set for a particular host, address, and
1558 error combination, no retries are attempted, and temporary errors are treated
1559 as permanent.
1563 .section "Temporary delivery failure" "SECID20"
1564 .cindex "delivery" "temporary failure"
1565 There are many reasons why a message may not be immediately deliverable to a
1566 particular address. Failure to connect to a remote machine (because it, or the
1567 connection to it, is down) is one of the most common. Temporary failures may be
1568 detected during routing as well as during the transport stage of delivery.
1569 Local deliveries may be delayed if NFS files are unavailable, or if a mailbox
1570 is on a file system where the user is over quota. Exim can be configured to
1571 impose its own quotas on local mailboxes; where system quotas are set they will
1572 also apply.
1574 If a host is unreachable for a period of time, a number of messages may be
1575 waiting for it by the time it recovers, and sending them in a single SMTP
1576 connection is clearly beneficial. Whenever a delivery to a remote host is
1577 deferred,
1578 .cindex "hints database"
1579 Exim makes a note in its hints database, and whenever a successful
1580 SMTP delivery has happened, it looks to see if any other messages are waiting
1581 for the same host. If any are found, they are sent over the same SMTP
1582 connection, subject to a configuration limit as to the maximum number in any
1583 one connection.
1587 .section "Permanent delivery failure" "SECID21"
1588 .cindex "delivery" "permanent failure"
1589 .cindex "bounce message" "when generated"
1590 When a message cannot be delivered to some or all of its intended recipients, a
1591 bounce message is generated. Temporary delivery failures turn into permanent
1592 errors when their timeout expires. All the addresses that fail in a given
1593 delivery attempt are listed in a single message. If the original message has
1594 many recipients, it is possible for some addresses to fail in one delivery
1595 attempt and others to fail subsequently, giving rise to more than one bounce
1596 message. The wording of bounce messages can be customized by the administrator.
1597 See chapter &<<CHAPemsgcust>>& for details.
1599 .cindex "&'X-Failed-Recipients:'& header line"
1600 Bounce messages contain an &'X-Failed-Recipients:'& header line that lists the
1601 failed addresses, for the benefit of programs that try to analyse such messages
1602 automatically.
1604 .cindex "bounce message" "recipient of"
1605 A bounce message is normally sent to the sender of the original message, as
1606 obtained from the message's envelope. For incoming SMTP messages, this is the
1607 address given in the MAIL command. However, when an address is expanded via a
1608 forward or alias file, an alternative address can be specified for delivery
1609 failures of the generated addresses. For a mailing list expansion (see section
1610 &<<SECTmailinglists>>&) it is common to direct bounce messages to the manager
1611 of the list.
1615 .section "Failures to deliver bounce messages" "SECID22"
1616 .cindex "bounce message" "failure to deliver"
1617 If a bounce message (either locally generated or received from a remote host)
1618 itself suffers a permanent delivery failure, the message is left on the queue,
1619 but it is frozen, awaiting the attention of an administrator. There are options
1620 that can be used to make Exim discard such failed messages, or to keep them
1621 for only a short time (see &%timeout_frozen_after%& and
1622 &%ignore_bounce_errors_after%&).
1628 . ////////////////////////////////////////////////////////////////////////////
1629 . ////////////////////////////////////////////////////////////////////////////
1631 .chapter "Building and installing Exim" "CHID3"
1632 .scindex IIDbuex "building Exim"
1634 .section "Unpacking" "SECID23"
1635 Exim is distributed as a gzipped or bzipped tar file which, when unpacked,
1636 creates a directory with the name of the current release (for example,
1637 &_exim-&version()_&) into which the following files are placed:
1639 .table2 140pt
1640 .irow &_ACKNOWLEDGMENTS_& "contains some acknowledgments"
1641 .irow &_CHANGES_& "contains a reference to where changes are &&&
1642 documented"
1643 .irow &_LICENCE_& "the GNU General Public Licence"
1644 .irow &_Makefile_& "top-level make file"
1645 .irow &_NOTICE_& "conditions for the use of Exim"
1646 .irow &_README_& "list of files, directories and simple build &&&
1647 instructions"
1648 .endtable
1650 Other files whose names begin with &_README_& may also be present. The
1651 following subdirectories are created:
1653 .table2 140pt
1654 .irow &_Local_& "an empty directory for local configuration files"
1655 .irow &_OS_& "OS-specific files"
1656 .irow &_doc_& "documentation files"
1657 .irow &_exim_monitor_& "source files for the Exim monitor"
1658 .irow &_scripts_& "scripts used in the build process"
1659 .irow &_src_& "remaining source files"
1660 .irow &_util_& "independent utilities"
1661 .endtable
1663 The main utility programs are contained in the &_src_& directory, and are built
1664 with the Exim binary. The &_util_& directory contains a few optional scripts
1665 that may be useful to some sites.
1668 .section "Multiple machine architectures and operating systems" "SECID24"
1669 .cindex "building Exim" "multiple OS/architectures"
1670 The building process for Exim is arranged to make it easy to build binaries for
1671 a number of different architectures and operating systems from the same set of
1672 source files. Compilation does not take place in the &_src_& directory.
1673 Instead, a &'build directory'& is created for each architecture and operating
1674 system.
1675 .cindex "symbolic link" "to build directory"
1676 Symbolic links to the sources are installed in this directory, which is where
1677 the actual building takes place. In most cases, Exim can discover the machine
1678 architecture and operating system for itself, but the defaults can be
1679 overridden if necessary.
1682 .section "PCRE library" "SECTpcre"
1683 .cindex "PCRE library"
1684 Exim no longer has an embedded PCRE library as the vast majority of
1685 modern systems include PCRE as a system library, although you may need
1686 to install the PCRE or PCRE development package for your operating
1687 system. If your system has a normal PCRE installation the Exim build
1688 process will need no further configuration. If the library or the
1689 headers are in an unusual location you will need to either set the PCRE_LIBS
1690 and INCLUDE directives appropriately,
1691 or set PCRE_CONFIG=yes to use the installed &(pcre-config)& command.
1692 If your operating system has no
1693 PCRE support then you will need to obtain and build the current PCRE
1694 from &url(
1695 More information on PCRE is available at &url(
1697 .section "DBM libraries" "SECTdb"
1698 .cindex "DBM libraries" "discussion of"
1699 .cindex "hints database" "DBM files used for"
1700 Even if you do not use any DBM files in your configuration, Exim still needs a
1701 DBM library in order to operate, because it uses indexed files for its hints
1702 databases. Unfortunately, there are a number of DBM libraries in existence, and
1703 different operating systems often have different ones installed.
1705 .cindex "Solaris" "DBM library for"
1706 .cindex "IRIX, DBM library for"
1707 .cindex "BSD, DBM library for"
1708 .cindex "Linux, DBM library for"
1709 If you are using Solaris, IRIX, one of the modern BSD systems, or a modern
1710 Linux distribution, the DBM configuration should happen automatically, and you
1711 may be able to ignore this section. Otherwise, you may have to learn more than
1712 you would like about DBM libraries from what follows.
1714 .cindex "&'ndbm'& DBM library"
1715 Licensed versions of Unix normally contain a library of DBM functions operating
1716 via the &'ndbm'& interface, and this is what Exim expects by default. Free
1717 versions of Unix seem to vary in what they contain as standard. In particular,
1718 some early versions of Linux have no default DBM library, and different
1719 distributors have chosen to bundle different libraries with their packaged
1720 versions. However, the more recent releases seem to have standardized on the
1721 Berkeley DB library.
1723 Different DBM libraries have different conventions for naming the files they
1724 use. When a program opens a file called &_dbmfile_&, there are several
1725 possibilities:
1727 .olist
1728 A traditional &'ndbm'& implementation, such as that supplied as part of
1729 Solaris, operates on two files called &_dbmfile.dir_& and &_dbmfile.pag_&.
1730 .next
1731 .cindex "&'gdbm'& DBM library"
1732 The GNU library, &'gdbm'&, operates on a single file. If used via its &'ndbm'&
1733 compatibility interface it makes two different hard links to it with names
1734 &_dbmfile.dir_& and &_dbmfile.pag_&, but if used via its native interface, the
1735 file name is used unmodified.
1736 .next
1737 .cindex "Berkeley DB library"
1738 The Berkeley DB package, if called via its &'ndbm'& compatibility interface,
1739 operates on a single file called &_dbmfile.db_&, but otherwise looks to the
1740 programmer exactly the same as the traditional &'ndbm'& implementation.
1741 .next
1742 If the Berkeley package is used in its native mode, it operates on a single
1743 file called &_dbmfile_&; the programmer's interface is somewhat different to
1744 the traditional &'ndbm'& interface.
1745 .next
1746 To complicate things further, there are several very different versions of the
1747 Berkeley DB package. Version 1.85 was stable for a very long time, releases
1748 2.&'x'& and 3.&'x'& were current for a while, but the latest versions are now
1749 numbered 4.&'x'&. Maintenance of some of the earlier releases has ceased. All
1750 versions of Berkeley DB can be obtained from
1751 &url(
1752 .next
1753 .cindex "&'tdb'& DBM library"
1754 Yet another DBM library, called &'tdb'&, is available from
1755 &url( It has its own interface, and also
1756 operates on a single file.
1757 .endlist
1759 .cindex "USE_DB"
1760 .cindex "DBM libraries" "configuration for building"
1761 Exim and its utilities can be compiled to use any of these interfaces. In order
1762 to use any version of the Berkeley DB package in native mode, you must set
1763 USE_DB in an appropriate configuration file (typically
1764 &_Local/Makefile_&). For example:
1765 .code
1766 USE_DB=yes
1767 .endd
1768 Similarly, for gdbm you set USE_GDBM, and for tdb you set USE_TDB. An
1769 error is diagnosed if you set more than one of these.
1771 At the lowest level, the build-time configuration sets none of these options,
1772 thereby assuming an interface of type (1). However, some operating system
1773 configuration files (for example, those for the BSD operating systems and
1774 Linux) assume type (4) by setting USE_DB as their default, and the
1775 configuration files for Cygwin set USE_GDBM. Anything you set in
1776 &_Local/Makefile_&, however, overrides these system defaults.
1778 As well as setting USE_DB, USE_GDBM, or USE_TDB, it may also be
1779 necessary to set DBMLIB, to cause inclusion of the appropriate library, as
1780 in one of these lines:
1781 .code
1782 DBMLIB = -ldb
1783 DBMLIB = -ltdb
1784 .endd
1785 Settings like that will work if the DBM library is installed in the standard
1786 place. Sometimes it is not, and the library's header file may also not be in
1787 the default path. You may need to set INCLUDE to specify where the header
1788 file is, and to specify the path to the library more fully in DBMLIB, as in
1789 this example:
1790 .code
1791 INCLUDE=-I/usr/local/include/db-4.1
1792 DBMLIB=/usr/local/lib/db-4.1/libdb.a
1793 .endd
1794 There is further detailed discussion about the various DBM libraries in the
1795 file &_doc/dbm.discuss.txt_& in the Exim distribution.
1799 .section "Pre-building configuration" "SECID25"
1800 .cindex "building Exim" "pre-building configuration"
1801 .cindex "configuration for building Exim"
1802 .cindex "&_Local/Makefile_&"
1803 .cindex "&_src/EDITME_&"
1804 Before building Exim, a local configuration file that specifies options
1805 independent of any operating system has to be created with the name
1806 &_Local/Makefile_&. A template for this file is supplied as the file
1807 &_src/EDITME_&, and it contains full descriptions of all the option settings
1808 therein. These descriptions are therefore not repeated here. If you are
1809 building Exim for the first time, the simplest thing to do is to copy
1810 &_src/EDITME_& to &_Local/Makefile_&, then read it and edit it appropriately.
1812 There are three settings that you must supply, because Exim will not build
1813 without them. They are the location of the run time configuration file
1814 (CONFIGURE_FILE), the directory in which Exim binaries will be installed
1815 (BIN_DIRECTORY), and the identity of the Exim user (EXIM_USER and
1816 maybe EXIM_GROUP as well). The value of CONFIGURE_FILE can in fact be
1817 a colon-separated list of file names; Exim uses the first of them that exists.
1819 There are a few other parameters that can be specified either at build time or
1820 at run time, to enable the same binary to be used on a number of different
1821 machines. However, if the locations of Exim's spool directory and log file
1822 directory (if not within the spool directory) are fixed, it is recommended that
1823 you specify them in &_Local/Makefile_& instead of at run time, so that errors
1824 detected early in Exim's execution (such as a malformed configuration file) can
1825 be logged.
1827 .cindex "content scanning" "specifying at build time"
1828 Exim's interfaces for calling virus and spam scanning software directly from
1829 access control lists are not compiled by default. If you want to include these
1830 facilities, you need to set
1831 .code
1833 .endd
1834 in your &_Local/Makefile_&. For details of the facilities themselves, see
1835 chapter &<<CHAPexiscan>>&.
1838 .cindex "&_Local/eximon.conf_&"
1839 .cindex "&_exim_monitor/EDITME_&"
1840 If you are going to build the Exim monitor, a similar configuration process is
1841 required. The file &_exim_monitor/EDITME_& must be edited appropriately for
1842 your installation and saved under the name &_Local/eximon.conf_&. If you are
1843 happy with the default settings described in &_exim_monitor/EDITME_&,
1844 &_Local/eximon.conf_& can be empty, but it must exist.
1846 This is all the configuration that is needed in straightforward cases for known
1847 operating systems. However, the building process is set up so that it is easy
1848 to override options that are set by default or by operating-system-specific
1849 configuration files, for example to change the name of the C compiler, which
1850 defaults to &%gcc%&. See section &<<SECToverride>>& below for details of how to
1851 do this.
1855 .section "Support for iconv()" "SECID26"
1856 .cindex "&[iconv()]& support"
1857 .cindex "RFC 2047"
1858 The contents of header lines in messages may be encoded according to the rules
1859 described RFC 2047. This makes it possible to transmit characters that are not
1860 in the ASCII character set, and to label them as being in a particular
1861 character set. When Exim is inspecting header lines by means of the &%$h_%&
1862 mechanism, it decodes them, and translates them into a specified character set
1863 (default ISO-8859-1). The translation is possible only if the operating system
1864 supports the &[iconv()]& function.
