Drop server_realm from heimdal_gssapi
[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. Remember that
45 . the <bookinfo> element must also be updated for each new edition.
46 . /////////////////////////////////////////////////////////////////////////////
48 .set previousversion "4.75"
49 .set version "4.77"
51 .set ACL "access control lists (ACLs)"
52 .set I "&nbsp;&nbsp;&nbsp;&nbsp;"
55 . /////////////////////////////////////////////////////////////////////////////
56 . Additional xfpt markup used by this document, over and above the default
57 . provided in the xfpt library.
58 . /////////////////////////////////////////////////////////////////////////////
60 . --- Override the &$ flag to automatically insert a $ with the variable name
62 .flag &$ $& "<varname>$" "</varname>"
64 . --- Short flags for daggers in option headings. They will always be inside
65 . --- an italic string, but we want the daggers to be roman.
67 .flag &!! "</emphasis>&dagger;<emphasis>"
68 .flag &!? "</emphasis>&Dagger;<emphasis>"
70 . --- A macro for an Exim option definition heading, generating a one-line
71 . --- table with four columns. For cases when the option name is given with
72 . --- a space, so that it can be split, a fifth argument is used for the
73 . --- index entry.
75 .macro option
76 .arg 5
77 .oindex "&%$5%&"
78 .endarg
79 .arg -5
80 .oindex "&%$1%&"
81 .endarg
82 .itable all 0 0 4 8* left 6* center 6* center 6* right
83 .row "&%$1%&" "Use: &'$2'&" "Type: &'$3'&" "Default: &'$4'&"
84 .endtable
85 .endmacro
87 . --- A macro for the common 2-column tables. The width of the first column
88 . --- is suitable for the many tables at the start of the main options chapter;
89 . --- the small number of other 2-column tables override it.
91 .macro table2 196pt 254pt
92 .itable none 0 0 2 $1 left $2 left
93 .endmacro
95 . --- A macro that generates .row, but puts &I; at the start of the first
96 . --- argument, thus indenting it. Assume a minimum of two arguments, and
97 . --- allow up to four arguments, which is as many as we'll ever need.
99 .macro irow
100 .arg 4
101 .row "&I;$1" "$2" "$3" "$4"
102 .endarg
103 .arg -4
104 .arg 3
105 .row "&I;$1" "$2" "$3"
106 .endarg
107 .arg -3
108 .row "&I;$1" "$2"
109 .endarg
110 .endarg
111 .endmacro
113 . --- Macros for option, variable, and concept index entries. For a "range"
114 . --- style of entry, use .scindex for the start and .ecindex for the end. The
115 . --- first argument of .scindex and the only argument of .ecindex must be the
116 . --- ID that ties them together.
118 .macro cindex
119 &<indexterm role="concept">&
120 &<primary>&$1&</primary>&
121 .arg 2
122 &<secondary>&$2&</secondary>&
123 .endarg
124 &</indexterm>&
125 .endmacro
127 .macro scindex
128 &<indexterm role="concept" id="$1" class="startofrange">&
129 &<primary>&$2&</primary>&
130 .arg 3
131 &<secondary>&$3&</secondary>&
132 .endarg
133 &</indexterm>&
134 .endmacro
136 .macro ecindex
137 &<indexterm role="concept" startref="$1" class="endofrange"/>&
138 .endmacro
140 .macro oindex
141 &<indexterm role="option">&
142 &<primary>&$1&</primary>&
143 .arg 2
144 &<secondary>&$2&</secondary>&
145 .endarg
146 &</indexterm>&
147 .endmacro
149 .macro vindex
150 &<indexterm role="variable">&
151 &<primary>&$1&</primary>&
152 .arg 2
153 &<secondary>&$2&</secondary>&
154 .endarg
155 &</indexterm>&
156 .endmacro
158 .macro index
159 .echo "** Don't use .index; use .cindex or .oindex or .vindex"
160 .endmacro
161 . ////////////////////////////////////////////////////////////////////////////
164 . ////////////////////////////////////////////////////////////////////////////
165 . The <bookinfo> element is removed from the XML before processing for Ascii
166 . output formats.
167 . ////////////////////////////////////////////////////////////////////////////
169 .literal xml
170 <bookinfo>
171 <title>Specification of the Exim Mail Transfer Agent</title>
172 <titleabbrev>The Exim MTA</titleabbrev>
173 <date>06 May 2011</date>
174 <author><firstname>Exim</firstname><surname>Maintainers</surname></author>
175 <authorinitials>EM</authorinitials>
176 <revhistory><revision>
177 <revnumber>4.77</revnumber>
178 <date>10 Oct 2011</date>
179 <authorinitials>EM</authorinitials>
180 </revision></revhistory>
181 <copyright><year>2011</year><holder>University of Cambridge</holder></copyright>
182 </bookinfo>
183 .literal off
186 . /////////////////////////////////////////////////////////////////////////////
187 . This chunk of literal XML implements index entries of the form "x, see y" and
188 . "x, see also y". However, the DocBook DTD doesn't allow <indexterm> entries
189 . at the top level, so we have to put the .chapter directive first.
190 . /////////////////////////////////////////////////////////////////////////////
192 .chapter "Introduction" "CHID1"
193 .literal xml
195 <indexterm role="variable">
196 <primary>$1, $2, etc.</primary>
197 <see><emphasis>numerical variables</emphasis></see>
198 </indexterm>
199 <indexterm role="concept">
200 <primary>address</primary>
201 <secondary>rewriting</secondary>
202 <see><emphasis>rewriting</emphasis></see>
203 </indexterm>
204 <indexterm role="concept">
205 <primary>Bounce Address Tag Validation</primary>
206 <see><emphasis>BATV</emphasis></see>
207 </indexterm>
208 <indexterm role="concept">
209 <primary>Client SMTP Authorization</primary>
210 <see><emphasis>CSA</emphasis></see>
211 </indexterm>
212 <indexterm role="concept">
213 <primary>CR character</primary>
214 <see><emphasis>carriage return</emphasis></see>
215 </indexterm>
216 <indexterm role="concept">
217 <primary>CRL</primary>
218 <see><emphasis>certificate revocation list</emphasis></see>
219 </indexterm>
220 <indexterm role="concept">
221 <primary>delivery</primary>
222 <secondary>failure report</secondary>
223 <see><emphasis>bounce message</emphasis></see>
224 </indexterm>
225 <indexterm role="concept">
226 <primary>dialup</primary>
227 <see><emphasis>intermittently connected hosts</emphasis></see>
228 </indexterm>
229 <indexterm role="concept">
230 <primary>exiscan</primary>
231 <see><emphasis>content scanning</emphasis></see>
232 </indexterm>
233 <indexterm role="concept">
234 <primary>failover</primary>
235 <see><emphasis>fallback</emphasis></see>
236 </indexterm>
237 <indexterm role="concept">
238 <primary>fallover</primary>
239 <see><emphasis>fallback</emphasis></see>
240 </indexterm>
241 <indexterm role="concept">
242 <primary>filter</primary>
243 <secondary>Sieve</secondary>
244 <see><emphasis>Sieve filter</emphasis></see>
245 </indexterm>
246 <indexterm role="concept">
247 <primary>ident</primary>
248 <see><emphasis>RFC 1413</emphasis></see>
249 </indexterm>
250 <indexterm role="concept">
251 <primary>LF character</primary>
252 <see><emphasis>linefeed</emphasis></see>
253 </indexterm>
254 <indexterm role="concept">
255 <primary>maximum</primary>
256 <seealso><emphasis>limit</emphasis></seealso>
257 </indexterm>
258 <indexterm role="concept">
259 <primary>monitor</primary>
260 <see><emphasis>Exim monitor</emphasis></see>
261 </indexterm>
262 <indexterm role="concept">
263 <primary>no_<emphasis>xxx</emphasis></primary>
264 <see>entry for xxx</see>
265 </indexterm>
266 <indexterm role="concept">
267 <primary>NUL</primary>
268 <see><emphasis>binary zero</emphasis></see>
269 </indexterm>
270 <indexterm role="concept">
271 <primary>passwd file</primary>
272 <see><emphasis>/etc/passwd</emphasis></see>
273 </indexterm>
274 <indexterm role="concept">
275 <primary>process id</primary>
276 <see><emphasis>pid</emphasis></see>
277 </indexterm>
278 <indexterm role="concept">
279 <primary>RBL</primary>
280 <see><emphasis>DNS list</emphasis></see>
281 </indexterm>
282 <indexterm role="concept">
283 <primary>redirection</primary>
284 <see><emphasis>address redirection</emphasis></see>
285 </indexterm>
286 <indexterm role="concept">
287 <primary>return path</primary>
288 <seealso><emphasis>envelope sender</emphasis></seealso>
289 </indexterm>
290 <indexterm role="concept">
291 <primary>scanning</primary>
292 <see><emphasis>content scanning</emphasis></see>
293 </indexterm>
294 <indexterm role="concept">
295 <primary>SSL</primary>
296 <see><emphasis>TLS</emphasis></see>
297 </indexterm>
298 <indexterm role="concept">
299 <primary>string</primary>
300 <secondary>expansion</secondary>
301 <see><emphasis>expansion</emphasis></see>
302 </indexterm>
303 <indexterm role="concept">
304 <primary>top bit</primary>
305 <see><emphasis>8-bit characters</emphasis></see>
306 </indexterm>
307 <indexterm role="concept">
308 <primary>variables</primary>
309 <see><emphasis>expansion, variables</emphasis></see>
310 </indexterm>
311 <indexterm role="concept">
312 <primary>zero, binary</primary>
313 <see><emphasis>binary zero</emphasis></see>
314 </indexterm>
316 .literal off
319 . /////////////////////////////////////////////////////////////////////////////
320 . This is the real start of the first chapter. See the comment above as to why
321 . we can't have the .chapter line here.
322 . chapter "Introduction"
323 . /////////////////////////////////////////////////////////////////////////////
325 Exim is a mail transfer agent (MTA) for hosts that are running Unix or
326 Unix-like operating systems. It was designed on the assumption that it would be
327 run on hosts that are permanently connected to the Internet. However, it can be
328 used on intermittently connected hosts with suitable configuration adjustments.