1866 However, some of the operating systems that supply &[iconv()]& do not support
1867 very many conversions. The GNU &%libiconv%& library (available from
1868 &url( can be installed on such
1869 systems to remedy this deficiency, as well as on systems that do not supply
1870 &[iconv()]& at all. After installing &%libiconv%&, you should add
1871 .code
1872 HAVE_ICONV=yes
1873 .endd
1874 to your &_Local/Makefile_& and rebuild Exim.
1878 .section "Including TLS/SSL encryption support" "SECTinctlsssl"
1879 .cindex "TLS" "including support for TLS"
1880 .cindex "encryption" "including support for"
1881 .cindex "SUPPORT_TLS"
1882 .cindex "OpenSSL" "building Exim with"
1883 .cindex "GnuTLS" "building Exim with"
1884 Exim can be built to support encrypted SMTP connections, using the STARTTLS
1885 command as per RFC 2487. It can also support legacy clients that expect to
1886 start a TLS session immediately on connection to a non-standard port (see the
1887 &%tls_on_connect_ports%& runtime option and the &%-tls-on-connect%& command
1888 line option).
1890 If you want to build Exim with TLS support, you must first install either the
1891 OpenSSL or GnuTLS library. There is no cryptographic code in Exim itself for
1892 implementing SSL.
1894 If OpenSSL is installed, you should set
1895 .code
1896 SUPPORT_TLS=yes
1897 TLS_LIBS=-lssl -lcrypto
1898 .endd
1899 in &_Local/Makefile_&. You may also need to specify the locations of the
1900 OpenSSL library and include files. For example:
1901 .code
1902 SUPPORT_TLS=yes
1903 TLS_LIBS=-L/usr/local/openssl/lib -lssl -lcrypto
1904 TLS_INCLUDE=-I/usr/local/openssl/include/
1905 .endd
1906 .cindex "pkg-config" "OpenSSL"
1907 If you have &'pkg-config'& available, then instead you can just use:
1908 .code
1909 SUPPORT_TLS=yes
1910 USE_OPENSSL_PC=openssl
1911 .endd
1912 .cindex "USE_GNUTLS"
1913 If GnuTLS is installed, you should set
1914 .code
1915 SUPPORT_TLS=yes
1916 USE_GNUTLS=yes
1917 TLS_LIBS=-lgnutls -ltasn1 -lgcrypt
1918 .endd
1919 in &_Local/Makefile_&, and again you may need to specify the locations of the
1920 library and include files. For example:
1921 .code
1922 SUPPORT_TLS=yes
1923 USE_GNUTLS=yes
1924 TLS_LIBS=-L/usr/gnu/lib -lgnutls -ltasn1 -lgcrypt
1925 TLS_INCLUDE=-I/usr/gnu/include
1926 .endd
1927 .cindex "pkg-config" "GnuTLS"
1928 If you have &'pkg-config'& available, then instead you can just use:
1929 .code
1930 SUPPORT_TLS=yes
1931 USE_GNUTLS=yes
1932 USE_GNUTLS_PC=gnutls
1933 .endd
1935 You do not need to set TLS_INCLUDE if the relevant directory is already
1936 specified in INCLUDE. Details of how to configure Exim to make use of TLS are
1937 given in chapter &<<CHAPTLS>>&.
1942 .section "Use of tcpwrappers" "SECID27"
1944 .cindex "tcpwrappers, building Exim to support"
1945 .cindex "USE_TCP_WRAPPERS"
1947 .cindex "tcp_wrappers_daemon_name"
1948 Exim can be linked with the &'tcpwrappers'& library in order to check incoming
1949 SMTP calls using the &'tcpwrappers'& control files. This may be a convenient
1950 alternative to Exim's own checking facilities for installations that are
1951 already making use of &'tcpwrappers'& for other purposes. To do this, you
1952 should set USE_TCP_WRAPPERS in &_Local/Makefile_&, arrange for the file
1953 &_tcpd.h_& to be available at compile time, and also ensure that the library
1954 &_libwrap.a_& is available at link time, typically by including &%-lwrap%& in
1955 EXTRALIBS_EXIM. For example, if &'tcpwrappers'& is installed in &_/usr/local_&,
1956 you might have
1957 .code
1959 CFLAGS=-O -I/usr/local/include
1960 EXTRALIBS_EXIM=-L/usr/local/lib -lwrap
1961 .endd
1962 in &_Local/Makefile_&. The daemon name to use in the &'tcpwrappers'& control
1963 files is &"exim"&. For example, the line
1964 .code
1965 exim : LOCAL 192.168.1. .friendly.domain.example
1966 .endd
1967 in your &_/etc/hosts.allow_& file allows connections from the local host, from
1968 the subnet, and from all hosts in &'friendly.domain.example'&.
1969 All other connections are denied. The daemon name used by &'tcpwrappers'&
1970 can be changed at build time by setting TCP_WRAPPERS_DAEMON_NAME in
1971 &_Local/Makefile_&, or by setting tcp_wrappers_daemon_name in the
1972 configure file. Consult the &'tcpwrappers'& documentation for
1973 further details.
1976 .section "Including support for IPv6" "SECID28"
1977 .cindex "IPv6" "including support for"
1978 Exim contains code for use on systems that have IPv6 support. Setting
1979 &`HAVE_IPV6=YES`& in &_Local/Makefile_& causes the IPv6 code to be included;
1980 it may also be necessary to set IPV6_INCLUDE and IPV6_LIBS on systems
1981 where the IPv6 support is not fully integrated into the normal include and
1982 library files.
1984 Two different types of DNS record for handling IPv6 addresses have been
1985 defined. AAAA records (analogous to A records for IPv4) are in use, and are
1986 currently seen as the mainstream. Another record type called A6 was proposed
1987 as better than AAAA because it had more flexibility. However, it was felt to be
1988 over-complex, and its status was reduced to &"experimental"&.
1989 .new
1990 Exim used to
1991 have a compile option for including A6 record support but this has now been
1992 withdrawn.
1993 .wen
1997 .section "Dynamically loaded lookup module support" "SECTdynamicmodules"
1998 .cindex "lookup modules"
1999 .cindex "dynamic modules"
2000 .cindex ".so building"
2001 On some platforms, Exim supports not compiling all lookup types directly into
2002 the main binary, instead putting some into external modules which can be loaded
2003 on demand.
2004 This permits packagers to build Exim with support for lookups with extensive
2005 library dependencies without requiring all users to install all of those
2006 dependencies.
2007 Most, but not all, lookup types can be built this way.
2009 Set &`LOOKUP_MODULE_DIR`& to the directory into which the modules will be
2010 installed; Exim will only load modules from that directory, as a security
2011 measure. You will need to set &`CFLAGS_DYNAMIC`& if not already defined
2012 for your OS; see &_OS/Makefile-Linux_& for an example.
2013 Some other requirements for adjusting &`EXTRALIBS`& may also be necessary,
2014 see &_src/EDITME_& for details.
2016 Then, for each module to be loaded dynamically, define the relevant
2017 &`LOOKUP_`&<&'lookup_type'&> flags to have the value "2" instead of "yes".
2018 For example, this will build in lsearch but load sqlite and mysql support
2019 on demand:
2020 .code
2024 .endd
2027 .section "The building process" "SECID29"
2028 .cindex "build directory"
2029 Once &_Local/Makefile_& (and &_Local/eximon.conf_&, if required) have been
2030 created, run &'make'& at the top level. It determines the architecture and
2031 operating system types, and creates a build directory if one does not exist.
2032 For example, on a Sun system running Solaris 8, the directory
2033 &_build-SunOS5-5.8-sparc_& is created.
2034 .cindex "symbolic link" "to source files"
2035 Symbolic links to relevant source files are installed in the build directory.
2037 &*Warning*&: The &%-j%& (parallel) flag must not be used with &'make'&; the
2038 building process fails if it is set.
2040 If this is the first time &'make'& has been run, it calls a script that builds
2041 a make file inside the build directory, using the configuration files from the
2042 &_Local_& directory. The new make file is then passed to another instance of
2043 &'make'&. This does the real work, building a number of utility scripts, and
2044 then compiling and linking the binaries for the Exim monitor (if configured), a
2045 number of utility programs, and finally Exim itself. The command &`make
2046 makefile`& can be used to force a rebuild of the make file in the build
2047 directory, should this ever be necessary.
2049 If you have problems building Exim, check for any comments there may be in the
2050 &_README_& file concerning your operating system, and also take a look at the
2051 FAQ, where some common problems are covered.
2055 .section 'Output from &"make"&' "SECID283"
2056 The output produced by the &'make'& process for compile lines is often very
2057 unreadable, because these lines can be very long. For this reason, the normal
2058 output is suppressed by default, and instead output similar to that which
2059 appears when compiling the 2.6 Linux kernel is generated: just a short line for
2060 each module that is being compiled or linked. However, it is still possible to
2061 get the full output, by calling &'make'& like this:
2062 .code
2063 FULLECHO='' make -e
2064 .endd
2065 The value of FULLECHO defaults to &"@"&, the flag character that suppresses
2066 command reflection in &'make'&. When you ask for the full output, it is
2067 given in addition to the short output.
2071 .section "Overriding build-time options for Exim" "SECToverride"
2072 .cindex "build-time options, overriding"
2073 The main make file that is created at the beginning of the building process
2074 consists of the concatenation of a number of files which set configuration
2075 values, followed by a fixed set of &'make'& instructions. If a value is set
2076 more than once, the last setting overrides any previous ones. This provides a
2077 convenient way of overriding defaults. The files that are concatenated are, in
2078 order:
2079 .display
2080 &_OS/Makefile-Default_&
2081 &_OS/Makefile-_&<&'ostype'&>
2082 &_Local/Makefile_&
2083 &_Local/Makefile-_&<&'ostype'&>
2084 &_Local/Makefile-_&<&'archtype'&>
2085 &_Local/Makefile-_&<&'ostype'&>-<&'archtype'&>
2086 &_OS/Makefile-Base_&
2087 .endd
2088 .cindex "&_Local/Makefile_&"
2089 .cindex "building Exim" "operating system type"
2090 .cindex "building Exim" "architecture type"
2091 where <&'ostype'&> is the operating system type and <&'archtype'&> is the
2092 architecture type. &_Local/Makefile_& is required to exist, and the building
2093 process fails if it is absent. The other three &_Local_& files are optional,
2094 and are often not needed.
2096 The values used for <&'ostype'&> and <&'archtype'&> are obtained from scripts
2097 called &_scripts/os-type_& and &_scripts/arch-type_& respectively. If either of
2098 the environment variables EXIM_OSTYPE or EXIM_ARCHTYPE is set, their
2099 values are used, thereby providing a means of forcing particular settings.
2100 Otherwise, the scripts try to get values from the &%uname%& command. If this
2101 fails, the shell variables OSTYPE and ARCHTYPE are inspected. A number
2102 of &'ad hoc'& transformations are then applied, to produce the standard names
2103 that Exim expects. You can run these scripts directly from the shell in order
2104 to find out what values are being used on your system.
2107 &_OS/Makefile-Default_& contains comments about the variables that are set
2108 therein. Some (but not all) are mentioned below. If there is something that
2109 needs changing, review the contents of this file and the contents of the make
2110 file for your operating system (&_OS/Makefile-<ostype>_&) to see what the
2111 default values are.
2114 .cindex "building Exim" "overriding default settings"
2115 If you need to change any of the values that are set in &_OS/Makefile-Default_&
2116 or in &_OS/Makefile-<ostype>_&, or to add any new definitions, you do not
2117 need to change the original files. Instead, you should make the changes by
2118 putting the new values in an appropriate &_Local_& file. For example,
2119 .cindex "Tru64-Unix build-time settings"
2120 when building Exim in many releases of the Tru64-Unix (formerly Digital UNIX,
2121 formerly DEC-OSF1) operating system, it is necessary to specify that the C
2122 compiler is called &'cc'& rather than &'gcc'&. Also, the compiler must be
2123 called with the option &%-std1%&, to make it recognize some of the features of
2124 Standard C that Exim uses. (Most other compilers recognize Standard C by
2125 default.) To do this, you should create a file called &_Local/Makefile-OSF1_&
2126 containing the lines
2127 .code
2128 CC=cc
2129 CFLAGS=-std1
2130 .endd
2131 If you are compiling for just one operating system, it may be easier to put
2132 these lines directly into &_Local/Makefile_&.
2134 Keeping all your local configuration settings separate from the distributed
2135 files makes it easy to transfer them to new versions of Exim simply by copying
2136 the contents of the &_Local_& directory.
2139 .cindex "NIS lookup type" "including support for"
2140 .cindex "NIS+ lookup type" "including support for"
2141 .cindex "LDAP" "including support for"
2142 .cindex "lookup" "inclusion in binary"
2143 Exim contains support for doing LDAP, NIS, NIS+, and other kinds of file
2144 lookup, but not all systems have these components installed, so the default is
2145 not to include the relevant code in the binary. All the different kinds of file
2146 and database lookup that Exim supports are implemented as separate code modules
2147 which are included only if the relevant compile-time options are set. In the
2148 case of LDAP, NIS, and NIS+, the settings for &_Local/Makefile_& are:
2149 .code
2150 LOOKUP_LDAP=yes
2151 LOOKUP_NIS=yes
2153 .endd
2154 and similar settings apply to the other lookup types. They are all listed in
2155 &_src/EDITME_&. In many cases the relevant include files and interface
2156 libraries need to be installed before compiling Exim.
2157 .cindex "cdb" "including support for"
2158 However, there are some optional lookup types (such as cdb) for which
2159 the code is entirely contained within Exim, and no external include
2160 files or libraries are required. When a lookup type is not included in the
2161 binary, attempts to configure Exim to use it cause run time configuration
2162 errors.
2164 .cindex "pkg-config" "lookups"
2165 .cindex "pkg-config" "authenticators"
2166 Many systems now use a tool called &'pkg-config'& to encapsulate information
2167 about how to compile against a library; Exim has some initial support for
2168 being able to use pkg-config for lookups and authenticators. For any given
2169 makefile variable which starts &`LOOKUP_`& or &`AUTH_`&, you can add a new
2170 variable with the &`_PC`& suffix in the name and assign as the value the
2171 name of the package to be queried. The results of querying via the
2172 &'pkg-config'& command will be added to the appropriate Makefile variables
2173 with &`+=`& directives, so your version of &'make'& will need to support that
2174 syntax. For instance:
2175 .code
2177 LOOKUP_SQLITE_PC=sqlite3
2178 AUTH_GSASL=yes
2179 AUTH_GSASL_PC=libgsasl
2181 AUTH_HEIMDAL_GSSAPI_PC=heimdal-gssapi
2182 .endd
2184 .cindex "Perl" "including support for"
2185 Exim can be linked with an embedded Perl interpreter, allowing Perl
2186 subroutines to be called during string expansion. To enable this facility,
2187 .code
2188 EXIM_PERL=perl.o
2189 .endd
2190 must be defined in &_Local/Makefile_&. Details of this facility are given in
2191 chapter &<<CHAPperl>>&.