330 Configuration files currently exist for the following operating systems: AIX,
331 BSD/OS (aka BSDI), Darwin (Mac OS X), DGUX, Dragonfly, FreeBSD, GNU/Hurd,
332 GNU/Linux, HI-OSF (Hitachi), HI-UX, HP-UX, IRIX, MIPS RISCOS, NetBSD, OpenBSD,
333 OpenUNIX, QNX, SCO, SCO SVR4.2 (aka UNIX-SV), Solaris (aka SunOS5), SunOS4,
334 Tru64-Unix (formerly Digital UNIX, formerly DEC-OSF1), Ultrix, and Unixware.
335 Some of these operating systems are no longer current and cannot easily be
336 tested, so the configuration files may no longer work in practice.
338 There are also configuration files for compiling Exim in the Cygwin environment
339 that can be installed on systems running Windows. However, this document does
340 not contain any information about running Exim in the Cygwin environment.
342 The terms and conditions for the use and distribution of Exim are contained in
343 the file &_NOTICE_&. Exim is distributed under the terms of the GNU General
344 Public Licence, a copy of which may be found in the file &_LICENCE_&.
346 The use, supply or promotion of Exim for the purpose of sending bulk,
347 unsolicited electronic mail is incompatible with the basic aims of the program,
348 which revolve around the free provision of a service that enhances the quality
349 of personal communications. The author of Exim regards indiscriminate
350 mass-mailing as an antisocial, irresponsible abuse of the Internet.
352 Exim owes a great deal to Smail 3 and its author, Ron Karr. Without the
353 experience of running and working on the Smail 3 code, I could never have
354 contemplated starting to write a new MTA. Many of the ideas and user interfaces
355 were originally taken from Smail 3, though the actual code of Exim is entirely
356 new, and has developed far beyond the initial concept.
358 Many people, both in Cambridge and around the world, have contributed to the
359 development and the testing of Exim, and to porting it to various operating
360 systems. I am grateful to them all. The distribution now contains a file called
361 &_ACKNOWLEDGMENTS_&, in which I have started recording the names of
362 contributors.
365 .section "Exim documentation" "SECID1"
366 . Keep this example change bar when updating the documentation!
368 .new
369 .cindex "documentation"
370 This edition of the Exim specification applies to version &version; of Exim.
371 Substantive changes from the &previousversion; edition are marked in some
372 renditions of the document; this paragraph is so marked if the rendition is
373 capable of showing a change indicator.
374 .wen
376 This document is very much a reference manual; it is not a tutorial. The reader
377 is expected to have some familiarity with the SMTP mail transfer protocol and
378 with general Unix system administration. Although there are some discussions
379 and examples in places, the information is mostly organized in a way that makes
380 it easy to look up, rather than in a natural order for sequential reading.
381 Furthermore, the manual aims to cover every aspect of Exim in detail, including
382 a number of rarely-used, special-purpose features that are unlikely to be of
383 very wide interest.
385 .cindex "books about Exim"
386 An &"easier"& discussion of Exim which provides more in-depth explanatory,
387 introductory, and tutorial material can be found in a book entitled &'The Exim
388 SMTP Mail Server'& (second edition, 2007), published by UIT Cambridge
389 (&url(http://www.uit.co.uk/exim-book/)).
391 This book also contains a chapter that gives a general introduction to SMTP and
392 Internet mail. Inevitably, however, the book is unlikely to be fully up-to-date
393 with the latest release of Exim. (Note that the earlier book about Exim,
394 published by O'Reilly, covers Exim 3, and many things have changed in Exim 4.)
396 .cindex "Debian" "information sources"
397 If you are using a Debian distribution of Exim, you will find information about
398 Debian-specific features in the file
399 &_/usr/share/doc/exim4-base/README.Debian_&.
400 The command &(man update-exim.conf)& is another source of Debian-specific
401 information.
403 .cindex "&_doc/NewStuff_&"
404 .cindex "&_doc/ChangeLog_&"
405 .cindex "change log"
406 As the program develops, there may be features in newer versions that have not
407 yet made it into this document, which is updated only when the most significant
408 digit of the fractional part of the version number changes. Specifications of
409 new features that are not yet in this manual are placed in the file
410 &_doc/NewStuff_& in the Exim distribution.
412 Some features may be classified as &"experimental"&. These may change
413 incompatibly while they are developing, or even be withdrawn. For this reason,
414 they are not documented in this manual. Information about experimental features
415 can be found in the file &_doc/experimental.txt_&.
417 All changes to the program (whether new features, bug fixes, or other kinds of
418 change) are noted briefly in the file called &_doc/ChangeLog_&.
420 .cindex "&_doc/spec.txt_&"
421 This specification itself is available as an ASCII file in &_doc/spec.txt_& so
422 that it can easily be searched with a text editor. Other files in the &_doc_&
423 directory are:
425 .table2 100pt
426 .row &_OptionLists.txt_& "list of all options in alphabetical order"
427 .row &_dbm.discuss.txt_& "discussion about DBM libraries"
428 .row &_exim.8_& "a man page of Exim's command line options"
429 .row &_experimental.txt_& "documentation of experimental features"
430 .row &_filter.txt_& "specification of the filter language"
431 .row &_Exim3.upgrade_& "upgrade notes from release 2 to release 3"
432 .row &_Exim4.upgrade_& "upgrade notes from release 3 to release 4"
433 .endtable
435 The main specification and the specification of the filtering language are also
436 available in other formats (HTML, PostScript, PDF, and Texinfo). Section
437 &<<SECTavail>>& below tells you how to get hold of these.
441 .section "FTP and web sites" "SECID2"
442 .cindex "web site"
443 .cindex "FTP site"
444 The primary site for Exim source distributions is currently the University of
445 Cambridge's FTP site, whose contents are described in &'Where to find the Exim
446 distribution'& below. In addition, there is a web site and an FTP site at
447 &%exim.org%&. These are now also hosted at the University of Cambridge. The
448 &%exim.org%& site was previously hosted for a number of years by Energis
449 Squared, formerly Planet Online Ltd, whose support I gratefully acknowledge.
451 .cindex "wiki"
452 .cindex "FAQ"
453 As well as Exim distribution tar files, the Exim web site contains a number of
454 differently formatted versions of the documentation. A recent addition to the
455 online information is the Exim wiki (&url(http://wiki.exim.org)),
456 which contains what used to be a separate FAQ, as well as various other
457 examples, tips, and know-how that have been contributed by Exim users.
459 .cindex Bugzilla
460 An Exim Bugzilla exists at &url(http://bugs.exim.org). You can use
461 this to report bugs, and also to add items to the wish list. Please search
462 first to check that you are not duplicating a previous entry.
466 .section "Mailing lists" "SECID3"
467 .cindex "mailing lists" "for Exim users"
468 The following Exim mailing lists exist:
470 .table2 140pt
471 .row &'exim-announce@exim.org'& "Moderated, low volume announcements list"
472 .row &'exim-users@exim.org'& "General discussion list"
473 .row &'exim-dev@exim.org'& "Discussion of bugs, enhancements, etc."
474 .row &'exim-cvs@exim.org'& "Automated commit messages from the VCS"
475 .endtable
477 You can subscribe to these lists, change your existing subscriptions, and view
478 or search the archives via the mailing lists link on the Exim home page.
479 .cindex "Debian" "mailing list for"
480 If you are using a Debian distribution of Exim, you may wish to subscribe to
481 the Debian-specific mailing list &'pkg-exim4-users@lists.alioth.debian.org'&
482 via this web page:
483 .display
484 &url(http://lists.alioth.debian.org/mailman/listinfo/pkg-exim4-users)
485 .endd
486 Please ask Debian-specific questions on this list and not on the general Exim
487 lists.
489 .section "Exim training" "SECID4"
490 .cindex "training courses"
491 Training courses in Cambridge (UK) used to be run annually by the author of
492 Exim, before he retired. At the time of writing, there are no plans to run
493 further Exim courses in Cambridge. However, if that changes, relevant
494 information will be posted at &url(http://www-tus.csx.cam.ac.uk/courses/exim/).
496 .section "Bug reports" "SECID5"
497 .cindex "bug reports"
498 .cindex "reporting bugs"
499 Reports of obvious bugs can be emailed to &'bugs@exim.org'& or reported
500 via the Bugzilla (&url(http://bugs.exim.org)). However, if you are unsure
501 whether some behaviour is a bug or not, the best thing to do is to post a
502 message to the &'exim-dev'& mailing list and have it discussed.
506 .section "Where to find the Exim distribution" "SECTavail"
507 .cindex "FTP site"
508 .cindex "distribution" "ftp site"
509 The master ftp site for the Exim distribution is
510 .display
511 &*ftp://ftp.csx.cam.ac.uk/pub/software/email/exim*&
512 .endd
513 This is mirrored by
514 .display
515 &*ftp://ftp.exim.org/pub/exim*&
516 .endd
517 The file references that follow are relative to the &_exim_& directories at
518 these sites. There are now quite a number of independent mirror sites around
519 the world. Those that I know about are listed in the file called &_Mirrors_&.
521 Within the &_exim_& directory there are subdirectories called &_exim3_& (for
522 previous Exim 3 distributions), &_exim4_& (for the latest Exim 4
523 distributions), and &_Testing_& for testing versions. In the &_exim4_&
524 subdirectory, the current release can always be found in files called
525 .display
526 &_exim-n.nn.tar.gz_&
527 &_exim-n.nn.tar.bz2_&
528 .endd
529 where &'n.nn'& is the highest such version number in the directory. The two
530 files contain identical data; the only difference is the type of compression.
531 The &_.bz2_& file is usually a lot smaller than the &_.gz_& file.
533 .cindex "distribution" "signing details"
534 .cindex "distribution" "public key"
535 .cindex "public key for signed distribution"
536 The distributions are currently signed with Nigel Metheringham's GPG key. The
537 corresponding public key is available from a number of keyservers, and there is
538 also a copy in the file &_nigel-pubkey.asc_&. The signatures for the tar bundles are
539 in:
540 .display
541 &_exim-n.nn.tar.gz.asc_&
542 &_exim-n.nn.tar.bz2.asc_&
543 .endd
544 For each released version, the log of changes is made separately available in a
545 separate file in the directory &_ChangeLogs_& so that it is possible to
546 find out what has changed without having to download the entire distribution.