2193 .cindex "X11 libraries, location of"
2194 The location of the X11 libraries is something that varies a lot between
2195 operating systems, and there may be different versions of X11 to cope
2196 with. Exim itself makes no use of X11, but if you are compiling the Exim
2197 monitor, the X11 libraries must be available.
2198 The following three variables are set in &_OS/Makefile-Default_&:
2199 .code
2200 X11=/usr/X11R6
2201 XINCLUDE=-I$(X11)/include
2202 XLFLAGS=-L$(X11)/lib
2203 .endd
2204 These are overridden in some of the operating-system configuration files. For
2205 example, in &_OS/Makefile-SunOS5_& there is
2206 .code
2207 X11=/usr/openwin
2208 XINCLUDE=-I$(X11)/include
2209 XLFLAGS=-L$(X11)/lib -R$(X11)/lib
2210 .endd
2211 If you need to override the default setting for your operating system, place a
2212 definition of all three of these variables into your
2213 &_Local/Makefile-<ostype>_& file.
2215 .cindex "EXTRALIBS"
2216 If you need to add any extra libraries to the link steps, these can be put in a
2217 variable called EXTRALIBS, which appears in all the link commands, but by
2218 default is not defined. In contrast, EXTRALIBS_EXIM is used only on the
2219 command for linking the main Exim binary, and not for any associated utilities.
2221 .cindex "DBM libraries" "configuration for building"
2222 There is also DBMLIB, which appears in the link commands for binaries that
2223 use DBM functions (see also section &<<SECTdb>>&). Finally, there is
2224 EXTRALIBS_EXIMON, which appears only in the link step for the Exim monitor
2225 binary, and which can be used, for example, to include additional X11
2226 libraries.
2228 .cindex "configuration file" "editing"
2229 The make file copes with rebuilding Exim correctly if any of the configuration
2230 files are edited. However, if an optional configuration file is deleted, it is
2231 necessary to touch the associated non-optional file (that is,
2232 &_Local/Makefile_& or &_Local/eximon.conf_&) before rebuilding.
2235 .section "OS-specific header files" "SECID30"
2236 .cindex "&_os.h_&"
2237 .cindex "building Exim" "OS-specific C header files"
2238 The &_OS_& directory contains a number of files with names of the form
2239 &_os.h-<ostype>_&. These are system-specific C header files that should not
2240 normally need to be changed. There is a list of macro settings that are
2241 recognized in the file &_OS/os.configuring_&, which should be consulted if you
2242 are porting Exim to a new operating system.
2246 .section "Overriding build-time options for the monitor" "SECID31"
2247 .cindex "building Eximon"
2248 A similar process is used for overriding things when building the Exim monitor,
2249 where the files that are involved are
2250 .display
2251 &_OS/eximon.conf-Default_&
2252 &_OS/eximon.conf-_&<&'ostype'&>
2253 &_Local/eximon.conf_&
2254 &_Local/eximon.conf-_&<&'ostype'&>
2255 &_Local/eximon.conf-_&<&'archtype'&>
2256 &_Local/eximon.conf-_&<&'ostype'&>-<&'archtype'&>
2257 .endd
2258 .cindex "&_Local/eximon.conf_&"
2259 As with Exim itself, the final three files need not exist, and in this case the
2260 &_OS/eximon.conf-<ostype>_& file is also optional. The default values in
2261 &_OS/eximon.conf-Default_& can be overridden dynamically by setting environment
2262 variables of the same name, preceded by EXIMON_. For example, setting
2263 EXIMON_LOG_DEPTH in the environment overrides the value of
2264 LOG_DEPTH at run time.
2265 .ecindex IIDbuex
2268 .section "Installing Exim binaries and scripts" "SECID32"
2269 .cindex "installing Exim"
2270 .cindex "BIN_DIRECTORY"
2271 The command &`make install`& runs the &(exim_install)& script with no
2272 arguments. The script copies binaries and utility scripts into the directory
2273 whose name is specified by the BIN_DIRECTORY setting in &_Local/Makefile_&.
2274 .cindex "setuid" "installing Exim with"
2275 The install script copies files only if they are newer than the files they are
2276 going to replace. The Exim binary is required to be owned by root and have the
2277 &'setuid'& bit set, for normal configurations. Therefore, you must run &`make
2278 install`& as root so that it can set up the Exim binary in this way. However, in
2279 some special situations (for example, if a host is doing no local deliveries)
2280 it may be possible to run Exim without making the binary setuid root (see
2281 chapter &<<CHAPsecurity>>& for details).
2283 .cindex "CONFIGURE_FILE"
2284 Exim's run time configuration file is named by the CONFIGURE_FILE setting
2285 in &_Local/Makefile_&. If this names a single file, and the file does not
2286 exist, the default configuration file &_src/configure.default_& is copied there
2287 by the installation script. If a run time configuration file already exists, it
2288 is left alone. If CONFIGURE_FILE is a colon-separated list, naming several
2289 alternative files, no default is installed.
2291 .cindex "system aliases file"
2292 .cindex "&_/etc/aliases_&"
2293 One change is made to the default configuration file when it is installed: the
2294 default configuration contains a router that references a system aliases file.
2295 The path to this file is set to the value specified by
2296 SYSTEM_ALIASES_FILE in &_Local/Makefile_& (&_/etc/aliases_& by default).
2297 If the system aliases file does not exist, the installation script creates it,
2298 and outputs a comment to the user.
2300 The created file contains no aliases, but it does contain comments about the
2301 aliases a site should normally have. Mail aliases have traditionally been
2302 kept in &_/etc/aliases_&. However, some operating systems are now using
2303 &_/etc/mail/aliases_&. You should check if yours is one of these, and change
2304 Exim's configuration if necessary.
2306 The default configuration uses the local host's name as the only local domain,
2307 and is set up to do local deliveries into the shared directory &_/var/mail_&,
2308 running as the local user. System aliases and &_.forward_& files in users' home
2309 directories are supported, but no NIS or NIS+ support is configured. Domains
2310 other than the name of the local host are routed using the DNS, with delivery
2311 over SMTP.
2313 It is possible to install Exim for special purposes (such as building a binary
2314 distribution) in a private part of the file system. You can do this by a
2315 command such as
2316 .code
2317 make DESTDIR=/some/directory/ install
2318 .endd
2319 This has the effect of pre-pending the specified directory to all the file
2320 paths, except the name of the system aliases file that appears in the default
2321 configuration. (If a default alias file is created, its name &'is'& modified.)
2322 For backwards compatibility, ROOT is used if DESTDIR is not set,
2323 but this usage is deprecated.
2325 .cindex "installing Exim" "what is not installed"
2326 Running &'make install'& does not copy the Exim 4 conversion script
2327 &'convert4r4'&. You will probably run this only once if you are
2328 upgrading from Exim 3. None of the documentation files in the &_doc_&
2329 directory are copied, except for the info files when you have set
2330 INFO_DIRECTORY, as described in section &<<SECTinsinfdoc>>& below.
2332 For the utility programs, old versions are renamed by adding the suffix &_.O_&
2333 to their names. The Exim binary itself, however, is handled differently. It is
2334 installed under a name that includes the version number and the compile number,
2335 for example &_exim-&version()-1_&. The script then arranges for a symbolic link
2336 called &_exim_& to point to the binary. If you are updating a previous version
2337 of Exim, the script takes care to ensure that the name &_exim_& is never absent
2338 from the directory (as seen by other processes).
2340 .cindex "installing Exim" "testing the script"
2341 If you want to see what the &'make install'& will do before running it for
2342 real, you can pass the &%-n%& option to the installation script by this
2343 command:
2344 .code
2345 make INSTALL_ARG=-n install
2346 .endd
2347 The contents of the variable INSTALL_ARG are passed to the installation
2348 script. You do not need to be root to run this test. Alternatively, you can run
2349 the installation script directly, but this must be from within the build
2350 directory. For example, from the top-level Exim directory you could use this
2351 command:
2352 .code
2353 (cd build-SunOS5-5.5.1-sparc; ../scripts/exim_install -n)
2354 .endd
2355 .cindex "installing Exim" "install script options"
2356 There are two other options that can be supplied to the installation script.
2358 .ilist
2359 &%-no_chown%& bypasses the call to change the owner of the installed binary
2360 to root, and the call to make it a setuid binary.
2361 .next
2362 &%-no_symlink%& bypasses the setting up of the symbolic link &_exim_& to the
2363 installed binary.
2364 .endlist
2366 INSTALL_ARG can be used to pass these options to the script. For example:
2367 .code
2368 make INSTALL_ARG=-no_symlink install
2369 .endd
2370 The installation script can also be given arguments specifying which files are
2371 to be copied. For example, to install just the Exim binary, and nothing else,
2372 without creating the symbolic link, you could use:
2373 .code
2374 make INSTALL_ARG='-no_symlink exim' install
2375 .endd
2379 .section "Installing info documentation" "SECTinsinfdoc"
2380 .cindex "installing Exim" "&'info'& documentation"
2381 Not all systems use the GNU &'info'& system for documentation, and for this
2382 reason, the Texinfo source of Exim's documentation is not included in the main
2383 distribution. Instead it is available separately from the ftp site (see section
2384 &<<SECTavail>>&).
2386 If you have defined INFO_DIRECTORY in &_Local/Makefile_& and the Texinfo
2387 source of the documentation is found in the source tree, running &`make
2388 install`& automatically builds the info files and installs them.
2392 .section "Setting up the spool directory" "SECID33"
2393 .cindex "spool directory" "creating"
2394 When it starts up, Exim tries to create its spool directory if it does not
2395 exist. The Exim uid and gid are used for the owner and group of the spool
2396 directory. Sub-directories are automatically created in the spool directory as
2397 necessary.
2402 .section "Testing" "SECID34"
2403 .cindex "testing" "installation"
2404 Having installed Exim, you can check that the run time configuration file is
2405 syntactically valid by running the following command, which assumes that the
2406 Exim binary directory is within your PATH environment variable:
2407 .code
2408 exim -bV
2409 .endd
2410 If there are any errors in the configuration file, Exim outputs error messages.
2411 Otherwise it outputs the version number and build date,
2412 the DBM library that is being used, and information about which drivers and
2413 other optional code modules are included in the binary.
2414 Some simple routing tests can be done by using the address testing option. For
2415 example,
2416 .display
2417 &`exim -bt`& <&'local username'&>
2418 .endd
2419 should verify that it recognizes a local mailbox, and
2420 .display
2421 &`exim -bt`& <&'remote address'&>
2422 .endd
2423 a remote one. Then try getting it to deliver mail, both locally and remotely.
2424 This can be done by passing messages directly to Exim, without going through a
2425 user agent. For example:
2426 .code
2427 exim -v postmaster@your.domain.example
2428 From: user@your.domain.example
2429 To: postmaster@your.domain.example
2430 Subject: Testing Exim
2432 This is a test message.
2433 ^D
2434 .endd
2435 The &%-v%& option causes Exim to output some verification of what it is doing.
2436 In this case you should see copies of three log lines, one for the message's
2437 arrival, one for its delivery, and one containing &"Completed"&.
2439 .cindex "delivery" "problems with"
2440 If you encounter problems, look at Exim's log files (&'mainlog'& and
2441 &'paniclog'&) to see if there is any relevant information there. Another source
2442 of information is running Exim with debugging turned on, by specifying the
2443 &%-d%& option. If a message is stuck on Exim's spool, you can force a delivery
2444 with debugging turned on by a command of the form
2445 .display
2446 &`exim -d -M`& <&'exim-message-id'&>
2447 .endd
2448 You must be root or an &"admin user"& in order to do this. The &%-d%& option
2449 produces rather a lot of output, but you can cut this down to specific areas.
2450 For example, if you use &%-d-all+route%& only the debugging information
2451 relevant to routing is included. (See the &%-d%& option in chapter
2452 &<<CHAPcommandline>>& for more details.)
2454 .cindex '&"sticky"& bit'
2455 .cindex "lock files"
2456 One specific problem that has shown up on some sites is the inability to do
2457 local deliveries into a shared mailbox directory, because it does not have the
2458 &"sticky bit"& set on it. By default, Exim tries to create a lock file before
2459 writing to a mailbox file, and if it cannot create the lock file, the delivery
2460 is deferred. You can get round this either by setting the &"sticky bit"& on the
2461 directory, or by setting a specific group for local deliveries and allowing
2462 that group to create files in the directory (see the comments above the
2463 &(local_delivery)& transport in the default configuration file). Another
2464 approach is to configure Exim not to use lock files, but just to rely on
2465 &[fcntl()]& locking instead. However, you should do this only if all user
2466 agents also use &[fcntl()]& locking. For further discussion of locking issues,
2467 see chapter &<<CHAPappendfile>>&.
2469 One thing that cannot be tested on a system that is already running an MTA is
2470 the receipt of incoming SMTP mail on the standard SMTP port. However, the
2471 &%-oX%& option can be used to run an Exim daemon that listens on some other
2472 port, or &'inetd'& can be used to do this. The &%-bh%& option and the
2473 &'exim_checkaccess'& utility can be used to check out policy controls on
2474 incoming SMTP mail.
2476 Testing a new version on a system that is already running Exim can most easily
2477 be done by building a binary with a different CONFIGURE_FILE setting. From
2478 within the run time configuration, all other file and directory names
2479 that Exim uses can be altered, in order to keep it entirely clear of the
2480 production version.
2483 .section "Replacing another MTA with Exim" "SECID35"
2484 .cindex "replacing another MTA"
2485 Building and installing Exim for the first time does not of itself put it in
2486 general use. The name by which the system's MTA is called by mail user agents
2487 is either &_/usr/sbin/sendmail_&, or &_/usr/lib/sendmail_& (depending on the
2488 operating system), and it is necessary to make this name point to the &'exim'&
2489 binary in order to get the user agents to pass messages to Exim. This is
2490 normally done by renaming any existing file and making &_/usr/sbin/sendmail_&
2491 or &_/usr/lib/sendmail_&
2492 .cindex "symbolic link" "to &'exim'& binary"
2493 a symbolic link to the &'exim'& binary. It is a good idea to remove any setuid
2494 privilege and executable status from the old MTA. It is then necessary to stop
2495 and restart the mailer daemon, if one is running.