548 .cindex "documentation" "available formats"
549 The main distribution contains ASCII versions of this specification and other
550 documentation; other formats of the documents are available in separate files
551 inside the &_exim4_& directory of the FTP site:
552 .display
553 &_exim-html-n.nn.tar.gz_&
554 &_exim-pdf-n.nn.tar.gz_&
555 &_exim-postscript-n.nn.tar.gz_&
556 &_exim-texinfo-n.nn.tar.gz_&
557 .endd
558 These tar files contain only the &_doc_& directory, not the complete
559 distribution, and are also available in &_.bz2_& as well as &_.gz_& forms.
562 .section "Limitations" "SECID6"
563 .ilist
564 .cindex "limitations of Exim"
565 .cindex "bang paths" "not handled by Exim"
566 Exim is designed for use as an Internet MTA, and therefore handles addresses in
567 RFC 2822 domain format only. It cannot handle UUCP &"bang paths"&, though
568 simple two-component bang paths can be converted by a straightforward rewriting
569 configuration. This restriction does not prevent Exim from being interfaced to
570 UUCP as a transport mechanism, provided that domain addresses are used.
571 .next
572 .cindex "domainless addresses"
573 .cindex "address" "without domain"
574 Exim insists that every address it handles has a domain attached. For incoming
575 local messages, domainless addresses are automatically qualified with a
576 configured domain value. Configuration options specify from which remote
577 systems unqualified addresses are acceptable. These are then qualified on
578 arrival.
579 .next
580 .cindex "transport" "external"
581 .cindex "external transports"
582 The only external transport mechanisms that are currently implemented are SMTP
583 and LMTP over a TCP/IP network (including support for IPv6). However, a pipe
584 transport is available, and there are facilities for writing messages to files
585 and pipes, optionally in &'batched SMTP'& format; these facilities can be used
586 to send messages to other transport mechanisms such as UUCP, provided they can
587 handle domain-style addresses. Batched SMTP input is also catered for.
588 .next
589 Exim is not designed for storing mail for dial-in hosts. When the volumes of
590 such mail are large, it is better to get the messages &"delivered"& into files
591 (that is, off Exim's queue) and subsequently passed on to the dial-in hosts by
592 other means.
593 .next
594 Although Exim does have basic facilities for scanning incoming messages, these
595 are not comprehensive enough to do full virus or spam scanning. Such operations
596 are best carried out using additional specialized software packages. If you
597 compile Exim with the content-scanning extension, straightforward interfaces to
598 a number of common scanners are provided.
599 .endlist
602 .section "Run time configuration" "SECID7"
603 Exim's run time configuration is held in a single text file that is divided
604 into a number of sections. The entries in this file consist of keywords and
605 values, in the style of Smail 3 configuration files. A default configuration
606 file which is suitable for simple online installations is provided in the
607 distribution, and is described in chapter &<<CHAPdefconfil>>& below.
610 .section "Calling interface" "SECID8"
611 .cindex "Sendmail compatibility" "command line interface"
612 Like many MTAs, Exim has adopted the Sendmail command line interface so that it
613 can be a straight replacement for &_/usr/lib/sendmail_& or
614 &_/usr/sbin/sendmail_& when sending mail, but you do not need to know anything
615 about Sendmail in order to run Exim. For actions other than sending messages,
616 Sendmail-compatible options also exist, but those that produce output (for
617 example, &%-bp%&, which lists the messages on the queue) do so in Exim's own
618 format. There are also some additional options that are compatible with Smail
619 3, and some further options that are new to Exim. Chapter &<<CHAPcommandline>>&
620 documents all Exim's command line options. This information is automatically
621 made into the man page that forms part of the Exim distribution.
623 Control of messages on the queue can be done via certain privileged command
624 line options. There is also an optional monitor program called &'eximon'&,
625 which displays current information in an X window, and which contains a menu
626 interface to Exim's command line administration options.
630 .section "Terminology" "SECID9"
631 .cindex "terminology definitions"
632 .cindex "body of message" "definition of"
633 The &'body'& of a message is the actual data that the sender wants to transmit.
634 It is the last part of a message, and is separated from the &'header'& (see
635 below) by a blank line.
637 .cindex "bounce message" "definition of"
638 When a message cannot be delivered, it is normally returned to the sender in a
639 delivery failure message or a &"non-delivery report"& (NDR). The term
640 &'bounce'& is commonly used for this action, and the error reports are often
641 called &'bounce messages'&. This is a convenient shorthand for &"delivery
642 failure error report"&. Such messages have an empty sender address in the
643 message's &'envelope'& (see below) to ensure that they cannot themselves give
644 rise to further bounce messages.
646 The term &'default'& appears frequently in this manual. It is used to qualify a
647 value which is used in the absence of any setting in the configuration. It may
648 also qualify an action which is taken unless a configuration setting specifies
649 otherwise.
651 The term &'defer'& is used when the delivery of a message to a specific
652 destination cannot immediately take place for some reason (a remote host may be
653 down, or a user's local mailbox may be full). Such deliveries are &'deferred'&
654 until a later time.
656 The word &'domain'& is sometimes used to mean all but the first component of a
657 host's name. It is &'not'& used in that sense here, where it normally refers to
658 the part of an email address following the @ sign.
660 .cindex "envelope, definition of"
661 .cindex "sender" "definition of"
662 A message in transit has an associated &'envelope'&, as well as a header and a
663 body. The envelope contains a sender address (to which bounce messages should
664 be delivered), and any number of recipient addresses. References to the
665 sender or the recipients of a message usually mean the addresses in the
666 envelope. An MTA uses these addresses for delivery, and for returning bounce
667 messages, not the addresses that appear in the header lines.
669 .cindex "message" "header, definition of"
670 .cindex "header section" "definition of"
671 The &'header'& of a message is the first part of a message's text, consisting
672 of a number of lines, each of which has a name such as &'From:'&, &'To:'&,
673 &'Subject:'&, etc. Long header lines can be split over several text lines by
674 indenting the continuations. The header is separated from the body by a blank
675 line.
677 .cindex "local part" "definition of"
678 .cindex "domain" "definition of"
679 The term &'local part'&, which is taken from RFC 2822, is used to refer to that
680 part of an email address that precedes the @ sign. The part that follows the
681 @ sign is called the &'domain'& or &'mail domain'&.
683 .cindex "local delivery" "definition of"
684 .cindex "remote delivery, definition of"
685 The terms &'local delivery'& and &'remote delivery'& are used to distinguish
686 delivery to a file or a pipe on the local host from delivery by SMTP over
687 TCP/IP to another host. As far as Exim is concerned, all hosts other than the
688 host it is running on are &'remote'&.
690 .cindex "return path" "definition of"
691 &'Return path'& is another name that is used for the sender address in a
692 message's envelope.
694 .cindex "queue" "definition of"
695 The term &'queue'& is used to refer to the set of messages awaiting delivery,
696 because this term is in widespread use in the context of MTAs. However, in
697 Exim's case the reality is more like a pool than a queue, because there is
698 normally no ordering of waiting messages.
700 .cindex "queue runner" "definition of"
701 The term &'queue runner'& is used to describe a process that scans the queue
702 and attempts to deliver those messages whose retry times have come. This term
703 is used by other MTAs, and also relates to the command &%runq%&, but in Exim
704 the waiting messages are normally processed in an unpredictable order.
706 .cindex "spool directory" "definition of"
707 The term &'spool directory'& is used for a directory in which Exim keeps the
708 messages on its queue &-- that is, those that it is in the process of
709 delivering. This should not be confused with the directory in which local
710 mailboxes are stored, which is called a &"spool directory"& by some people. In
711 the Exim documentation, &"spool"& is always used in the first sense.
718 . ////////////////////////////////////////////////////////////////////////////
719 . ////////////////////////////////////////////////////////////////////////////
721 .chapter "Incorporated code" "CHID2"
722 .cindex "incorporated code"
723 .cindex "regular expressions" "library"
724 .cindex "PCRE"
725 A number of pieces of external code are included in the Exim distribution.
727 .ilist
728 Regular expressions are supported in the main Exim program and in the
729 Exim monitor using the freely-distributable PCRE library, copyright
730 &copy; University of Cambridge. The source to PCRE is no longer shipped with
731 Exim, so you will need to use the version of PCRE shipped with your system,
732 or obtain and install the full version of the library from
733 &url(ftp://ftp.csx.cam.ac.uk/pub/software/programming/pcre).
734 .next
735 .cindex "cdb" "acknowledgment"
736 Support for the cdb (Constant DataBase) lookup method is provided by code
737 contributed by Nigel Metheringham of (at the time he contributed it) Planet
738 Online Ltd. The implementation is completely contained within the code of Exim.
739 It does not link against an external cdb library. The code contains the
740 following statements:
742 .blockquote
743 Copyright &copy; 1998 Nigel Metheringham, Planet Online Ltd
745 This program is free software; you can redistribute it and/or modify it under
746 the terms of the GNU General Public License as published by the Free Software
747 Foundation; either version 2 of the License, or (at your option) any later
748 version.
749 This code implements Dan Bernstein's Constant DataBase (cdb) spec. Information,
750 the spec and sample code for cdb can be obtained from
751 &url(http://www.pobox.com/~djb/cdb.html). This implementation borrows
752 some code from Dan Bernstein's implementation (which has no license
753 restrictions applied to it).
754 .endblockquote
755 .next
756 .cindex "SPA authentication"
757 .cindex "Samba project"
758 .cindex "Microsoft Secure Password Authentication"
759 Client support for Microsoft's &'Secure Password Authentication'& is provided
760 by code contributed by Marc Prud'hommeaux. Server support was contributed by
761 Tom Kistner. This includes code taken from the Samba project, which is released
762 under the Gnu GPL.
763 .next
764 .cindex "Cyrus"
765 .cindex "&'pwcheck'& daemon"
766 .cindex "&'pwauthd'& daemon"
767 Support for calling the Cyrus &'pwcheck'& and &'saslauthd'& daemons is provided
768 by code taken from the Cyrus-SASL library and adapted by Alexander S.
769 Sabourenkov. The permission notice appears below, in accordance with the
770 conditions expressed therein.