2497 .cindex "FreeBSD, MTA indirection"
2498 .cindex "&_/etc/mail/mailer.conf_&"
2499 Some operating systems have introduced alternative ways of switching MTAs. For
2500 example, if you are running FreeBSD, you need to edit the file
2501 &_/etc/mail/mailer.conf_& instead of setting up a symbolic link as just
2502 described. A typical example of the contents of this file for running Exim is
2503 as follows:
2504 .code
2505 sendmail /usr/exim/bin/exim
2506 send-mail /usr/exim/bin/exim
2507 mailq /usr/exim/bin/exim -bp
2508 newaliases /usr/bin/true
2509 .endd
2510 Once you have set up the symbolic link, or edited &_/etc/mail/mailer.conf_&,
2511 your Exim installation is &"live"&. Check it by sending a message from your
2512 favourite user agent.
2514 You should consider what to tell your users about the change of MTA. Exim may
2515 have different capabilities to what was previously running, and there are
2516 various operational differences such as the text of messages produced by
2517 command line options and in bounce messages. If you allow your users to make
2518 use of Exim's filtering capabilities, you should make the document entitled
2519 &'Exim's interface to mail filtering'& available to them.
2523 .section "Upgrading Exim" "SECID36"
2524 .cindex "upgrading Exim"
2525 If you are already running Exim on your host, building and installing a new
2526 version automatically makes it available to MUAs, or any other programs that
2527 call the MTA directly. However, if you are running an Exim daemon, you do need
2528 to send it a HUP signal, to make it re-execute itself, and thereby pick up the
2529 new binary. You do not need to stop processing mail in order to install a new
2530 version of Exim. The install script does not modify an existing runtime
2531 configuration file.
2536 .section "Stopping the Exim daemon on Solaris" "SECID37"
2537 .cindex "Solaris" "stopping Exim on"
2538 The standard command for stopping the mailer daemon on Solaris is
2539 .code
2540 /etc/init.d/sendmail stop
2541 .endd
2542 If &_/usr/lib/sendmail_& has been turned into a symbolic link, this script
2543 fails to stop Exim because it uses the command &'ps -e'& and greps the output
2544 for the text &"sendmail"&; this is not present because the actual program name
2545 (that is, &"exim"&) is given by the &'ps'& command with these options. A
2546 solution is to replace the line that finds the process id with something like
2547 .code
2548 pid=`cat /var/spool/exim/`
2549 .endd
2550 to obtain the daemon's pid directly from the file that Exim saves it in.
2552 Note, however, that stopping the daemon does not &"stop Exim"&. Messages can
2553 still be received from local processes, and if automatic delivery is configured
2554 (the normal case), deliveries will still occur.
2559 . ////////////////////////////////////////////////////////////////////////////
2560 . ////////////////////////////////////////////////////////////////////////////
2562 .chapter "The Exim command line" "CHAPcommandline"
2563 .scindex IIDclo1 "command line" "options"
2564 .scindex IIDclo2 "options" "command line"
2565 Exim's command line takes the standard Unix form of a sequence of options,
2566 each starting with a hyphen character, followed by a number of arguments. The
2567 options are compatible with the main options of Sendmail, and there are also
2568 some additional options, some of which are compatible with Smail 3. Certain
2569 combinations of options do not make sense, and provoke an error if used.
2570 The form of the arguments depends on which options are set.
2573 .section "Setting options by program name" "SECID38"
2574 .cindex "&'mailq'&"
2575 If Exim is called under the name &'mailq'&, it behaves as if the option &%-bp%&
2576 were present before any other options.
2577 The &%-bp%& option requests a listing of the contents of the mail queue on the
2578 standard output.
2579 This feature is for compatibility with some systems that contain a command of
2580 that name in one of the standard libraries, symbolically linked to
2581 &_/usr/sbin/sendmail_& or &_/usr/lib/sendmail_&.
2583 .cindex "&'rsmtp'&"
2584 If Exim is called under the name &'rsmtp'& it behaves as if the option &%-bS%&
2585 were present before any other options, for compatibility with Smail. The
2586 &%-bS%& option is used for reading in a number of messages in batched SMTP
2587 format.
2589 .cindex "&'rmail'&"
2590 If Exim is called under the name &'rmail'& it behaves as if the &%-i%& and
2591 &%-oee%& options were present before any other options, for compatibility with
2592 Smail. The name &'rmail'& is used as an interface by some UUCP systems.
2594 .cindex "&'runq'&"
2595 .cindex "queue runner"
2596 If Exim is called under the name &'runq'& it behaves as if the option &%-q%&
2597 were present before any other options, for compatibility with Smail. The &%-q%&
2598 option causes a single queue runner process to be started.
2600 .cindex "&'newaliases'&"
2601 .cindex "alias file" "building"
2602 .cindex "Sendmail compatibility" "calling Exim as &'newaliases'&"
2603 If Exim is called under the name &'newaliases'& it behaves as if the option
2604 &%-bi%& were present before any other options, for compatibility with Sendmail.
2605 This option is used for rebuilding Sendmail's alias file. Exim does not have
2606 the concept of a single alias file, but can be configured to run a given
2607 command if called with the &%-bi%& option.
2610 .section "Trusted and admin users" "SECTtrustedadmin"
2611 Some Exim options are available only to &'trusted users'& and others are
2612 available only to &'admin users'&. In the description below, the phrases &"Exim
2613 user"& and &"Exim group"& mean the user and group defined by EXIM_USER and
2614 EXIM_GROUP in &_Local/Makefile_& or set by the &%exim_user%& and
2615 &%exim_group%& options. These do not necessarily have to use the name &"exim"&.
2617 .ilist
2618 .cindex "trusted users" "definition of"
2619 .cindex "user" "trusted definition of"
2620 The trusted users are root, the Exim user, any user listed in the
2621 &%trusted_users%& configuration option, and any user whose current group or any
2622 supplementary group is one of those listed in the &%trusted_groups%&
2623 configuration option. Note that the Exim group is not automatically trusted.
2625 .cindex '&"From"& line'
2626 .cindex "envelope sender"
2627 Trusted users are always permitted to use the &%-f%& option or a leading
2628 &"From&~"& line to specify the envelope sender of a message that is passed to
2629 Exim through the local interface (see the &%-bm%& and &%-f%& options below).
2630 See the &%untrusted_set_sender%& option for a way of permitting non-trusted
2631 users to set envelope senders.
2633 .cindex "&'From:'& header line"
2634 .cindex "&'Sender:'& header line"
2635 For a trusted user, there is never any check on the contents of the &'From:'&
2636 header line, and a &'Sender:'& line is never added. Furthermore, any existing
2637 &'Sender:'& line in incoming local (non-TCP/IP) messages is not removed.
2639 Trusted users may also specify a host name, host address, interface address,
2640 protocol name, ident value, and authentication data when submitting a message
2641 locally. Thus, they are able to insert messages into Exim's queue locally that
2642 have the characteristics of messages received from a remote host. Untrusted
2643 users may in some circumstances use &%-f%&, but can never set the other values
2644 that are available to trusted users.
2645 .next
2646 .cindex "user" "admin definition of"
2647 .cindex "admin user" "definition of"
2648 The admin users are root, the Exim user, and any user that is a member of the
2649 Exim group or of any group listed in the &%admin_groups%& configuration option.
2650 The current group does not have to be one of these groups.
2652 Admin users are permitted to list the queue, and to carry out certain
2653 operations on messages, for example, to force delivery failures. It is also
2654 necessary to be an admin user in order to see the full information provided by
2655 the Exim monitor, and full debugging output.
2657 By default, the use of the &%-M%&, &%-q%&, &%-R%&, and &%-S%& options to cause
2658 Exim to attempt delivery of messages on its queue is restricted to admin users.
2659 However, this restriction can be relaxed by setting the &%prod_requires_admin%&
2660 option false (that is, specifying &%no_prod_requires_admin%&).
2662 Similarly, the use of the &%-bp%& option to list all the messages in the queue
2663 is restricted to admin users unless &%queue_list_requires_admin%& is set
2664 false.
2665 .endlist
2668 &*Warning*&: If you configure your system so that admin users are able to
2669 edit Exim's configuration file, you are giving those users an easy way of
2670 getting root. There is further discussion of this issue at the start of chapter
2671 &<<CHAPconf>>&.
2676 .section "Command line options" "SECID39"
2677 Exim's command line options are described in alphabetical order below. If none
2678 of the options that specifies a specific action (such as starting the daemon or
2679 a queue runner, or testing an address, or receiving a message in a specific
2680 format, or listing the queue) are present, and there is at least one argument
2681 on the command line, &%-bm%& (accept a local message on the standard input,
2682 with the arguments specifying the recipients) is assumed. Otherwise, Exim
2683 outputs a brief message about itself and exits.
2685 . ////////////////////////////////////////////////////////////////////////////
2686 . Insert a stylized XML comment here, to identify the start of the command line
2687 . options. This is for the benefit of the Perl script that automatically
2688 . creates a man page for the options.
2689 . ////////////////////////////////////////////////////////////////////////////
2691 .literal xml
2692 <!-- === Start of command line options === -->
2693 .literal off
2696 .vlist
2697 .vitem &%--%&
2698 .oindex "--"
2699 .cindex "options" "command line; terminating"
2700 This is a pseudo-option whose only purpose is to terminate the options and
2701 therefore to cause subsequent command line items to be treated as arguments
2702 rather than options, even if they begin with hyphens.
2704 .vitem &%--help%&
2705 .oindex "&%--help%&"
2706 This option causes Exim to output a few sentences stating what it is.
2707 The same output is generated if the Exim binary is called with no options and
2708 no arguments.
2710 .vitem &%--version%&
2711 .oindex "&%--version%&"
2712 This option is an alias for &%-bV%& and causes version information to be
2713 displayed.
2715 .vitem &%-Ac%& &&&
2716 &%-Am%&
2717 .oindex "&%-Ac%&"
2718 .oindex "&%-Am%&"
2719 These options are used by Sendmail for selecting configuration files and are
2720 ignored by Exim.
2722 .vitem &%-B%&<&'type'&>
2723 .oindex "&%-B%&"
2724 .cindex "8-bit characters"
2725 .cindex "Sendmail compatibility" "8-bit characters"
2726 This is a Sendmail option for selecting 7 or 8 bit processing. Exim is 8-bit
2727 clean; it ignores this option.
2729 .vitem &%-bd%&
2730 .oindex "&%-bd%&"
2731 .cindex "daemon"
2732 .cindex "SMTP" "listener"
2733 .cindex "queue runner"
2734 This option runs Exim as a daemon, awaiting incoming SMTP connections. Usually
2735 the &%-bd%& option is combined with the &%-q%&<&'time'&> option, to specify
2736 that the daemon should also initiate periodic queue runs.
2738 The &%-bd%& option can be used only by an admin user. If either of the &%-d%&
2739 (debugging) or &%-v%& (verifying) options are set, the daemon does not
2740 disconnect from the controlling terminal. When running this way, it can be
2741 stopped by pressing ctrl-C.
2743 By default, Exim listens for incoming connections to the standard SMTP port on
2744 all the host's running interfaces. However, it is possible to listen on other
2745 ports, on multiple ports, and only on specific interfaces. Chapter
2746 &<<CHAPinterfaces>>& contains a description of the options that control this.
2748 When a listening daemon
2749 .cindex "daemon" "process id (pid)"
2750 .cindex "pid (process id)" "of daemon"
2751 is started without the use of &%-oX%& (that is, without overriding the normal
2752 configuration), it writes its process id to a file called &_exim-daemon.pid_&
2753 in Exim's spool directory. This location can be overridden by setting
2754 PID_FILE_PATH in &_Local/Makefile_&. The file is written while Exim is still
2755 running as root.
2757 When &%-oX%& is used on the command line to start a listening daemon, the
2758 process id is not written to the normal pid file path. However, &%-oP%& can be
2759 used to specify a path on the command line if a pid file is required.
2761 The SIGHUP signal
2762 .cindex "SIGHUP"
2763 .cindex "daemon" "restarting"
2764 can be used to cause the daemon to re-execute itself. This should be done
2765 whenever Exim's configuration file, or any file that is incorporated into it by
2766 means of the &%.include%& facility, is changed, and also whenever a new version
2767 of Exim is installed. It is not necessary to do this when other files that are
2768 referenced from the configuration (for example, alias files) are changed,
2769 because these are reread each time they are used.
2771 .vitem &%-bdf%&
2772 .oindex "&%-bdf%&"
2773 This option has the same effect as &%-bd%& except that it never disconnects
2774 from the controlling terminal, even when no debugging is specified.
2776 .vitem &%-be%&
2777 .oindex "&%-be%&"
2778 .cindex "testing" "string expansion"
2779 .cindex "expansion" "testing"
2780 Run Exim in expansion testing mode. Exim discards its root privilege, to
2781 prevent ordinary users from using this mode to read otherwise inaccessible
2782 files. If no arguments are given, Exim runs interactively, prompting for lines
2783 of data. Otherwise, it processes each argument in turn.
2785 If Exim was built with USE_READLINE=yes in &_Local/Makefile_&, it tries
2786 to load the &%libreadline%& library dynamically whenever the &%-be%& option is
2787 used without command line arguments. If successful, it uses the &[readline()]&
2788 function, which provides extensive line-editing facilities, for reading the
2789 test data. A line history is supported.
2791 Long expansion expressions can be split over several lines by using backslash
2792 continuations. As in Exim's run time configuration, white space at the start of
2793 continuation lines is ignored. Each argument or data line is passed through the
2794 string expansion mechanism, and the result is output. Variable values from the
2795 configuration file (for example, &$qualify_domain$&) are available, but no
2796 message-specific values (such as &$sender_domain$&) are set, because no message
2797 is being processed (but see &%-bem%& and &%-Mset%&).
2799 &*Note*&: If you use this mechanism to test lookups, and you change the data
2800 files or databases you are using, you must exit and restart Exim before trying
2801 the same lookup again. Otherwise, because each Exim process caches the results
2802 of lookups, you will just get the same result as before.
2804 .vitem &%-bem%&&~<&'filename'&>
2805 .oindex "&%-bem%&"
2806 .cindex "testing" "string expansion"
2807 .cindex "expansion" "testing"
2808 This option operates like &%-be%& except that it must be followed by the name
2809 of a file. For example:
2810 .code
2811 exim -bem /tmp/testmessage
2812 .endd
2813 The file is read as a message (as if receiving a locally-submitted non-SMTP
2814 message) before any of the test expansions are done. Thus, message-specific
2815 variables such as &$message_size$& and &$header_from:$& are available. However,
2816 no &'Received:'& header is added to the message. If the &%-t%& option is set,
2817 recipients are read from the headers in the normal way, and are shown in the
2818 &$recipients$& variable. Note that recipients cannot be given on the command
2819 line, because further arguments are taken as strings to expand (just like
2820 &%-be%&).
2822 .vitem &%-bF%&&~<&'filename'&>
2823 .oindex "&%-bF%&"
2824 .cindex "system filter" "testing"
2825 .cindex "testing" "system filter"
2826 This option is the same as &%-bf%& except that it assumes that the filter being
2827 tested is a system filter. The additional commands that are available only in
2828 system filters are recognized.
2830 .vitem &%-bf%&&~<&'filename'&>
2831 .oindex "&%-bf%&"
2832 .cindex "filter" "testing"
2833 .cindex "testing" "filter file"
2834 .cindex "forward file" "testing"
2835 .cindex "testing" "forward file"
2836 .cindex "Sieve filter" "testing"
2837 This option runs Exim in user filter testing mode; the file is the filter file
2838 to be tested, and a test message must be supplied on the standard input. If
2839 there are no message-dependent tests in the filter, an empty file can be
2840 supplied.
2842 If you want to test a system filter file, use &%-bF%& instead of &%-bf%&. You
2843 can use both &%-bF%& and &%-bf%& on the same command, in order to test a system
2844 filter and a user filter in the same run. For example:
2845 .code
2846 exim -bF /system/filter -bf /user/filter </test/message
2847 .endd
2848 This is helpful when the system filter adds header lines or sets filter
2849 variables that are used by the user filter.
2851 If the test filter file does not begin with one of the special lines
2852 .code
2853 # Exim filter
2854 # Sieve filter
2855 .endd
2856 it is taken to be a normal &_.forward_& file, and is tested for validity under
2857 that interpretation. See sections &<<SECTitenonfilred>>& to
2858 &<<SECTspecitredli>>& for a description of the possible contents of non-filter
2859 redirection lists.
2861 The result of an Exim command that uses &%-bf%&, provided no errors are
2862 detected, is a list of the actions that Exim would try to take if presented
2863 with the message for real. More details of filter testing are given in the
2864 separate document entitled &'Exim's interfaces to mail filtering'&.
2866 When testing a filter file,
2867 .cindex "&""From""& line"
2868 .cindex "envelope sender"
2869 .oindex "&%-f%&" "for filter testing"
2870 the envelope sender can be set by the &%-f%& option,
2871 or by a &"From&~"& line at the start of the test message. Various parameters
2872 that would normally be taken from the envelope recipient address of the message
2873 can be set by means of additional command line options (see the next four
2874 options).
2876 .vitem &%-bfd%&&~<&'domain'&>
2877 .oindex "&%-bfd%&"
2878 .vindex "&$qualify_domain$&"
2879 This sets the domain of the recipient address when a filter file is being
2880 tested by means of the &%-bf%& option. The default is the value of
2881 &$qualify_domain$&.
2883 .vitem &%-bfl%&&~<&'local&~part'&>
2884 .oindex "&%-bfl%&"
2885 This sets the local part of the recipient address when a filter file is being
2886 tested by means of the &%-bf%& option. The default is the username of the
2887 process that calls Exim. A local part should be specified with any prefix or
2888 suffix stripped, because that is how it appears to the filter when a message is
2889 actually being delivered.
2891 .vitem &%-bfp%&&~<&'prefix'&>
2892 .oindex "&%-bfp%&"
2893 This sets the prefix of the local part of the recipient address when a filter
2894 file is being tested by means of the &%-bf%& option. The default is an empty
2895 prefix.
2897 .vitem &%-bfs%&&~<&'suffix'&>
2898 .oindex "&%-bfs%&"
2899 This sets the suffix of the local part of the recipient address when a filter
2900 file is being tested by means of the &%-bf%& option. The default is an empty
2901 suffix.
2903 .vitem &%-bh%&&~<&'IP&~address'&>
2904 .oindex "&%-bh%&"
2905 .cindex "testing" "incoming SMTP"
2906 .cindex "SMTP" "testing incoming"
2907 .cindex "testing" "relay control"
2908 .cindex "relaying" "testing configuration"
2909 .cindex "policy control" "testing"
2910 .cindex "debugging" "&%-bh%& option"
2911 This option runs a fake SMTP session as if from the given IP address, using the
2912 standard input and output. The IP address may include a port number at the end,
2913 after a full stop. For example:
2914 .code
2915 exim -bh
2916 exim -bh fe80::a00:20ff:fe86:a061.5678
2917 .endd
2918 When an IPv6 address is given, it is converted into canonical form. In the case
2919 of the second example above, the value of &$sender_host_address$& after
2920 conversion to the canonical form is
2921 &`fe80:0000:0000:0a00:20ff:fe86:a061.5678`&.
2923 Comments as to what is going on are written to the standard error file. These
2924 include lines beginning with &"LOG"& for anything that would have been logged.
2925 This facility is provided for testing configuration options for incoming
2926 messages, to make sure they implement the required policy. For example, you can
2927 test your relay controls using &%-bh%&.
2929 &*Warning 1*&:
2930 .cindex "RFC 1413"
2931 You can test features of the configuration that rely on ident (RFC 1413)
2932 information by using the &%-oMt%& option. However, Exim cannot actually perform
2933 an ident callout when testing using &%-bh%& because there is no incoming SMTP
2934 connection.
2936 &*Warning 2*&: Address verification callouts (see section &<<SECTcallver>>&)
2937 are also skipped when testing using &%-bh%&. If you want these callouts to
2938 occur, use &%-bhc%& instead.
2940 Messages supplied during the testing session are discarded, and nothing is
2941 written to any of the real log files. There may be pauses when DNS (and other)
2942 lookups are taking place, and of course these may time out. The &%-oMi%& option
2943 can be used to specify a specific IP interface and port if this is important,
2944 and &%-oMaa%& and &%-oMai%& can be used to set parameters as if the SMTP
2945 session were authenticated.
2947 The &'exim_checkaccess'& utility is a &"packaged"& version of &%-bh%& whose
2948 output just states whether a given recipient address from a given host is
2949 acceptable or not. See section &<<SECTcheckaccess>>&.
2951 Features such as authentication and encryption, where the client input is not
2952 plain text, cannot easily be tested with &%-bh%&. Instead, you should use a
2953 specialized SMTP test program such as
2954 &url(,swaks).
2956 .vitem &%-bhc%&&~<&'IP&~address'&>
2957 .oindex "&%-bhc%&"
2958 This option operates in the same way as &%-bh%&, except that address
2959 verification callouts are performed if required. This includes consulting and
2960 updating the callout cache database.
2962 .vitem &%-bi%&
2963 .oindex "&%-bi%&"
2964 .cindex "alias file" "building"
2965 .cindex "building alias file"
2966 .cindex "Sendmail compatibility" "&%-bi%& option"
2967 Sendmail interprets the &%-bi%& option as a request to rebuild its alias file.
2968 Exim does not have the concept of a single alias file, and so it cannot mimic
2969 this behaviour. However, calls to &_/usr/lib/sendmail_& with the &%-bi%& option
2970 tend to appear in various scripts such as NIS make files, so the option must be
2971 recognized.
2973 If &%-bi%& is encountered, the command specified by the &%bi_command%&
2974 configuration option is run, under the uid and gid of the caller of Exim. If
2975 the &%-oA%& option is used, its value is passed to the command as an argument.
2976 The command set by &%bi_command%& may not contain arguments. The command can
2977 use the &'exim_dbmbuild'& utility, or some other means, to rebuild alias files
2978 if this is required. If the &%bi_command%& option is not set, calling Exim with
2979 &%-bi%& is a no-op.
2981 . // Keep :help first, then the rest in alphabetical order
2982 .vitem &%-bI:help%&
2983 .oindex "&%-bI:help%&"
2984 .cindex "querying exim information"
2985 We shall provide various options starting &`-bI:`& for querying Exim for
2986 information. The output of many of these will be intended for machine
2987 consumption. This one is not. The &%-bI:help%& option asks Exim for a
2988 synopsis of supported options beginning &`-bI:`&. Use of any of these
2989 options shall cause Exim to exit after producing the requested output.
2991 .vitem &%-bI:dscp%&
2992 .oindex "&%-bI:dscp%&"
2993 .cindex "DSCP" "values"
2994 This option causes Exim to emit an alphabetically sorted list of all
2995 recognised DSCP names.
2997 .vitem &%-bI:sieve%&
2998 .oindex "&%-bI:sieve%&"
2999 .cindex "Sieve filter" "capabilities"
3000 This option causes Exim to emit an alphabetically sorted list of all supported
3001 Sieve protocol extensions on stdout, one per line. This is anticipated to be
3002 useful for ManageSieve (RFC 5804) implementations, in providing that protocol's
3003 &`SIEVE`& capability response line. As the precise list may depend upon
3004 compile-time build options, which this option will adapt to, this is the only
3005 way to guarantee a correct response.
3007 .vitem &%-bm%&
3008 .oindex "&%-bm%&"
3009 .cindex "local message reception"
3010 This option runs an Exim receiving process that accepts an incoming,
3011 locally-generated message on the standard input. The recipients are given as the
3012 command arguments (except when &%-t%& is also present &-- see below). Each
3013 argument can be a comma-separated list of RFC 2822 addresses. This is the
3014 default option for selecting the overall action of an Exim call; it is assumed
3015 if no other conflicting option is present.
3017 If any addresses in the message are unqualified (have no domain), they are
3018 qualified by the values of the &%qualify_domain%& or &%qualify_recipient%&
3019 options, as appropriate. The &%-bnq%& option (see below) provides a way of
3020 suppressing this for special cases.
3022 Policy checks on the contents of local messages can be enforced by means of
3023 the non-SMTP ACL. See chapter &<<CHAPACL>>& for details.
3025 .cindex "return code" "for &%-bm%&"
3026 The return code is zero if the message is successfully accepted. Otherwise, the
3027 action is controlled by the &%-oe%&&'x'& option setting &-- see below.
3029 The format
3030 .cindex "message" "format"
3031 .cindex "format" "message"
3032 .cindex "&""From""& line"
3033 .cindex "UUCP" "&""From""& line"
3034 .cindex "Sendmail compatibility" "&""From""& line"
3035 of the message must be as defined in RFC 2822, except that, for
3036 compatibility with Sendmail and Smail, a line in one of the forms
3037 .code
3038 From sender Fri Jan 5 12:55 GMT 1997
3039 From sender Fri, 5 Jan 97 12:55:01
3040 .endd
3041 (with the weekday optional, and possibly with additional text after the date)
3042 is permitted to appear at the start of the message. There appears to be no
3043 authoritative specification of the format of this line. Exim recognizes it by
3044 matching against the regular expression defined by the &%uucp_from_pattern%&
3045 option, which can be changed if necessary.
3047 .oindex "&%-f%&" "overriding &""From""& line"
3048 The specified sender is treated as if it were given as the argument to the
3049 &%-f%& option, but if a &%-f%& option is also present, its argument is used in
3050 preference to the address taken from the message. The caller of Exim must be a
3051 trusted user for the sender of a message to be set in this way.
3053 .vitem &%-bmalware%&&~<&'filename'&>
3054 .oindex "&%-bmalware%&"
3055 .cindex "testing", "malware"
3056 .cindex "malware scan test"
3057 This debugging option causes Exim to scan the given file,
3058 using the malware scanning framework. The option of &%av_scanner%& influences
3059 this option, so if &%av_scanner%&'s value is dependent upon an expansion then
3060 the expansion should have defaults which apply to this invocation. ACLs are
3061 not invoked, so if &%av_scanner%& references an ACL variable then that variable
3062 will never be populated and &%-bmalware%& will fail.
3064 Exim will have changed working directory before resolving the filename, so
3065 using fully qualified pathnames is advisable. Exim will be running as the Exim
3066 user when it tries to open the file, rather than as the invoking user.
3067 This option requires admin privileges.
3069 The &%-bmalware%& option will not be extended to be more generally useful,
3070 there are better tools for file-scanning. This option exists to help
3071 administrators verify their Exim and AV scanner configuration.
3073 .vitem &%-bnq%&
3074 .oindex "&%-bnq%&"
3075 .cindex "address qualification, suppressing"
3076 By default, Exim automatically qualifies unqualified addresses (those
3077 without domains) that appear in messages that are submitted locally (that
3078 is, not over TCP/IP). This qualification applies both to addresses in
3079 envelopes, and addresses in header lines. Sender addresses are qualified using
3080 &%qualify_domain%&, and recipient addresses using &%qualify_recipient%& (which
3081 defaults to the value of &%qualify_domain%&).
3083 Sometimes, qualification is not wanted. For example, if &%-bS%& (batch SMTP) is
3084 being used to re-submit messages that originally came from remote hosts after
3085 content scanning, you probably do not want to qualify unqualified addresses in
3086 header lines. (Such lines will be present only if you have not enabled a header
3087 syntax check in the appropriate ACL.)
3089 The &%-bnq%& option suppresses all qualification of unqualified addresses in
3090 messages that originate on the local host. When this is used, unqualified
3091 addresses in the envelope provoke errors (causing message rejection) and
3092 unqualified addresses in header lines are left alone.
3095 .vitem &%-bP%&
3096 .oindex "&%-bP%&"
3097 .cindex "configuration options" "extracting"
3098 .cindex "options" "configuration &-- extracting"
3099 If this option is given with no arguments, it causes the values of all Exim's
3100 main configuration options to be written to the standard output. The values
3101 of one or more specific options can be requested by giving their names as
3102 arguments, for example:
3103 .code
3104 exim -bP qualify_domain hold_domains
3105 .endd
3106 .cindex "hiding configuration option values"
3107 .cindex "configuration options" "hiding value of"
3108 .cindex "options" "hiding value of"
3109 However, any option setting that is preceded by the word &"hide"& in the
3110 configuration file is not shown in full, except to an admin user. For other
3111 users, the output is as in this example:
3112 .code
3113 mysql_servers = <value not displayable>
3114 .endd
3115 If &%configure_file%& is given as an argument, the name of the run time
3116 configuration file is output.