772 .blockquote
773 Copyright &copy; 2001 Carnegie Mellon University. All rights reserved.
775 Redistribution and use in source and binary forms, with or without
776 modification, are permitted provided that the following conditions
777 are met:
779 .olist
780 Redistributions of source code must retain the above copyright
781 notice, this list of conditions and the following disclaimer.
782 .next
783 Redistributions in binary form must reproduce the above copyright
784 notice, this list of conditions and the following disclaimer in
785 the documentation and/or other materials provided with the
786 distribution.
787 .next
788 The name &"Carnegie Mellon University"& must not be used to
789 endorse or promote products derived from this software without
790 prior written permission. For permission or any other legal
791 details, please contact
792 .display
793 Office of Technology Transfer
794 Carnegie Mellon University
795 5000 Forbes Avenue
796 Pittsburgh, PA 15213-3890
797 (412) 268-4387, fax: (412) 268-7395
798 tech-transfer@andrew.cmu.edu
799 .endd
800 .next
801 Redistributions of any form whatsoever must retain the following
802 acknowledgment:
804 &"This product includes software developed by Computing Services
805 at Carnegie Mellon University (&url(http://www.cmu.edu/computing/)."&
814 .endlist
815 .endblockquote
817 .next
818 .cindex "Exim monitor" "acknowledgment"
819 .cindex "X-windows"
820 .cindex "Athena"
821 The Exim Monitor program, which is an X-Window application, includes
822 modified versions of the Athena StripChart and TextPop widgets.
823 This code is copyright by DEC and MIT, and their permission notice appears
824 below, in accordance with the conditions expressed therein.
826 .blockquote
827 Copyright 1987, 1988 by Digital Equipment Corporation, Maynard, Massachusetts,
828 and the Massachusetts Institute of Technology, Cambridge, Massachusetts.
830 All Rights Reserved
832 Permission to use, copy, modify, and distribute this software and its
833 documentation for any purpose and without fee is hereby granted,
834 provided that the above copyright notice appear in all copies and that
835 both that copyright notice and this permission notice appear in
836 supporting documentation, and that the names of Digital or MIT not be
837 used in advertising or publicity pertaining to distribution of the
838 software without specific, written prior permission.
847 .endblockquote
849 .next
850 Many people have contributed code fragments, some large, some small, that were
851 not covered by any specific licence requirements. It is assumed that the
852 contributors are happy to see their code incorporated into Exim under the GPL.
853 .endlist
859 . ////////////////////////////////////////////////////////////////////////////
860 . ////////////////////////////////////////////////////////////////////////////
862 .chapter "How Exim receives and delivers mail" "CHID11" &&&
863 "Receiving and delivering mail"
866 .section "Overall philosophy" "SECID10"
867 .cindex "design philosophy"
868 Exim is designed to work efficiently on systems that are permanently connected
869 to the Internet and are handling a general mix of mail. In such circumstances,
870 most messages can be delivered immediately. Consequently, Exim does not
871 maintain independent queues of messages for specific domains or hosts, though
872 it does try to send several messages in a single SMTP connection after a host
873 has been down, and it also maintains per-host retry information.
876 .section "Policy control" "SECID11"
877 .cindex "policy control" "overview"
878 Policy controls are now an important feature of MTAs that are connected to the
879 Internet. Perhaps their most important job is to stop MTAs being abused as
880 &"open relays"& by misguided individuals who send out vast amounts of
881 unsolicited junk, and want to disguise its source. Exim provides flexible
882 facilities for specifying policy controls on incoming mail:
884 .ilist
885 .cindex "&ACL;" "introduction"
886 Exim 4 (unlike previous versions of Exim) implements policy controls on
887 incoming mail by means of &'Access Control Lists'& (ACLs). Each list is a
888 series of statements that may either grant or deny access. ACLs can be used at
889 several places in the SMTP dialogue while receiving a message from a remote
890 host. However, the most common places are after each RCPT command, and at the
891 very end of the message. The sysadmin can specify conditions for accepting or
892 rejecting individual recipients or the entire message, respectively, at these
893 two points (see chapter &<<CHAPACL>>&). Denial of access results in an SMTP
894 error code.
895 .next
896 An ACL is also available for locally generated, non-SMTP messages. In this
897 case, the only available actions are to accept or deny the entire message.
898 .next
899 When Exim is compiled with the content-scanning extension, facilities are
900 provided in the ACL mechanism for passing the message to external virus and/or
901 spam scanning software. The result of such a scan is passed back to the ACL,
902 which can then use it to decide what to do with the message.
903 .next
904 When a message has been received, either from a remote host or from the local
905 host, but before the final acknowledgment has been sent, a locally supplied C
906 function called &[local_scan()]& can be run to inspect the message and decide
907 whether to accept it or not (see chapter &<<CHAPlocalscan>>&). If the message
908 is accepted, the list of recipients can be modified by the function.
909 .next
910 Using the &[local_scan()]& mechanism is another way of calling external scanner
911 software. The &%SA-Exim%& add-on package works this way. It does not require
912 Exim to be compiled with the content-scanning extension.
913 .next
914 After a message has been accepted, a further checking mechanism is available in
915 the form of the &'system filter'& (see chapter &<<CHAPsystemfilter>>&). This
916 runs at the start of every delivery process.
917 .endlist
921 .section "User filters" "SECID12"
922 .cindex "filter" "introduction"
923 .cindex "Sieve filter"
924 In a conventional Exim configuration, users are able to run private filters by
925 setting up appropriate &_.forward_& files in their home directories. See
926 chapter &<<CHAPredirect>>& (about the &(redirect)& router) for the
927 configuration needed to support this, and the separate document entitled
928 &'Exim's interfaces to mail filtering'& for user details. Two different kinds
929 of filtering are available:
931 .ilist
932 Sieve filters are written in the standard filtering language that is defined
933 by RFC 3028.
934 .next
935 Exim filters are written in a syntax that is unique to Exim, but which is more
936 powerful than Sieve, which it pre-dates.
937 .endlist
939 User filters are run as part of the routing process, described below.
943 .section "Message identification" "SECTmessiden"
944 .cindex "message ids" "details of format"
945 .cindex "format" "of message id"
946 .cindex "id of message"
947 .cindex "base62"
948 .cindex "base36"
949 .cindex "Darwin"
950 .cindex "Cygwin"
951 Every message handled by Exim is given a &'message id'& which is sixteen
952 characters long. It is divided into three parts, separated by hyphens, for
953 example &`16VDhn-0001bo-D3`&. Each part is a sequence of letters and digits,
954 normally encoding numbers in base 62. However, in the Darwin operating
955 system (Mac OS X) and when Exim is compiled to run under Cygwin, base 36
956 (avoiding the use of lower case letters) is used instead, because the message
957 id is used to construct file names, and the names of files in those systems are
958 not always case-sensitive.
960 .cindex "pid (process id)" "re-use of"
961 The detail of the contents of the message id have changed as Exim has evolved.
962 Earlier versions relied on the operating system not re-using a process id (pid)
963 within one second. On modern operating systems, this assumption can no longer
964 be made, so the algorithm had to be changed. To retain backward compatibility,
965 the format of the message id was retained, which is why the following rules are
966 somewhat eccentric:
968 .ilist
969 The first six characters of the message id are the time at which the message
970 started to be received, to a granularity of one second. That is, this field
971 contains the number of seconds since the start of the epoch (the normal Unix
972 way of representing the date and time of day).
973 .next
974 After the first hyphen, the next six characters are the id of the process that
975 received the message.
976 .next
977 There are two different possibilities for the final two characters:
978 .olist
979 .oindex "&%localhost_number%&"
980 If &%localhost_number%& is not set, this value is the fractional part of the
981 time of reception, normally in units of 1/2000 of a second, but for systems
982 that must use base 36 instead of base 62 (because of case-insensitive file
983 systems), the units are 1/1000 of a second.
984 .next
985 If &%localhost_number%& is set, it is multiplied by 200 (100) and added to
986 the fractional part of the time, which in this case is in units of 1/200
987 (1/100) of a second.
988 .endlist
989 .endlist
991 After a message has been received, Exim waits for the clock to tick at the
992 appropriate resolution before proceeding, so that if another message is
993 received by the same process, or by another process with the same (re-used)
994 pid, it is guaranteed that the time will be different. In most cases, the clock
995 will already have ticked while the message was being received.
998 .section "Receiving mail" "SECID13"
999 .cindex "receiving mail"
1000 .cindex "message" "reception"
1001 The only way Exim can receive mail from another host is using SMTP over
1002 TCP/IP, in which case the sender and recipient addresses are transferred using
1003 SMTP commands. However, from a locally running process (such as a user's MUA),
1004 there are several possibilities:
1006 .ilist
1007 If the process runs Exim with the &%-bm%& option, the message is read
1008 non-interactively (usually via a pipe), with the recipients taken from the
1009 command line, or from the body of the message if &%-t%& is also used.
1010 .next
1011 If the process runs Exim with the &%-bS%& option, the message is also read
1012 non-interactively, but in this case the recipients are listed at the start of
1013 the message in a series of SMTP RCPT commands, terminated by a DATA
1014 command. This is so-called &"batch SMTP"& format,
1015 but it isn't really SMTP. The SMTP commands are just another way of passing
1016 envelope addresses in a non-interactive submission.
1017 .next
1018 If the process runs Exim with the &%-bs%& option, the message is read
1019 interactively, using the SMTP protocol. A two-way pipe is normally used for
1020 passing data between the local process and the Exim process.
1021 This is &"real"& SMTP and is handled in the same way as SMTP over TCP/IP. For
1022 example, the ACLs for SMTP commands are used for this form of submission.
1023 .next
1024 A local process may also make a TCP/IP call to the host's loopback address
1025 ( or any other of its IP addresses. When receiving messages, Exim
1026 does not treat the loopback address specially. It treats all such connections
1027 in the same way as connections from other hosts.
1028 .endlist
1031 .cindex "message sender, constructed by Exim"
1032 .cindex "sender" "constructed by Exim"
1033 In the three cases that do not involve TCP/IP, the sender address is
1034 constructed from the login name of the user that called Exim and a default
1035 qualification domain (which can be set by the &%qualify_domain%& configuration
1036 option). For local or batch SMTP, a sender address that is passed using the
1037 SMTP MAIL command is ignored. However, the system administrator may allow
1038 certain users (&"trusted users"&) to specify a different sender address
1039 unconditionally, or all users to specify certain forms of different sender
1040 address. The &%-f%& option or the SMTP MAIL command is used to specify these
1041 different addresses. See section &<<SECTtrustedadmin>>& for details of trusted
1042 users, and the &%untrusted_set_sender%& option for a way of allowing untrusted
1043 users to change sender addresses.