3117 If a list of configuration files was supplied, the value that is output here
3118 is the name of the file that was actually used.
3120 .cindex "options" "hiding name of"
3121 If the &%-n%& flag is given, then for most modes of &%-bP%& operation the
3122 name will not be output.
3124 .cindex "daemon" "process id (pid)"
3125 .cindex "pid (process id)" "of daemon"
3126 If &%log_file_path%& or &%pid_file_path%& are given, the names of the
3127 directories where log files and daemon pid files are written are output,
3128 respectively. If these values are unset, log files are written in a
3129 sub-directory of the spool directory called &%log%&, and the pid file is
3130 written directly into the spool directory.
3132 If &%-bP%& is followed by a name preceded by &`+`&, for example,
3133 .code
3134 exim -bP +local_domains
3135 .endd
3136 it searches for a matching named list of any type (domain, host, address, or
3137 local part) and outputs what it finds.
3139 .cindex "options" "router &-- extracting"
3140 .cindex "options" "transport &-- extracting"
3141 .cindex "options" "authenticator &-- extracting"
3142 If one of the words &%router%&, &%transport%&, or &%authenticator%& is given,
3143 followed by the name of an appropriate driver instance, the option settings for
3144 that driver are output. For example:
3145 .code
3146 exim -bP transport local_delivery
3147 .endd
3148 The generic driver options are output first, followed by the driver's private
3149 options. A list of the names of drivers of a particular type can be obtained by
3150 using one of the words &%router_list%&, &%transport_list%&, or
3151 &%authenticator_list%&, and a complete list of all drivers with their option
3152 settings can be obtained by using &%routers%&, &%transports%&, or
3153 &%authenticators%&.
3155 .cindex "options" "macro &-- extracting"
3156 If invoked by an admin user, then &%macro%&, &%macro_list%& and &%macros%&
3157 are available, similarly to the drivers. Because macros are sometimes used
3158 for storing passwords, this option is restricted.
3159 The output format is one item per line.
3161 .vitem &%-bp%&
3162 .oindex "&%-bp%&"
3163 .cindex "queue" "listing messages on"
3164 .cindex "listing" "messages on the queue"
3165 This option requests a listing of the contents of the mail queue on the
3166 standard output. If the &%-bp%& option is followed by a list of message ids,
3167 just those messages are listed. By default, this option can be used only by an
3168 admin user. However, the &%queue_list_requires_admin%& option can be set false
3169 to allow any user to see the queue.
3171 Each message on the queue is displayed as in the following example:
3172 .code
3173 25m 2.9K 0t5C6f-0000c8-00 <alice@wonderland.fict.example>
3174 red.king@looking-glass.fict.example
3175 <other addresses>
3176 .endd
3177 .cindex "message" "size in queue listing"
3178 .cindex "size" "of message"
3179 The first line contains the length of time the message has been on the queue
3180 (in this case 25 minutes), the size of the message (2.9K), the unique local
3181 identifier for the message, and the message sender, as contained in the
3182 envelope. For bounce messages, the sender address is empty, and appears as
3183 &"<>"&. If the message was submitted locally by an untrusted user who overrode
3184 the default sender address, the user's login name is shown in parentheses
3185 before the sender address.
3187 .cindex "frozen messages" "in queue listing"
3188 If the message is frozen (attempts to deliver it are suspended) then the text
3189 &"*** frozen ***"& is displayed at the end of this line.
3191 The recipients of the message (taken from the envelope, not the headers) are
3192 displayed on subsequent lines. Those addresses to which the message has already
3193 been delivered are marked with the letter D. If an original address gets
3194 expanded into several addresses via an alias or forward file, the original is
3195 displayed with a D only when deliveries for all of its child addresses are
3196 complete.
3199 .vitem &%-bpa%&
3200 .oindex "&%-bpa%&"
3201 This option operates like &%-bp%&, but in addition it shows delivered addresses
3202 that were generated from the original top level address(es) in each message by
3203 alias or forwarding operations. These addresses are flagged with &"+D"& instead
3204 of just &"D"&.
3207 .vitem &%-bpc%&
3208 .oindex "&%-bpc%&"
3209 .cindex "queue" "count of messages on"
3210 This option counts the number of messages on the queue, and writes the total
3211 to the standard output. It is restricted to admin users, unless
3212 &%queue_list_requires_admin%& is set false.
3215 .vitem &%-bpr%&
3216 .oindex "&%-bpr%&"
3217 This option operates like &%-bp%&, but the output is not sorted into
3218 chronological order of message arrival. This can speed it up when there are
3219 lots of messages on the queue, and is particularly useful if the output is
3220 going to be post-processed in a way that doesn't need the sorting.
3222 .vitem &%-bpra%&
3223 .oindex "&%-bpra%&"
3224 This option is a combination of &%-bpr%& and &%-bpa%&.
3226 .vitem &%-bpru%&
3227 .oindex "&%-bpru%&"
3228 This option is a combination of &%-bpr%& and &%-bpu%&.
3231 .vitem &%-bpu%&
3232 .oindex "&%-bpu%&"
3233 This option operates like &%-bp%& but shows only undelivered top-level
3234 addresses for each message displayed. Addresses generated by aliasing or
3235 forwarding are not shown, unless the message was deferred after processing by a
3236 router with the &%one_time%& option set.
3239 .vitem &%-brt%&
3240 .oindex "&%-brt%&"
3241 .cindex "testing" "retry configuration"
3242 .cindex "retry" "configuration testing"
3243 This option is for testing retry rules, and it must be followed by up to three
3244 arguments. It causes Exim to look for a retry rule that matches the values
3245 and to write it to the standard output. For example:
3246 .code
3247 exim -brt bach.comp.mus.example
3248 Retry rule: *.comp.mus.example F,2h,15m; F,4d,30m;
3249 .endd
3250 See chapter &<<CHAPretry>>& for a description of Exim's retry rules. The first
3251 argument, which is required, can be a complete address in the form
3252 &'local_part@domain'&, or it can be just a domain name. If the second argument
3253 contains a dot, it is interpreted as an optional second domain name; if no
3254 retry rule is found for the first argument, the second is tried. This ties in
3255 with Exim's behaviour when looking for retry rules for remote hosts &-- if no
3256 rule is found that matches the host, one that matches the mail domain is
3257 sought. Finally, an argument that is the name of a specific delivery error, as
3258 used in setting up retry rules, can be given. For example:
3259 .code
3260 exim -brt haydn.comp.mus.example quota_3d
3261 Retry rule: *@haydn.comp.mus.example quota_3d F,1h,15m
3262 .endd
3264 .vitem &%-brw%&
3265 .oindex "&%-brw%&"
3266 .cindex "testing" "rewriting"
3267 .cindex "rewriting" "testing"
3268 This option is for testing address rewriting rules, and it must be followed by
3269 a single argument, consisting of either a local part without a domain, or a
3270 complete address with a fully qualified domain. Exim outputs how this address
3271 would be rewritten for each possible place it might appear. See chapter
3272 &<<CHAPrewrite>>& for further details.
3274 .vitem &%-bS%&
3275 .oindex "&%-bS%&"
3276 .cindex "SMTP" "batched incoming"
3277 .cindex "batched SMTP input"
3278 This option is used for batched SMTP input, which is an alternative interface
3279 for non-interactive local message submission. A number of messages can be
3280 submitted in a single run. However, despite its name, this is not really SMTP
3281 input. Exim reads each message's envelope from SMTP commands on the standard
3282 input, but generates no responses. If the caller is trusted, or
3283 &%untrusted_set_sender%& is set, the senders in the SMTP MAIL commands are
3284 believed; otherwise the sender is always the caller of Exim.
3286 The message itself is read from the standard input, in SMTP format (leading
3287 dots doubled), terminated by a line containing just a single dot. An error is
3288 provoked if the terminating dot is missing. A further message may then follow.
3290 As for other local message submissions, the contents of incoming batch SMTP
3291 messages can be checked using the non-SMTP ACL (see chapter &<<CHAPACL>>&).
3292 Unqualified addresses are automatically qualified using &%qualify_domain%& and
3293 &%qualify_recipient%&, as appropriate, unless the &%-bnq%& option is used.
3295 Some other SMTP commands are recognized in the input. HELO and EHLO act
3296 as RSET; VRFY, EXPN, ETRN, and HELP act as NOOP;
3297 QUIT quits, ignoring the rest of the standard input.
3299 .cindex "return code" "for &%-bS%&"
3300 If any error is encountered, reports are written to the standard output and
3301 error streams, and Exim gives up immediately. The return code is 0 if no error
3302 was detected; it is 1 if one or more messages were accepted before the error
3303 was detected; otherwise it is 2.
3305 More details of input using batched SMTP are given in section
3306 &<<SECTincomingbatchedSMTP>>&.
3308 .vitem &%-bs%&
3309 .oindex "&%-bs%&"
3310 .cindex "SMTP" "local input"
3311 .cindex "local SMTP input"
3312 This option causes Exim to accept one or more messages by reading SMTP commands
3313 on the standard input, and producing SMTP replies on the standard output. SMTP
3314 policy controls, as defined in ACLs (see chapter &<<CHAPACL>>&) are applied.
3315 Some user agents use this interface as a way of passing locally-generated
3316 messages to the MTA.
3318 In
3319 .cindex "sender" "source of"
3320 this usage, if the caller of Exim is trusted, or &%untrusted_set_sender%& is
3321 set, the senders of messages are taken from the SMTP MAIL commands.
3322 Otherwise the content of these commands is ignored and the sender is set up as
3323 the calling user. Unqualified addresses are automatically qualified using
3324 &%qualify_domain%& and &%qualify_recipient%&, as appropriate, unless the
3325 &%-bnq%& option is used.
3327 .cindex "inetd"
3328 The
3329 &%-bs%& option is also used to run Exim from &'inetd'&, as an alternative to
3330 using a listening daemon. Exim can distinguish the two cases by checking
3331 whether the standard input is a TCP/IP socket. When Exim is called from
3332 &'inetd'&, the source of the mail is assumed to be remote, and the comments
3333 above concerning senders and qualification do not apply. In this situation,
3334 Exim behaves in exactly the same way as it does when receiving a message via
3335 the listening daemon.
3337 .vitem &%-bt%&
3338 .oindex "&%-bt%&"
3339 .cindex "testing" "addresses"
3340 .cindex "address" "testing"
3341 This option runs Exim in address testing mode, in which each argument is taken
3342 as a recipient address to be tested for deliverability. The results are
3343 written to the standard output. If a test fails, and the caller is not an admin
3344 user, no details of the failure are output, because these might contain
3345 sensitive information such as usernames and passwords for database lookups.
3347 If no arguments are given, Exim runs in an interactive manner, prompting with a
3348 right angle bracket for addresses to be tested.
3350 Unlike the &%-be%& test option, you cannot arrange for Exim to use the
3351 &[readline()]& function, because it is running as &'root'& and there are
3352 security issues.
3354 Each address is handled as if it were the recipient address of a message
3355 (compare the &%-bv%& option). It is passed to the routers and the result is
3356 written to the standard output. However, any router that has
3357 &%no_address_test%& set is bypassed. This can make &%-bt%& easier to use for
3358 genuine routing tests if your first router passes everything to a scanner
3359 program.
3361 .cindex "return code" "for &%-bt%&"
3362 The return code is 2 if any address failed outright; it is 1 if no address
3363 failed outright but at least one could not be resolved for some reason. Return
3364 code 0 is given only when all addresses succeed.
3366 .cindex "duplicate addresses"
3367 &*Note*&: When actually delivering a message, Exim removes duplicate recipient
3368 addresses after routing is complete, so that only one delivery takes place.
3369 This does not happen when testing with &%-bt%&; the full results of routing are
3370 always shown.
3372 &*Warning*&: &%-bt%& can only do relatively simple testing. If any of the
3373 routers in the configuration makes any tests on the sender address of a
3374 message,
3375 .oindex "&%-f%&" "for address testing"
3376 you can use the &%-f%& option to set an appropriate sender when running
3377 &%-bt%& tests. Without it, the sender is assumed to be the calling user at the
3378 default qualifying domain. However, if you have set up (for example) routers
3379 whose behaviour depends on the contents of an incoming message, you cannot test
3380 those conditions using &%-bt%&. The &%-N%& option provides a possible way of
3381 doing such tests.
3383 .vitem &%-bV%&
3384 .oindex "&%-bV%&"
3385 .cindex "version number of Exim"
3386 This option causes Exim to write the current version number, compilation
3387 number, and compilation date of the &'exim'& binary to the standard output.
3388 It also lists the DBM library that is being used, the optional modules (such as
3389 specific lookup types), the drivers that are included in the binary, and the
3390 name of the run time configuration file that is in use.
3392 As part of its operation, &%-bV%& causes Exim to read and syntax check its
3393 configuration file. However, this is a static check only. It cannot check
3394 values that are to be expanded. For example, although a misspelt ACL verb is
3395 detected, an error in the verb's arguments is not. You cannot rely on &%-bV%&
3396 alone to discover (for example) all the typos in the configuration; some
3397 realistic testing is needed. The &%-bh%& and &%-N%& options provide more
3398 dynamic testing facilities.
3400 .vitem &%-bv%&
3401 .oindex "&%-bv%&"
3402 .cindex "verifying address" "using &%-bv%&"
3403 .cindex "address" "verification"
3404 This option runs Exim in address verification mode, in which each argument is
3405 taken as a recipient address to be verified by the routers. (This does
3406 not involve any verification callouts). During normal operation, verification
3407 happens mostly as a consequence processing a &%verify%& condition in an ACL
3408 (see chapter &<<CHAPACL>>&). If you want to test an entire ACL, possibly
3409 including callouts, see the &%-bh%& and &%-bhc%& options.
3411 If verification fails, and the caller is not an admin user, no details of the
3412 failure are output, because these might contain sensitive information such as
3413 usernames and passwords for database lookups.
3415 If no arguments are given, Exim runs in an interactive manner, prompting with a
3416 right angle bracket for addresses to be verified.