1045 Messages received by either of the non-interactive mechanisms are subject to
1046 checking by the non-SMTP ACL, if one is defined. Messages received using SMTP
1047 (either over TCP/IP, or interacting with a local process) can be checked by a
1048 number of ACLs that operate at different times during the SMTP session. Either
1049 individual recipients, or the entire message, can be rejected if local policy
1050 requirements are not met. The &[local_scan()]& function (see chapter
1051 &<<CHAPlocalscan>>&) is run for all incoming messages.
1053 Exim can be configured not to start a delivery process when a message is
1054 received; this can be unconditional, or depend on the number of incoming SMTP
1055 connections or the system load. In these situations, new messages wait on the
1056 queue until a queue runner process picks them up. However, in standard
1057 configurations under normal conditions, delivery is started as soon as a
1058 message is received.
1064 .section "Handling an incoming message" "SECID14"
1065 .cindex "spool directory" "files that hold a message"
1066 .cindex "file" "how a message is held"
1067 When Exim accepts a message, it writes two files in its spool directory. The
1068 first contains the envelope information, the current status of the message, and
1069 the header lines, and the second contains the body of the message. The names of
1070 the two spool files consist of the message id, followed by &`-H`& for the
1071 file containing the envelope and header, and &`-D`& for the data file.
1073 .cindex "spool directory" "&_input_& sub-directory"
1074 By default all these message files are held in a single directory called
1075 &_input_& inside the general Exim spool directory. Some operating systems do
1076 not perform very well if the number of files in a directory gets large; to
1077 improve performance in such cases, the &%split_spool_directory%& option can be
1078 used. This causes Exim to split up the input files into 62 sub-directories
1079 whose names are single letters or digits. When this is done, the queue is
1080 processed one sub-directory at a time instead of all at once, which can improve
1081 overall performance even when there are not enough files in each directory to
1082 affect file system performance.
1084 The envelope information consists of the address of the message's sender and
1085 the addresses of the recipients. This information is entirely separate from
1086 any addresses contained in the header lines. The status of the message includes
1087 a list of recipients who have already received the message. The format of the
1088 first spool file is described in chapter &<<CHAPspool>>&.
1090 .cindex "rewriting" "addresses"
1091 Address rewriting that is specified in the rewrite section of the configuration
1092 (see chapter &<<CHAPrewrite>>&) is done once and for all on incoming addresses,
1093 both in the header lines and the envelope, at the time the message is accepted.
1094 If during the course of delivery additional addresses are generated (for
1095 example, via aliasing), these new addresses are rewritten as soon as they are
1096 generated. At the time a message is actually delivered (transported) further
1097 rewriting can take place; because this is a transport option, it can be
1098 different for different forms of delivery. It is also possible to specify the
1099 addition or removal of certain header lines at the time the message is
1100 delivered (see chapters &<<CHAProutergeneric>>& and
1101 &<<CHAPtransportgeneric>>&).
1105 .section "Life of a message" "SECID15"
1106 .cindex "message" "life of"
1107 .cindex "message" "frozen"
1108 A message remains in the spool directory until it is completely delivered to
1109 its recipients or to an error address, or until it is deleted by an
1110 administrator or by the user who originally created it. In cases when delivery
1111 cannot proceed &-- for example, when a message can neither be delivered to its
1112 recipients nor returned to its sender, the message is marked &"frozen"& on the
1113 spool, and no more deliveries are attempted.
1115 .cindex "frozen messages" "thawing"
1116 .cindex "message" "thawing frozen"
1117 An administrator can &"thaw"& such messages when the problem has been
1118 corrected, and can also freeze individual messages by hand if necessary. In
1119 addition, an administrator can force a delivery error, causing a bounce message
1120 to be sent.
1122 .oindex "&%timeout_frozen_after%&"
1123 .oindex "&%ignore_bounce_errors_after%&"
1124 There are options called &%ignore_bounce_errors_after%& and
1125 &%timeout_frozen_after%&, which discard frozen messages after a certain time.
1126 The first applies only to frozen bounces, the second to any frozen messages.
1128 .cindex "message" "log file for"
1129 .cindex "log" "file for each message"
1130 While Exim is working on a message, it writes information about each delivery
1131 attempt to its main log file. This includes successful, unsuccessful, and
1132 delayed deliveries for each recipient (see chapter &<<CHAPlog>>&). The log
1133 lines are also written to a separate &'message log'& file for each message.
1134 These logs are solely for the benefit of the administrator, and are normally
1135 deleted along with the spool files when processing of a message is complete.
1136 The use of individual message logs can be disabled by setting
1137 &%no_message_logs%&; this might give an improvement in performance on very busy
1138 systems.
1140 .cindex "journal file"
1141 .cindex "file" "journal"
1142 All the information Exim itself needs to set up a delivery is kept in the first
1143 spool file, along with the header lines. When a successful delivery occurs, the
1144 address is immediately written at the end of a journal file, whose name is the
1145 message id followed by &`-J`&. At the end of a delivery run, if there are some
1146 addresses left to be tried again later, the first spool file (the &`-H`& file)
1147 is updated to indicate which these are, and the journal file is then deleted.
1148 Updating the spool file is done by writing a new file and renaming it, to
1149 minimize the possibility of data loss.
1151 Should the system or the program crash after a successful delivery but before
1152 the spool file has been updated, the journal is left lying around. The next
1153 time Exim attempts to deliver the message, it reads the journal file and
1154 updates the spool file before proceeding. This minimizes the chances of double
1155 deliveries caused by crashes.
1159 .section "Processing an address for delivery" "SECTprocaddress"
1160 .cindex "drivers" "definition of"
1161 .cindex "router" "definition of"
1162 .cindex "transport" "definition of"
1163 The main delivery processing elements of Exim are called &'routers'& and
1164 &'transports'&, and collectively these are known as &'drivers'&. Code for a
1165 number of them is provided in the source distribution, and compile-time options
1166 specify which ones are included in the binary. Run time options specify which
1167 ones are actually used for delivering messages.
1169 .cindex "drivers" "instance definition"
1170 Each driver that is specified in the run time configuration is an &'instance'&
1171 of that particular driver type. Multiple instances are allowed; for example,
1172 you can set up several different &(smtp)& transports, each with different
1173 option values that might specify different ports or different timeouts. Each
1174 instance has its own identifying name. In what follows we will normally use the
1175 instance name when discussing one particular instance (that is, one specific
1176 configuration of the driver), and the generic driver name when discussing
1177 the driver's features in general.
1179 A &'router'& is a driver that operates on an address, either determining how
1180 its delivery should happen, by assigning it to a specific transport, or
1181 converting the address into one or more new addresses (for example, via an
1182 alias file). A router may also explicitly choose to fail an address, causing it
1183 to be bounced.
1185 A &'transport'& is a driver that transmits a copy of the message from Exim's
1186 spool to some destination. There are two kinds of transport: for a &'local'&
1187 transport, the destination is a file or a pipe on the local host, whereas for a
1188 &'remote'& transport the destination is some other host. A message is passed
1189 to a specific transport as a result of successful routing. If a message has
1190 several recipients, it may be passed to a number of different transports.
1192 .cindex "preconditions" "definition of"
1193 An address is processed by passing it to each configured router instance in
1194 turn, subject to certain preconditions, until a router accepts the address or
1195 specifies that it should be bounced. We will describe this process in more
1196 detail shortly. First, as a simple example, we consider how each recipient
1197 address in a message is processed in a small configuration of three routers.
1199 To make this a more concrete example, it is described in terms of some actual
1200 routers, but remember, this is only an example. You can configure Exim's
1201 routers in many different ways, and there may be any number of routers in a
1202 configuration.
1204 The first router that is specified in a configuration is often one that handles
1205 addresses in domains that are not recognized specially by the local host. These
1206 are typically addresses for arbitrary domains on the Internet. A precondition
1207 is set up which looks for the special domains known to the host (for example,
1208 its own domain name), and the router is run for addresses that do &'not'&
1209 match. Typically, this is a router that looks up domains in the DNS in order to
1210 find the hosts to which this address routes. If it succeeds, the address is
1211 assigned to a suitable SMTP transport; if it does not succeed, the router is
1212 configured to fail the address.
1214 The second router is reached only when the domain is recognized as one that
1215 &"belongs"& to the local host. This router does redirection &-- also known as
1216 aliasing and forwarding. When it generates one or more new addresses from the
1217 original, each of them is routed independently from the start. Otherwise, the
1218 router may cause an address to fail, or it may simply decline to handle the
1219 address, in which case the address is passed to the next router.
1221 The final router in many configurations is one that checks to see if the
1222 address belongs to a local mailbox. The precondition may involve a check to
1223 see if the local part is the name of a login account, or it may look up the
1224 local part in a file or a database. If its preconditions are not met, or if
1225 the router declines, we have reached the end of the routers. When this happens,
1226 the address is bounced.
1230 .section "Processing an address for verification" "SECID16"
1231 .cindex "router" "for verification"
1232 .cindex "verifying address" "overview"
1233 As well as being used to decide how to deliver to an address, Exim's routers
1234 are also used for &'address verification'&. Verification can be requested as
1235 one of the checks to be performed in an ACL for incoming messages, on both
1236 sender and recipient addresses, and it can be tested using the &%-bv%& and
1237 &%-bvs%& command line options.
1239 When an address is being verified, the routers are run in &"verify mode"&. This
1240 does not affect the way the routers work, but it is a state that can be
1241 detected. By this means, a router can be skipped or made to behave differently
1242 when verifying. A common example is a configuration in which the first router
1243 sends all messages to a message-scanning program, unless they have been
1244 previously scanned. Thus, the first router accepts all addresses without any
1245 checking, making it useless for verifying. Normally, the &%no_verify%& option
1246 would be set for such a router, causing it to be skipped in verify mode.