3418 Unlike the &%-be%& test option, you cannot arrange for Exim to use the
3419 &[readline()]& function, because it is running as &'exim'& and there are
3420 security issues.
3422 Verification differs from address testing (the &%-bt%& option) in that routers
3423 that have &%no_verify%& set are skipped, and if the address is accepted by a
3424 router that has &%fail_verify%& set, verification fails. The address is
3425 verified as a recipient if &%-bv%& is used; to test verification for a sender
3426 address, &%-bvs%& should be used.
3428 If the &%-v%& option is not set, the output consists of a single line for each
3429 address, stating whether it was verified or not, and giving a reason in the
3430 latter case. Without &%-v%&, generating more than one address by redirection
3431 causes verification to end successfully, without considering the generated
3432 addresses. However, if just one address is generated, processing continues,
3433 and the generated address must verify successfully for the overall verification
3434 to succeed.
3436 When &%-v%& is set, more details are given of how the address has been handled,
3437 and in the case of address redirection, all the generated addresses are also
3438 considered. Verification may succeed for some and fail for others.
3440 The
3441 .cindex "return code" "for &%-bv%&"
3442 return code is 2 if any address failed outright; it is 1 if no address
3443 failed outright but at least one could not be resolved for some reason. Return
3444 code 0 is given only when all addresses succeed.
3446 If any of the routers in the configuration makes any tests on the sender
3447 address of a message, you should use the &%-f%& option to set an appropriate
3448 sender when running &%-bv%& tests. Without it, the sender is assumed to be the
3449 calling user at the default qualifying domain.
3451 .vitem &%-bvs%&
3452 .oindex "&%-bvs%&"
3453 This option acts like &%-bv%&, but verifies the address as a sender rather
3454 than a recipient address. This affects any rewriting and qualification that
3455 might happen.
3457 .vitem &%-bw%&
3458 .oindex "&%-bw%&"
3459 .cindex "daemon"
3460 .cindex "inetd"
3461 .cindex "inetd" "wait mode"
3462 This option runs Exim as a daemon, awaiting incoming SMTP connections,
3463 similarly to the &%-bd%& option. All port specifications on the command-line
3464 and in the configuration file are ignored. Queue-running may not be specified.
3466 In this mode, Exim expects to be passed a socket as fd 0 (stdin) which is
3467 listening for connections. This permits the system to start up and have
3468 inetd (or equivalent) listen on the SMTP ports, starting an Exim daemon for
3469 each port only when the first connection is received.
3471 If the option is given as &%-bw%&<&'time'&> then the time is a timeout, after
3472 which the daemon will exit, which should cause inetd to listen once more.
3474 .vitem &%-C%&&~<&'filelist'&>
3475 .oindex "&%-C%&"
3476 .cindex "configuration file" "alternate"
3477 .cindex "CONFIGURE_FILE"
3478 .cindex "alternate configuration file"
3479 This option causes Exim to find the run time configuration file from the given
3480 list instead of from the list specified by the CONFIGURE_FILE
3481 compile-time setting. Usually, the list will consist of just a single file
3482 name, but it can be a colon-separated list of names. In this case, the first
3483 file that exists is used. Failure to open an existing file stops Exim from
3484 proceeding any further along the list, and an error is generated.
3486 When this option is used by a caller other than root, and the list is different
3487 from the compiled-in list, Exim gives up its root privilege immediately, and
3488 runs with the real and effective uid and gid set to those of the caller.
3489 However, if a TRUSTED_CONFIG_LIST file is defined in &_Local/Makefile_&, that
3490 file contains a list of full pathnames, one per line, for configuration files
3491 which are trusted. Root privilege is retained for any configuration file so
3492 listed, as long as the caller is the Exim user (or the user specified in the
3493 CONFIGURE_OWNER option, if any), and as long as the configuration file is
3494 not writeable by inappropriate users or groups.
3496 Leaving TRUSTED_CONFIG_LIST unset precludes the possibility of testing a
3497 configuration using &%-C%& right through message reception and delivery,
3498 even if the caller is root. The reception works, but by that time, Exim is
3499 running as the Exim user, so when it re-executes to regain privilege for the
3500 delivery, the use of &%-C%& causes privilege to be lost. However, root can
3501 test reception and delivery using two separate commands (one to put a message
3502 on the queue, using &%-odq%&, and another to do the delivery, using &%-M%&).
3504 If ALT_CONFIG_PREFIX is defined &_in Local/Makefile_&, it specifies a
3505 prefix string with which any file named in a &%-C%& command line option
3506 must start. In addition, the file name must not contain the sequence &`/../`&.
3507 However, if the value of the &%-C%& option is identical to the value of
3508 CONFIGURE_FILE in &_Local/Makefile_&, Exim ignores &%-C%& and proceeds as
3509 usual. There is no default setting for ALT_CONFIG_PREFIX; when it is
3510 unset, any file name can be used with &%-C%&.
3512 ALT_CONFIG_PREFIX can be used to confine alternative configuration files
3513 to a directory to which only root has access. This prevents someone who has
3514 broken into the Exim account from running a privileged Exim with an arbitrary
3515 configuration file.
3517 The &%-C%& facility is useful for ensuring that configuration files are
3518 syntactically correct, but cannot be used for test deliveries, unless the
3519 caller is privileged, or unless it is an exotic configuration that does not
3520 require privilege. No check is made on the owner or group of the files
3521 specified by this option.
3524 .vitem &%-D%&<&'macro'&>=<&'value'&>
3525 .oindex "&%-D%&"
3526 .cindex "macro" "setting on command line"
3527 This option can be used to override macro definitions in the configuration file
3528 (see section &<<SECTmacrodefs>>&). However, like &%-C%&, if it is used by an
3529 unprivileged caller, it causes Exim to give up its root privilege.
3530 If DISABLE_D_OPTION is defined in &_Local/Makefile_&, the use of &%-D%& is
3531 completely disabled, and its use causes an immediate error exit.
3533 If WHITELIST_D_MACROS is defined in &_Local/Makefile_& then it should be a
3534 colon-separated list of macros which are considered safe and, if &%-D%& only
3535 supplies macros from this list, and the values are acceptable, then Exim will
3536 not give up root privilege if the caller is root, the Exim run-time user, or
3537 the CONFIGURE_OWNER, if set. This is a transition mechanism and is expected
3538 to be removed in the future. Acceptable values for the macros satisfy the
3539 regexp: &`^[A-Za-z0-9_/.-]*$`&
3541 The entire option (including equals sign if present) must all be within one
3542 command line item. &%-D%& can be used to set the value of a macro to the empty
3543 string, in which case the equals sign is optional. These two commands are
3544 synonymous:
3545 .code
3546 exim -DABC ...
3547 exim -DABC= ...
3548 .endd
3549 To include spaces in a macro definition item, quotes must be used. If you use
3550 quotes, spaces are permitted around the macro name and the equals sign. For
3551 example:
3552 .code
3553 exim '-D ABC = something' ...
3554 .endd
3555 &%-D%& may be repeated up to 10 times on a command line.
3558 .vitem &%-d%&<&'debug&~options'&>
3559 .oindex "&%-d%&"
3560 .cindex "debugging" "list of selectors"
3561 .cindex "debugging" "&%-d%& option"
3562 This option causes debugging information to be written to the standard
3563 error stream. It is restricted to admin users because debugging output may show
3564 database queries that contain password information. Also, the details of users'
3565 filter files should be protected. If a non-admin user uses &%-d%&, Exim
3566 writes an error message to the standard error stream and exits with a non-zero
3567 return code.
3569 When &%-d%& is used, &%-v%& is assumed. If &%-d%& is given on its own, a lot of
3570 standard debugging data is output. This can be reduced, or increased to include
3571 some more rarely needed information, by directly following &%-d%& with a string
3572 made up of names preceded by plus or minus characters. These add or remove sets
3573 of debugging data, respectively. For example, &%-d+filter%& adds filter
3574 debugging, whereas &%-d-all+filter%& selects only filter debugging. Note that
3575 no spaces are allowed in the debug setting. The available debugging categories
3576 are:
3577 .display
3578 &`acl `& ACL interpretation
3579 &`auth `& authenticators
3580 &`deliver `& general delivery logic
3581 &`dns `& DNS lookups (see also resolver)
3582 &`dnsbl `& DNS black list (aka RBL) code
3583 &`exec `& arguments for &[execv()]& calls
3584 &`expand `& detailed debugging for string expansions
3585 &`filter `& filter handling
3586 &`hints_lookup `& hints data lookups
3587 &`host_lookup `& all types of name-to-IP address handling
3588 &`ident `& ident lookup
3589 &`interface `& lists of local interfaces
3590 &`lists `& matching things in lists
3591 &`load `& system load checks
3592 &`local_scan `& can be used by &[local_scan()]& (see chapter &&&
3593 &<<CHAPlocalscan>>&)
3594 &`lookup `& general lookup code and all lookups
3595 &`memory `& memory handling
3596 &`pid `& add pid to debug output lines
3597 &`process_info `& setting info for the process log
3598 &`queue_run `& queue runs
3599 &`receive `& general message reception logic
3600 &`resolver `& turn on the DNS resolver's debugging output
3601 &`retry `& retry handling
3602 &`rewrite `& address rewriting
3603 &`route `& address routing
3604 &`timestamp `& add timestamp to debug output lines
3605 &`tls `& TLS logic
3606 &`transport `& transports
3607 &`uid `& changes of uid/gid and looking up uid/gid
3608 &`verify `& address verification logic
3609 &`all `& almost all of the above (see below), and also &%-v%&
3610 .endd
3611 The &`all`& option excludes &`memory`& when used as &`+all`&, but includes it
3612 for &`-all`&. The reason for this is that &`+all`& is something that people
3613 tend to use when generating debug output for Exim maintainers. If &`+memory`&
3614 is included, an awful lot of output that is very rarely of interest is
3615 generated, so it now has to be explicitly requested. However, &`-all`& does
3616 turn everything off.
3618 .cindex "resolver, debugging output"
3619 .cindex "DNS resolver, debugging output"
3620 The &`resolver`& option produces output only if the DNS resolver was compiled
3621 with DEBUG enabled. This is not the case in some operating systems. Also,
3622 unfortunately, debugging output from the DNS resolver is written to stdout
3623 rather than stderr.
3625 The default (&%-d%& with no argument) omits &`expand`&, &`filter`&,
3626 &`interface`&, &`load`&, &`memory`&, &`pid`&, &`resolver`&, and &`timestamp`&.
3627 However, the &`pid`& selector is forced when debugging is turned on for a
3628 daemon, which then passes it on to any re-executed Exims. Exim also
3629 automatically adds the pid to debug lines when several remote deliveries are
3630 run in parallel.
3632 The &`timestamp`& selector causes the current time to be inserted at the start
3633 of all debug output lines. This can be useful when trying to track down delays
3634 in processing.
3636 If the &%debug_print%& option is set in any driver, it produces output whenever
3637 any debugging is selected, or if &%-v%& is used.
3639 .vitem &%-dd%&<&'debug&~options'&>
3640 .oindex "&%-dd%&"
3641 This option behaves exactly like &%-d%& except when used on a command that
3642 starts a daemon process. In that case, debugging is turned off for the
3643 subprocesses that the daemon creates. Thus, it is useful for monitoring the
3644 behaviour of the daemon without creating as much output as full debugging does.
3646 .vitem &%-dropcr%&
3647 .oindex "&%-dropcr%&"
3648 This is an obsolete option that is now a no-op. It used to affect the way Exim
3649 handled CR and LF characters in incoming messages. What happens now is
3650 described in section &<<SECTlineendings>>&.
3652 .vitem &%-E%&
3653 .oindex "&%-E%&"
3654 .cindex "bounce message" "generating"
3655 This option specifies that an incoming message is a locally-generated delivery
3656 failure report. It is used internally by Exim when handling delivery failures
3657 and is not intended for external use. Its only effect is to stop Exim
3658 generating certain messages to the postmaster, as otherwise message cascades
3659 could occur in some situations. As part of the same option, a message id may
3660 follow the characters &%-E%&. If it does, the log entry for the receipt of the
3661 new message contains the id, following &"R="&, as a cross-reference.
3663 .vitem &%-e%&&'x'&
3664 .oindex "&%-e%&&'x'&"
3665 There are a number of Sendmail options starting with &%-oe%& which seem to be
3666 called by various programs without the leading &%o%& in the option. For
3667 example, the &%vacation%& program uses &%-eq%&. Exim treats all options of the
3668 form &%-e%&&'x'& as synonymous with the corresponding &%-oe%&&'x'& options.
3670 .vitem &%-F%&&~<&'string'&>
3671 .oindex "&%-F%&"
3672 .cindex "sender" "name"
3673 .cindex "name" "of sender"
3674 This option sets the sender's full name for use when a locally-generated
3675 message is being accepted. In the absence of this option, the user's &'gecos'&
3676 entry from the password data is used. As users are generally permitted to alter
3677 their &'gecos'& entries, no security considerations are involved. White space
3678 between &%-F%& and the <&'string'&> is optional.
3680 .vitem &%-f%&&~<&'address'&>
3681 .oindex "&%-f%&"
3682 .cindex "sender" "address"
3683 .cindex "address" "sender"
3684 .cindex "trusted users"
3685 .cindex "envelope sender"
3686 .cindex "user" "trusted"
3687 This option sets the address of the envelope sender of a locally-generated
3688 message (also known as the return path). The option can normally be used only
3689 by a trusted user, but &%untrusted_set_sender%& can be set to allow untrusted
3690 users to use it.
3692 Processes running as root or the Exim user are always trusted. Other
3693 trusted users are defined by the &%trusted_users%& or &%trusted_groups%&
3694 options. In the absence of &%-f%&, or if the caller is not trusted, the sender
3695 of a local message is set to the caller's login name at the default qualify
3696 domain.
3698 There is one exception to the restriction on the use of &%-f%&: an empty sender
3699 can be specified by any user, trusted or not, to create a message that can
3700 never provoke a bounce. An empty sender can be specified either as an empty
3701 string, or as a pair of angle brackets with nothing between them, as in these
3702 examples of shell commands:
3703 .code
3704 exim -f '<>' user@domain
3705 exim -f "" user@domain
3706 .endd
3707 In addition, the use of &%-f%& is not restricted when testing a filter file
3708 with &%-bf%& or when testing or verifying addresses using the &%-bt%& or
3709 &%-bv%& options.
3711 Allowing untrusted users to change the sender address does not of itself make
3712 it possible to send anonymous mail. Exim still checks that the &'From:'& header
3713 refers to the local user, and if it does not, it adds a &'Sender:'& header,
3714 though this can be overridden by setting &%no_local_from_check%&.
3716 White
3717 .cindex "&""From""& line"
3718 space between &%-f%& and the <&'address'&> is optional (that is, they can be
3719 given as two arguments or one combined argument). The sender of a
3720 locally-generated message can also be set (when permitted) by an initial
3721 &"From&~"& line in the message &-- see the description of &%-bm%& above &-- but
3722 if &%-f%& is also present, it overrides &"From&~"&.
3724 .vitem &%-G%&
3725 .oindex "&%-G%&"
3726 .cindex "submission fixups, suppressing (command-line)"
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.
3738 .vitem &%-h%&&~<&'number'&>
3739 .oindex "&%-h%&"
3740 .cindex "Sendmail compatibility" "&%-h%& option ignored"
3741 This option is accepted for compatibility with Sendmail, but has no effect. (In
3742 Sendmail it overrides the &"hop count"& obtained by counting &'Received:'&
3743 headers.)
3745 .vitem &%-i%&
3746 .oindex "&%-i%&"
3747 .cindex "Solaris" "&'mail'& command"
3748 .cindex "dot" "in incoming non-SMTP message"
3749 This option, which has the same effect as &%-oi%&, specifies that a dot on a
3750 line by itself should not terminate an incoming, non-SMTP message. I can find
3751 no documentation for this option in Solaris 2.4 Sendmail, but the &'mailx'&
3752 command in Solaris 2.4 uses it. See also &%-ti%&.
3754 .vitem &%-L%&&~<&'tag'&>
3755 .oindex "&%-L%&"
3756 .cindex "syslog" "process name; set with flag"
3757 This option is equivalent to setting &%syslog_processname%& in the config
3758 file and setting &%log_file_path%& to &`syslog`&.
3759 Its use is restricted to administrators. The configuration file has to be
3760 read and parsed, to determine access rights, before this is set and takes
3761 effect, so early configuration file errors will not honour this flag.
3763 The tag should not be longer than 32 characters.
3765 .vitem &%-M%&&~<&'message&~id'&>&~<&'message&~id'&>&~...
3766 .oindex "&%-M%&"
3767 .cindex "forcing delivery"
3768 .cindex "delivery" "forcing attempt"
3769 .cindex "frozen messages" "forcing delivery"
3770 This option requests Exim to run a delivery attempt on each message in turn. If
3771 any of the messages are frozen, they are automatically thawed before the
3772 delivery attempt. The settings of &%queue_domains%&, &%queue_smtp_domains%&,
3773 and &%hold_domains%& are ignored.
3775 Retry
3776 .cindex "hints database" "overriding retry hints"
3777 hints for any of the addresses are overridden &-- Exim tries to deliver even if
3778 the normal retry time has not yet been reached. This option requires the caller
3779 to be an admin user. However, there is an option called &%prod_requires_admin%&
3780 which can be set false to relax this restriction (and also the same requirement
3781 for the &%-q%&, &%-R%&, and &%-S%& options).
3783 The deliveries happen synchronously, that is, the original Exim process does
3784 not terminate until all the delivery attempts have finished. No output is
3785 produced unless there is a serious error. If you want to see what is happening,
3786 use the &%-v%& option as well, or inspect Exim's main log.
3788 .vitem &%-Mar%&&~<&'message&~id'&>&~<&'address'&>&~<&'address'&>&~...
3789 .oindex "&%-Mar%&"
3790 .cindex "message" "adding recipients"
3791 .cindex "recipient" "adding"
3792 This option requests Exim to add the addresses to the list of recipients of the
3793 message (&"ar"& for &"add recipients"&). The first argument must be a message
3794 id, and the remaining ones must be email addresses. However, if the message is
3795 active (in the middle of a delivery attempt), it is not altered. This option
3796 can be used only by an admin user.
3798 .vitem "&%-MC%&&~<&'transport'&>&~<&'hostname'&>&~<&'sequence&~number'&>&&&
3799 &~<&'message&~id'&>"
3800 .oindex "&%-MC%&"
3801 .cindex "SMTP" "passed connection"
3802 .cindex "SMTP" "multiple deliveries"
3803 .cindex "multiple SMTP deliveries"
3804 This option is not intended for use by external callers. It is used internally
3805 by Exim to invoke another instance of itself to deliver a waiting message using
3806 an existing SMTP connection, which is passed as the standard input. Details are
3807 given in chapter &<<CHAPSMTP>>&. This must be the final option, and the caller
3808 must be root or the Exim user in order to use it.
3810 .vitem &%-MCA%&
3811 .oindex "&%-MCA%&"
3812 This option is not intended for use by external callers. It is used internally
3813 by Exim in conjunction with the &%-MC%& option. It signifies that the
3814 connection to the remote host has been authenticated.
3816 .new
3817 .vitem &%-MCD%&
3818 .oindex "&%-MCD%&"
3819 This option is not intended for use by external callers. It is used internally
3820 by Exim in conjunction with the &%-MC%& option. It signifies that the
3821 remote host supports the ESMTP &_DSN_& extension.
3822 .wen
3824 .vitem &%-MCP%&
3825 .oindex "&%-MCP%&"
3826 This option is not intended for use by external callers. It is used internally
3827 by Exim in conjunction with the &%-MC%& option. It signifies that the server to
3828 which Exim is connected supports pipelining.
3830 .vitem &%-MCQ%&&~<&'process&~id'&>&~<&'pipe&~fd'&>
3831 .oindex "&%-MCQ%&"
3832 This option is not intended for use by external callers. It is used internally
3833 by Exim in conjunction with the &%-MC%& option when the original delivery was
3834 started by a queue runner. It passes on the process id of the queue runner,
3835 together with the file descriptor number of an open pipe. Closure of the pipe
3836 signals the final completion of the sequence of processes that are passing
3837 messages through the same SMTP connection.
3839 .vitem &%-MCS%&
3840 .oindex "&%-MCS%&"
3841 This option is not intended for use by external callers. It is used internally
3842 by Exim in conjunction with the &%-MC%& option, and passes on the fact that the
3843 SMTP SIZE option should be used on messages delivered down the existing
3844 connection.
3846 .vitem &%-MCT%&
3847 .oindex "&%-MCT%&"
3848 This option is not intended for use by external callers. It is used internally
3849 by Exim in conjunction with the &%-MC%& option, and passes on the fact that the
3850 host to which Exim is connected supports TLS encryption.
3852 .vitem &%-Mc%&&~<&'message&~id'&>&~<&'message&~id'&>&~...
3853 .oindex "&%-Mc%&"
3854 .cindex "hints database" "not overridden by &%-Mc%&"
3855 .cindex "delivery" "manually started &-- not forced"
3856 This option requests Exim to run a delivery attempt on each message in turn,
3857 but unlike the &%-M%& option, it does check for retry hints, and respects any
3858 that are found. This option is not very useful to external callers. It is
3859 provided mainly for internal use by Exim when it needs to re-invoke itself in
3860 order to regain root privilege for a delivery (see chapter &<<CHAPsecurity>>&).
3861 However, &%-Mc%& can be useful when testing, in order to run a delivery that
3862 respects retry times and other options such as &%hold_domains%& that are
3863 overridden when &%-M%& is used. Such a delivery does not count as a queue run.
3864 If you want to run a specific delivery as if in a queue run, you should use
3865 &%-q%& with a message id argument. A distinction between queue run deliveries
3866 and other deliveries is made in one or two places.
3868 .vitem &%-Mes%&&~<&'message&~id'&>&~<&'address'&>
3869 .oindex "&%-Mes%&"
3870 .cindex "message" "changing sender"
3871 .cindex "sender" "changing"
3872 This option requests Exim to change the sender address in the message to the
3873 given address, which must be a fully qualified address or &"<>"& (&"es"& for
3874 &"edit sender"&). There must be exactly two arguments. The first argument must
3875 be a message id, and the second one an email address. However, if the message
3876 is active (in the middle of a delivery attempt), its status is not altered.
3877 This option can be used only by an admin user.
3879 .vitem &%-Mf%&&~<&'message&~id'&>&~<&'message&~id'&>&~...
3880 .oindex "&%-Mf%&"
3881 .cindex "freezing messages"
3882 .cindex "message" "manually freezing"
3883 This option requests Exim to mark each listed message as &"frozen"&. This
3884 prevents any delivery attempts taking place until the message is &"thawed"&,
3885 either manually or as a result of the &%auto_thaw%& configuration option.
3886 However, if any of the messages are active (in the middle of a delivery
3887 attempt), their status is not altered. This option can be used only by an admin
3888 user.
3890 .vitem &%-Mg%&&~<&'message&~id'&>&~<&'message&~id'&>&~...
3891 .oindex "&%-Mg%&"
3892 .cindex "giving up on messages"
3893 .cindex "message" "abandoning delivery attempts"
3894 .cindex "delivery" "abandoning further attempts"
3895 This option requests Exim to give up trying to deliver the listed messages,
3896 including any that are frozen. However, if any of the messages are active,
3897 their status is not altered. For non-bounce messages, a delivery error message
3898 is sent to the sender, containing the text &"cancelled by administrator"&.
3899 Bounce messages are just discarded. This option can be used only by an admin
3900 user.
3902 .vitem &%-Mmad%&&~<&'message&~id'&>&~<&'message&~id'&>&~...
3903 .oindex "&%-Mmad%&"
3904 .cindex "delivery" "cancelling all"
3905 This option requests Exim to mark all the recipient addresses in the messages
3906 as already delivered (&"mad"& for &"mark all delivered"&). However, if any
3907 message is active (in the middle of a delivery attempt), its status is not
3908 altered. This option can be used only by an admin user.
3910 .vitem &%-Mmd%&&~<&'message&~id'&>&~<&'address'&>&~<&'address'&>&~...
3911 .oindex "&%-Mmd%&"
3912 .cindex "delivery" "cancelling by address"
3913 .cindex "recipient" "removing"
3914 .cindex "removing recipients"
3915 This option requests Exim to mark the given addresses as already delivered
3916 (&"md"& for &"mark delivered"&). The first argument must be a message id, and
3917 the remaining ones must be email addresses. These are matched to recipient
3918 addresses in the message in a case-sensitive manner. If the message is active
3919 (in the middle of a delivery attempt), its status is not altered. This option
3920 can be used only by an admin user.
3922 .vitem &%-Mrm%&&~<&'message&~id'&>&~<&'message&~id'&>&~...
3923 .oindex "&%-Mrm%&"
3924 .cindex "removing messages"
3925 .cindex "abandoning mail"
3926 .cindex "message" "manually discarding"
3927 This option requests Exim to remove the given messages from the queue. No
3928 bounce messages are sent; each message is simply forgotten. However, if any of
3929 the messages are active, their status is not altered. This option can be used
3930 only by an admin user or by the user who originally caused the message to be
3931 placed on the queue.
3933 .vitem &%-Mset%&&~<&'message&~id'&>
3934 .oindex "&%-Mset%&
3935 .cindex "testing" "string expansion"
3936 .cindex "expansion" "testing"
3937 This option is useful only in conjunction with &%-be%& (that is, when testing
3938 string expansions). Exim loads the given message from its spool before doing
3939 the test expansions, thus setting message-specific variables such as
3940 &$message_size$& and the header variables. The &$recipients$& variable is made
3941 available. This feature is provided to make it easier to test expansions that
3942 make use of these variables. However, this option can be used only by an admin
3943 user. See also &%-bem%&.
3945 .vitem &%-Mt%&&~<&'message&~id'&>&~<&'message&~id'&>&~...
3946 .oindex "&%-Mt%&"
3947 .cindex "thawing messages"
3948 .cindex "unfreezing messages"
3949 .cindex "frozen messages" "thawing"
3950 .cindex "message" "thawing frozen"
3951 This option requests Exim to &"thaw"& any of the listed messages that are
3952 &"frozen"&, so that delivery attempts can resume. However, if any of the
3953 messages are active, their status is not altered. This option can be used only
3954 by an admin user.
3956 .vitem &%-Mvb%&&~<&'message&~id'&>
3957 .oindex "&%-Mvb%&"
3958 .cindex "listing" "message body"
3959 .cindex "message" "listing body of"
3960 This option causes the contents of the message body (-D) spool file to be
3961 written to the standard output. This option can be used only by an admin user.
3963 .vitem &%-Mvc%&&~<&'message&~id'&>
3964 .oindex "&%-Mvc%&"
3965 .cindex "message" "listing in RFC 2822 format"
3966 .cindex "listing" "message in RFC 2822 format"
3967 This option causes a copy of the complete message (header lines plus body) to
3968 be written to the standard output in RFC 2822 format. This option can be used
3969 only by an admin user.
3971 .vitem &%-Mvh%&&~<&'message&~id'&>
3972 .oindex "&%-Mvh%&"
3973 .cindex "listing" "message headers"
3974 .cindex "header lines" "listing"
3975 .cindex "message" "listing header lines"
3976 This option causes the contents of the message headers (-H) spool file to be
3977 written to the standard output. This option can be used only by an admin user.
3979 .vitem &%-Mvl%&&~<&'message&~id'&>
3980 .oindex "&%-Mvl%&"
3981 .cindex "listing" "message log"
3982 .cindex "message" "listing message log"
3983 This option causes the contents of the message log spool file to be written to
3984 the standard output. This option can be used only by an admin user.
3986 .vitem &%-m%&
3987 .oindex "&%-m%&"
3988 This is apparently a synonym for &%-om%& that is accepted by Sendmail, so Exim
3989 treats it that way too.
3991 .vitem &%-N%&
3992 .oindex "&%-N%&"
3993 .cindex "debugging" "&%-N%& option"
3994 .cindex "debugging" "suppressing delivery"
3995 This is a debugging option that inhibits delivery of a message at the transport
3996 level. It implies &%-v%&. Exim goes through many of the motions of delivery &--
3997 it just doesn't actually transport the message, but instead behaves as if it
3998 had successfully done so. However, it does not make any updates to the retry
3999 database, and the log entries for deliveries are flagged with &"*>"& rather
4000 than &"=>"&.
4002 Because &%-N%& discards any message to which it applies, only root or the Exim
4003 user are allowed to use it with &