1251 .section "Running an individual router" "SECTrunindrou"
1252 .cindex "router" "running details"
1253 .cindex "preconditions" "checking"
1254 .cindex "router" "result of running"
1255 As explained in the example above, a number of preconditions are checked before
1256 running a router. If any are not met, the router is skipped, and the address is
1257 passed to the next router. When all the preconditions on a router &'are'& met,
1258 the router is run. What happens next depends on the outcome, which is one of
1259 the following:
1261 .ilist
1262 &'accept'&: The router accepts the address, and either assigns it to a
1263 transport, or generates one or more &"child"& addresses. Processing the
1264 original address ceases,
1265 .oindex "&%unseen%&"
1266 unless the &%unseen%& option is set on the router. This option
1267 can be used to set up multiple deliveries with different routing (for example,
1268 for keeping archive copies of messages). When &%unseen%& is set, the address is
1269 passed to the next router. Normally, however, an &'accept'& return marks the
1270 end of routing.
1272 Any child addresses generated by the router are processed independently,
1273 starting with the first router by default. It is possible to change this by
1274 setting the &%redirect_router%& option to specify which router to start at for
1275 child addresses. Unlike &%pass_router%& (see below) the router specified by
1276 &%redirect_router%& may be anywhere in the router configuration.
1277 .next
1278 &'pass'&: The router recognizes the address, but cannot handle it itself. It
1279 requests that the address be passed to another router. By default the address
1280 is passed to the next router, but this can be changed by setting the
1281 &%pass_router%& option. However, (unlike &%redirect_router%&) the named router
1282 must be below the current router (to avoid loops).
1283 .next
1284 &'decline'&: The router declines to accept the address because it does not
1285 recognize it at all. By default, the address is passed to the next router, but
1286 this can be prevented by setting the &%no_more%& option. When &%no_more%& is
1287 set, all the remaining routers are skipped. In effect, &%no_more%& converts
1288 &'decline'& into &'fail'&.
1289 .next
1290 &'fail'&: The router determines that the address should fail, and queues it for
1291 the generation of a bounce message. There is no further processing of the
1292 original address unless &%unseen%& is set on the router.
1293 .next
1294 &'defer'&: The router cannot handle the address at the present time. (A
1295 database may be offline, or a DNS lookup may have timed out.) No further
1296 processing of the address happens in this delivery attempt. It is tried again
1297 next time the message is considered for delivery.
1298 .next
1299 &'error'&: There is some error in the router (for example, a syntax error in
1300 its configuration). The action is as for defer.
1301 .endlist
1303 If an address reaches the end of the routers without having been accepted by
1304 any of them, it is bounced as unrouteable. The default error message in this
1305 situation is &"unrouteable address"&, but you can set your own message by
1306 making use of the &%cannot_route_message%& option. This can be set for any
1307 router; the value from the last router that &"saw"& the address is used.
1309 Sometimes while routing you want to fail a delivery when some conditions are
1310 met but others are not, instead of passing the address on for further routing.
1311 You can do this by having a second router that explicitly fails the delivery
1312 when the relevant conditions are met. The &(redirect)& router has a &"fail"&
1313 facility for this purpose.
1316 .section "Duplicate addresses" "SECID17"
1317 .cindex "case of local parts"
1318 .cindex "address duplicate, discarding"
1319 .cindex "duplicate addresses"
1320 Once routing is complete, Exim scans the addresses that are assigned to local
1321 and remote transports, and discards any duplicates that it finds. During this
1322 check, local parts are treated as case-sensitive. This happens only when
1323 actually delivering a message; when testing routers with &%-bt%&, all the
1324 routed addresses are shown.
1328 .section "Router preconditions" "SECTrouprecon"
1329 .cindex "router" "preconditions, order of processing"
1330 .cindex "preconditions" "order of processing"
1331 The preconditions that are tested for each router are listed below, in the
1332 order in which they are tested. The individual configuration options are
1333 described in more detail in chapter &<<CHAProutergeneric>>&.
1335 .ilist
1336 The &%local_part_prefix%& and &%local_part_suffix%& options can specify that
1337 the local parts handled by the router may or must have certain prefixes and/or
1338 suffixes. If a mandatory affix (prefix or suffix) is not present, the router is
1339 skipped. These conditions are tested first. When an affix is present, it is
1340 removed from the local part before further processing, including the evaluation
1341 of any other conditions.
1342 .next
1343 Routers can be designated for use only when not verifying an address, that is,
1344 only when routing it for delivery (or testing its delivery routing). If the
1345 &%verify%& option is set false, the router is skipped when Exim is verifying an
1346 address.
1347 Setting the &%verify%& option actually sets two options, &%verify_sender%& and
1348 &%verify_recipient%&, which independently control the use of the router for
1349 sender and recipient verification. You can set these options directly if
1350 you want a router to be used for only one type of verification.
1351 .next
1352 If the &%address_test%& option is set false, the router is skipped when Exim is
1353 run with the &%-bt%& option to test an address routing. This can be helpful
1354 when the first router sends all new messages to a scanner of some sort; it
1355 makes it possible to use &%-bt%& to test subsequent delivery routing without
1356 having to simulate the effect of the scanner.
1357 .next
1358 Routers can be designated for use only when verifying an address, as
1359 opposed to routing it for delivery. The &%verify_only%& option controls this.
1360 .next
1361 Individual routers can be explicitly skipped when running the routers to
1362 check an address given in the SMTP EXPN command (see the &%expn%& option).
1363 .next
1364 If the &%domains%& option is set, the domain of the address must be in the set
1365 of domains that it defines.
1366 .next
1367 .vindex "&$local_part_prefix$&"
1368 .vindex "&$local_part$&"
1369 .vindex "&$local_part_suffix$&"
1370 If the &%local_parts%& option is set, the local part of the address must be in
1371 the set of local parts that it defines. If &%local_part_prefix%& or
1372 &%local_part_suffix%& is in use, the prefix or suffix is removed from the local
1373 part before this check. If you want to do precondition tests on local parts
1374 that include affixes, you can do so by using a &%condition%& option (see below)
1375 that uses the variables &$local_part$&, &$local_part_prefix$&, and
1376 &$local_part_suffix$& as necessary.
1377 .next
1378 .vindex "&$local_user_uid$&"
1379 .vindex "&$local_user_gid$&"
1380 .vindex "&$home$&"
1381 If the &%check_local_user%& option is set, the local part must be the name of
1382 an account on the local host. If this check succeeds, the uid and gid of the
1383 local user are placed in &$local_user_uid$& and &$local_user_gid$& and the
1384 user's home directory is placed in &$home$&; these values can be used in the
1385 remaining preconditions.
1386 .next
1387 If the &%router_home_directory%& option is set, it is expanded at this point,
1388 because it overrides the value of &$home$&. If this expansion were left till
1389 later, the value of &$home$& as set by &%check_local_user%& would be used in
1390 subsequent tests. Having two different values of &$home$& in the same router
1391 could lead to confusion.
1392 .next
1393 If the &%senders%& option is set, the envelope sender address must be in the
1394 set of addresses that it defines.
1395 .next
1396 If the &%require_files%& option is set, the existence or non-existence of
1397 specified files is tested.
1398 .next
1399 .cindex "customizing" "precondition"
1400 If the &%condition%& option is set, it is evaluated and tested. This option
1401 uses an expanded string to allow you to set up your own custom preconditions.
1402 Expanded strings are described in chapter &<<CHAPexpand>>&.
1403 .endlist
1406 Note that &%require_files%& comes near the end of the list, so you cannot use
1407 it to check for the existence of a file in which to lookup up a domain, local
1408 part, or sender. However, as these options are all expanded, you can use the
1409 &%exists%& expansion condition to make such tests within each condition. The
1410 &%require_files%& option is intended for checking files that the router may be
1411 going to use internally, or which are needed by a specific transport (for
1412 example, &_.procmailrc_&).
1416 .section "Delivery in detail" "SECID18"
1417 .cindex "delivery" "in detail"
1418 When a message is to be delivered, the sequence of events is as follows:
1420 .ilist
1421 If a system-wide filter file is specified, the message is passed to it. The
1422 filter may add recipients to the message, replace the recipients, discard the
1423 message, cause a new message to be generated, or cause the message delivery to
1424 fail. The format of the system filter file is the same as for Exim user filter
1425 files, described in the separate document entitled &'Exim's interfaces to mail
1426 filtering'&.
1427 .cindex "Sieve filter" "not available for system filter"
1428 (&*Note*&: Sieve cannot be used for system filter files.)
1430 Some additional features are available in system filters &-- see chapter
1431 &<<CHAPsystemfilter>>& for details. Note that a message is passed to the system
1432 filter only once per delivery attempt, however many recipients it has. However,
1433 if there are several delivery attempts because one or more addresses could not
1434 be immediately delivered, the system filter is run each time. The filter
1435 condition &%first_delivery%& can be used to detect the first run of the system
1436 filter.
1437 .next
1438 Each recipient address is offered to each configured router in turn, subject to
1439 its preconditions, until one is able to handle it. If no router can handle the
1440 address, that is, if they all decline, the address is failed. Because routers
1441 can be targeted at particular domains, several locally handled domains can be
1442 processed entirely independently of each other.
1443 .next
1444 .cindex "routing" "loops in"
1445 .cindex "loop" "while routing"
1446 A router that accepts an address may assign it to a local or a remote
1447 transport. However, the transport is not run at this time. Instead, the address
1448 is placed on a list for the particular transport, which will be run later.
1449 Alternatively, the router may generate one or more new addresses (typically
1450 from alias, forward, or filter files). New addresses are fed back into this
1451 process from the top, but in order to avoid loops, a router ignores any address
1452 which has an identically-named ancestor that was processed by itself.
1453 .next
1454 When all the routing has been done, addresses that have been successfully
1455 handled are passed to their assigned transports. When local transports are
1456 doing real local deliveries, they handle only one address at a time, but if a
1457 local transport is being used as a pseudo-remote transport (for example, to
1458 collect batched SMTP messages for transmission by some other means) multiple
1459 addresses can be handled. Remote transports can always handle more than one
1460 address at a time, but can be configured not to do so, or to restrict multiple
1461 addresses to the same domain.
1462 .next
1463 Each local delivery to a file or a pipe runs in a separate process under a
1464 non-privileged uid, and these deliveries are run one at a time. Remote
1465 deliveries also run in separate processes, normally under a uid that is private
1466 to Exim (&"the Exim user"&), but in this case, several remote deliveries can be
1467 run in parallel. The maximum number of simultaneous remote deliveries for any
1468 one message is set by the &%remote_max_parallel%& option.
1469 The order in which deliveries are done is not defined, except that all local
1470 deliveries happen before any remote deliveries.
1471 .next
1472 .cindex "queue runner"
1473 When it encounters a local delivery during a queue run, Exim checks its retry
1474 database to see if there has been a previous temporary delivery failure for the
1475 address before running the local transport. If there was a previous failure,
1476 Exim does not attempt a new delivery until the retry time for the address is
1477 reached. However, this happens only for delivery attempts that are part of a
1478 queue run. Local deliveries are always attempted when delivery immediately
1479 follows message reception, even if retry times are set for them. This makes for
1480 better behaviour if one particular message is causing problems (for example,
1481 causing quota overflow, or provoking an error in a filter file).
1482 .next
1483 .cindex "delivery" "retry in remote transports"
1484 Remote transports do their own retry handling, since an address may be
1485 deliverable to one of a number of hosts, each of which may have a different
1486 retry time. If there have been previous temporary failures and no host has
1487 reached its retry time, no delivery is attempted, whether in a queue run or
1488 not. See chapter &<<CHAPretry>>& for details of retry strategies.
1489 .next
1490 If there were any permanent errors, a bounce message is returned to an
1491 appropriate address (the sender in the common case), with details of the error
1492 for each failing address. Exim can be configured to send copies of bounce
1493 messages to other addresses.
1494 .next
1495 .cindex "delivery" "deferral"
1496 If one or more addresses suffered a temporary failure, the message is left on
1497 the queue, to be tried again later. Delivery of these addresses is said to be
1498 &'deferred'&.
1499 .next
1500 When all the recipient addresses have either been delivered or bounced,
1501 handling of the message is complete. The spool files and message log are
1502 deleted, though the message log can optionally be preserved if required.
1503 .endlist
1508 .section "Retry mechanism" "SECID19"
1509 .cindex "delivery" "retry mechanism"
1510 .cindex "retry" "description of mechanism"
1511 .cindex "queue runner"
1512 Exim's mechanism for retrying messages that fail to get delivered at the first
1513 attempt is the queue runner process. You must either run an Exim daemon that
1514 uses the &%-q%& option with a time interval to start queue runners at regular
1515 intervals, or use some other means (such as &'cron'&) to start them. If you do
1516 not arrange for queue runners to be run, messages that fail temporarily at the
1517 first attempt will remain on your queue for ever. A queue runner process works
1518 its way through the queue, one message at a time, trying each delivery that has
1519 passed its retry time.
1520 You can run several queue runners at once.
1522 Exim uses a set of configured rules to determine when next to retry the failing
1523 address (see chapter &<<CHAPretry>>&). These rules also specify when Exim
1524 should give up trying to deliver to the address, at which point it generates a
1525 bounce message. If no retry rules are set for a particular host, address, and
1526 error combination, no retries are attempted, and temporary errors are treated
1527 as permanent.
1531 .section "Temporary delivery failure" "SECID20"
1532 .cindex "delivery" "temporary failure"
1533 There are many reasons why a message may not be immediately deliverable to a
1534 particular address. Failure to connect to a remote machine (because it, or the
1535 connection to it, is down) is one of the most common. Temporary failures may be
1536 detected during routing as well as during the transport stage of delivery.
1537 Local deliveries may be delayed if NFS files are unavailable, or if a mailbox
1538 is on a file system where the user is over quota. Exim can be configured to
1539 impose its own quotas on local mailboxes; where system quotas are set they will
1540 also apply.
1542 If a host is unreachable for a period of time, a number of messages may be
1543 waiting for it by the time it recovers, and sending them in a single SMTP
1544 connection is clearly beneficial. Whenever a delivery to a remote host is
1545 deferred,
1546 .cindex "hints database"
1547 Exim makes a note in its hints database, and whenever a successful
1548 SMTP delivery has happened, it looks to see if any other messages are waiting
1549 for the same host. If any are found, they are sent over the same SMTP
1550 connection, subject to a configuration limit as to the maximum number in any
1551 one connection.
1555 .section "Permanent delivery failure" "SECID21"
1556 .cindex "delivery" "permanent failure"
1557 .cindex "bounce message" "when generated"
1558 When a message cannot be delivered to some or all of its intended recipients, a
1559 bounce message is generated. Temporary delivery failures turn into permanent
1560 errors when their timeout expires. All the addresses that fail in a given
1561 delivery attempt are listed in a single message. If the original message has
1562 many recipients, it is possible for some addresses to fail in one delivery
1563 attempt and others to fail subsequently, giving rise to more than one bounce
1564 message. The wording of bounce messages can be customized by the administrator.
1565 See chapter &<<CHAPemsgcust>>& for details.
1567 .cindex "&'X-Failed-Recipients:'& header line"
1568 Bounce messages contain an &'X-Failed-Recipients:'& header line that lists the
1569 failed addresses, for the benefit of programs that try to analyse such messages
1570 automatically.
1572 .cindex "bounce message" "recipient of"
1573 A bounce message is normally sent to the sender of the original message, as
1574 obtained from the message's envelope. For incoming SMTP messages, this is the
1575 address given in the MAIL command. However, when an address is expanded via a
1576 forward or alias file, an alternative address can be specified for delivery
1577 failures of the generated addresses. For a mailing list expansion (see section
1578 &<<SECTmailinglists>>&) it is common to direct bounce messages to the manager
1579 of the list.
1583 .section "Failures to deliver bounce messages" "SECID22"
1584 .cindex "bounce message" "failure to deliver"
1585 If a bounce message (either locally generated or received from a remote host)
1586 itself suffers a permanent delivery failure, the message is left on the queue,
1587 but it is frozen, awaiting the attention of an administrator. There are options
1588 that can be used to make Exim discard such failed messages, or to keep them
1589 for only a short time (see &%timeout_frozen_after%& and
1590 &%ignore_bounce_errors_after%&).
1596 . ////////////////////////////////////////////////////////////////////////////
1597 . ////////////////////////////////////////////////////////////////////////////
1599 .chapter "Building and installing Exim" "CHID3"
1600 .scindex IIDbuex "building Exim"
1602 .section "Unpacking" "SECID23"
1603 Exim is distributed as a gzipped or bzipped tar file which, when unpacked,
1604 creates a directory with the name of the current release (for example,
1605 &_exim-&version;_&) into which the following files are placed:
1607 .table2 140pt
1608 .irow &_ACKNOWLEDGMENTS_& "contains some acknowledgments"
1609 .irow &_CHANGES_& "contains a reference to where changes are &&&
1610 documented"
1611 .irow &_LICENCE_& "the GNU General Public Licence"
1612 .irow &_Makefile_& "top-level make file"
1613 .irow &_NOTICE_& "conditions for the use of Exim"
1614 .irow &_README_& "list of files, directories and simple build &&&
1615 instructions"
1616 .endtable
1618 Other files whose names begin with &_README_& may also be present. The
1619 following subdirectories are created:
1621 .table2 140pt
1622 .irow &_Local_& "an empty directory for local configuration files"
1623 .irow &_OS_& "OS-specific files"
1624 .irow &_doc_& "documentation files"
1625 .irow &_exim_monitor_& "source files for the Exim monitor"
1626 .irow &_scripts_& "scripts used in the build process"
1627 .irow &_src_& "remaining source files"
1628 .irow &_util_& "independent utilities"
1629 .endtable
1631 The main utility programs are contained in the &_src_& directory, and are built
1632 with the Exim binary. The &_util_& directory contains a few optional scripts
1633 that may be useful to some sites.
1636 .section "Multiple machine architectures and operating systems" "SECID24"
1637 .cindex "building Exim" "multiple OS/architectures"
1638 The building process for Exim is arranged to make it easy to build binaries for
1639 a number of different architectures and operating systems from the same set of
1640 source files. Compilation does not take place in the &_src_& directory.
1641 Instead, a &'build directory'& is created for each architecture and operating
1642 system.
1643 .cindex "symbolic link" "to build directory"
1644 Symbolic links to the sources are installed in this directory, which is where
1645 the actual building takes place. In most cases, Exim can discover the machine
1646 architecture and operating system for itself, but the defaults can be
1647 overridden if necessary.
1650 .section "PCRE library" "SECTpcre"
1651 .cindex "PCRE library"
1652 Exim no longer has an embedded PCRE library as the vast majority of
1653 modern systems include PCRE as a system library, although you may need
1654 to install the PCRE or PCRE development package for your operating
1655 system. If your system has a normal PCRE installation the Exim build
1656 process will need no further configuration. If the library or the
1657 headers are in an unusual location you will need to set the PCRE_LIBS
1658 and INCLUDE directives appropriately. If your operating system has no
1659 PCRE support then you will need to obtain and build the current PCRE
1660 from &url(ftp://ftp.csx.cam.ac.uk/pub/software/programming/pcre/).
1662 .section "DBM libraries" "SECTdb"
1663 .cindex "DBM libraries" "discussion of"
1664 .cindex "hints database" "DBM files used for"
1665 Even if you do not use any DBM files in your configuration, Exim still needs a
1666 DBM library in order to operate, because it uses indexed files for its hints
1667 databases. Unfortunately, there are a number of DBM libraries in existence, and
1668 different operating systems often have different ones installed.
1670 .cindex "Solaris" "DBM library for"
1671 .cindex "IRIX, DBM library for"
1672 .cindex "BSD, DBM library for"
1673 .cindex "Linux, DBM library for"
1674 If you are using Solaris, IRIX, one of the modern BSD systems, or a modern
1675 Linux distribution, the DBM configuration should happen automatically, and you
1676 may be able to ignore this section. Otherwise, you may have to learn more than
1677 you would like about DBM libraries from what follows.
1679 .cindex "&'ndbm'& DBM library"
1680 Licensed versions of Unix normally contain a library of DBM functions operating
1681 via the &'ndbm'& interface, and this is what Exim expects by default. Free
1682 versions of Unix seem to vary in what they contain as standard. In particular,
1683 some early versions of Linux have no default DBM library, and different
1684 distributors have chosen to bundle different libraries with their packaged
1685 versions. However, the more recent releases seem to have standardized on the
1686 Berkeley DB library.
1688 Different DBM libraries have different conventions for naming the files they
1689 use. When a program opens a file called &_dbmfile_&, there are several
1690 possibilities:
1692 .olist
1693 A traditional &'ndbm'& implementation, such as that supplied as part of
1694 Solaris, operates on two files called &_dbmfile.dir_& and &_dbmfile.pag_&.
1695 .next
1696 .cindex "&'gdbm'& DBM library"
1697 The GNU library, &'gdbm'&, operates on a single file. If used via its &'ndbm'&
1698 compatibility interface it makes two different hard links to it with names
1699 &_dbmfile.dir_& and &_dbmfile.pag_&, but if used via its native interface, the
1700 file name is used unmodified.
1701 .next
1702 .cindex "Berkeley DB library"
1703 The Berkeley DB package, if called via its &'ndbm'& compatibility interface,
1704 operates on a single file called &_dbmfile.db_&, but otherwise looks to the
1705 programmer exactly the same as the traditional &'ndbm'& implementation.
1706 .next
1707 If the Berkeley package is used in its native mode, it operates on a single
1708 file called &_dbmfile_&; the programmer's interface is somewhat different to
1709 the traditional &'ndbm'& interface.
1710 .next
1711 To complicate things further, there are several very different versions of the
1712 Berkeley DB package. Version 1.85 was stable for a very long time, releases
1713 2.&'x'& and 3.&'x'& were current for a while, but the latest versions are now
1714 numbered 4.&'x'&. Maintenance of some of the earlier releases has ceased. All
1715 versions of Berkeley DB can be obtained from
1716 &url(http://www.sleepycat.com/).
1717 .next
1718 .cindex "&'tdb'& DBM library"
1719 Yet another DBM library, called &'tdb'&, is available from
1720 &url(http://download.sourceforge.net/tdb). It has its own interface, and also
1721 operates on a single file.
1722 .endlist
1724 .cindex "USE_DB"
1725 .cindex "DBM libraries" "configuration for building"
1726 Exim and its utilities can be compiled to use any of these interfaces. In order
1727 to use any version of the Berkeley DB package in native mode, you must set
1728 USE_DB in an appropriate configuration file (typically
1729 &_Local/Makefile_&). For example:
1730 .code
1731 USE_DB=yes
1732 .endd
1733 Similarly, for gdbm you set USE_GDBM, and for tdb you set USE_TDB. An
1734 error is diagnosed if you set more than one of these.
1736 At the lowest level, the build-time configuration sets none of these options,
1737 thereby assuming an interface of type (1). However, some operating system
1738 configuration files (for example, those for the BSD operating systems and
1739 Linux) assume type (4) by setting USE_DB as their default, and the
1740 configuration files for Cygwin set USE_GDBM. Anything you set in
1741 &_Local/Makefile_&, however, overrides these system defaults.
1743 As well as setting USE_DB, USE_GDBM, or USE_TDB, it may also be
1744 necessary to set DBMLIB, to cause inclusion of the appropriate library, as
1745 in one of these lines:
1746 .code
1747 DBMLIB = -ldb
1748 DBMLIB = -ltdb
1749 .endd
1750 Settings like that will work if the DBM library is installed in the standard
1751 place. Sometimes it is not, and the library's header file may also not be in
1752 the default path. You may need to set INCLUDE to specify where the header
1753 file is, and to specify the path to the library more fully in DBMLIB, as in
1754 this example:
1755 .code
1756 INCLUDE=-I/usr/local/include/db-4.1
1757 DBMLIB=/usr/local/lib/db-4.1/libdb.a
1758 .endd
1759 There is further detailed discussion about the various DBM libraries in the
1760 file &_doc/dbm.discuss.txt_& in the Exim distribution.
1764 .section "Pre-building configuration" "SECID25"
1765 .cindex "building Exim" "pre-building configuration"
1766 .cindex "configuration for building Exim"
1767 .cindex "&_Local/Makefile_&"
1768 .cindex "&_src/EDITME_&"
1769 Before building Exim, a local configuration file that specifies options
1770 independent of any operating system has to be created with the name
1771 &_Local/Makefile_&. A template for this file is supplied as the file
1772 &_src/EDITME_&, and it contains full descriptions of all the option settings
1773 therein. These descriptions are therefore not repeated here. If you are
1774 building Exim for the first time, the simplest thing to do is to copy
1775 &_src/EDITME_& to &_Local/Makefile_&, then read it and edit it appropriately.
1777 There are three settings that you must supply, because Exim will not build
1778 without them. They are the location of the run time configuration file
1779 (CONFIGURE_FILE), the directory in which Exim binaries will be installed
1780 (BIN_DIRECTORY), and the identity of the Exim user (EXIM_USER and
1781 maybe EXIM_GROUP as well). The value of CONFIGURE_FILE can in fact be
1782 a colon-separated list of file names; Exim uses the first of them that exists.
1784 There are a few other parameters that can be specified either at build time or
1785 at run time, to enable the same binary to be used on a number of different
1786 machines. However, if the locations of Exim's spool directory and log file
1787 directory (if not within the spool directory) are fixed, it is recommended that
1788 you specify them in &_Local/Makefile_& instead of at run time, so that errors
1789 detected early in Exim's execution (such as a malformed configuration file) can
1790 be logged.
1792 .cindex "content scanning" "specifying at build time"
1793 Exim's interfaces for calling virus and spam scanning software directly from
1794 access control lists are not compiled by default. If you want to include these
1795 facilities, you need to set
1796 .code
1798 .endd
1799 in your &_Local/Makefile_&. For details of the facilities themselves, see
1800 chapter &<<CHAPexiscan>>&.
1803 .cindex "&_Local/eximon.conf_&"
1804 .cindex "&_exim_monitor/EDITME_&"
1805 If you are going to build the Exim monitor, a similar configuration process is
1806 required. The file &_exim_monitor/EDITME_& must be edited appropriately for
1807 your installation and saved under the name &_Local/eximon.conf_&. If you are
1808 happy with the default settings described in &_exim_monitor/EDITME_&,
1809 &_Local/eximon.conf_& can be empty, but it must exist.
1811 This is all the configuration that is needed in straightforward cases for known
1812 operating systems. However, the building process is set up so that it is easy
1813 to override options that are set by default or by operating-system-specific
1814 configuration files, for example to change the name of the C compiler, which
1815 defaults to &%gcc%&. See section &<<SECToverride>>& below for details of how to
1816 do this.
1820 .section "Support for iconv()" "SECID26"
1821 .cindex "&[iconv()]& support"
1822 .cindex "RFC 2047"
1823 The contents of header lines in messages may be encoded according to the rules
1824 described RFC 2047. This makes it possible to transmit characters that are not
1825 in the ASCII character set, and to label them as being in a particular
1826 character set. When Exim is inspecting header lines by means of the &%$h_%&
1827 mechanism, it decodes them, and translates them into a specified character set
1828 (default ISO-8859-1). The translation is possible only if the operating system
1829 supports the &[iconv()]& function.
1831 However, some of the operating systems that supply &[iconv()]& do not support
1832 very many conversions. The GNU &%libiconv%& library (available from
1833 &url(http://www.gnu.org/software/libiconv/)) can be installed on such
1834 systems to remedy this deficiency, as well as on systems that do not supply
1835 &[iconv()]& at all. After installing &%libiconv%&, you should add
1836 .code
1837 HAVE_ICONV=yes
1838 .endd
1839 to your &_Local/Makefile_& and rebuild Exim.
1843 .section "Including TLS/SSL encryption support" "SECTinctlsssl"
1844 .cindex "TLS" "including support for TLS"
1845 .cindex "encryption" "including support for"
1846 .cindex "SUPPORT_TLS"
1847 .cindex "OpenSSL" "building Exim with"
1848 .cindex "GnuTLS" "building Exim with"
1849 Exim can be built to support encrypted SMTP connections, using the STARTTLS
1850 command as per RFC 2487. It can also support legacy clients that expect to
1851 start a TLS session immediately on connection to a non-standard port (see the
1852 &%tls_on_connect_ports%& runtime option and the &%-tls-on-connect%& command
1853 line option).
1855 If you want to build Exim with TLS support, you must first install either the
1856 OpenSSL or GnuTLS library. There is no cryptographic code in Exim itself for
1857 implementing SSL.
1859 If OpenSSL is installed, you should set
1860 .code
1861 SUPPORT_TLS=yes
1862 TLS_LIBS=-lssl -lcrypto
1863 .endd
1864 in &_Local/Makefile_&. You may also need to specify the locations of the
1865 OpenSSL library and include files. For example:
1866 .code
1867 SUPPORT_TLS=yes
1868 TLS_LIBS=-L/usr/local/openssl/lib -lssl -lcrypto
1869 TLS_INCLUDE=-I/usr/local/openssl/include/
1870 .endd
1871 .cindex "USE_GNUTLS"
1872 If GnuTLS is installed, you should set
1873 .code
1874 SUPPORT_TLS=yes
1875 USE_GNUTLS=yes
1876 TLS_LIBS=-lgnutls -ltasn1 -lgcrypt
1877 .endd
1878 in &_Local/Makefile_&, and again you may need to specify the locations of the
1879 library and include files. For example:
1880 .code
1881 SUPPORT_TLS=yes
1882 USE_GNUTLS=yes
1883 TLS_LIBS=-L/usr/gnu/lib -lgnutls -ltasn1 -lgcrypt
1884 TLS_INCLUDE=-I/usr/gnu/include
1885 .endd
1886 You do not need to set TLS_INCLUDE if the relevant directory is already
1887 specified in INCLUDE. Details of how to configure Exim to make use of TLS are
1888 given in chapter &<<CHAPTLS>>&.
1893 .section "Use of tcpwrappers" "SECID27"
1895 .cindex "tcpwrappers, building Exim to support"
1896 .cindex "USE_TCP_WRAPPERS"
1898 .cindex "tcp_wrappers_daemon_name"
1899 Exim can be linked with the &'tcpwrappers'& library in order to check incoming
1900 SMTP calls using the &'tcpwrappers'& control files. This may be a convenient
1901 alternative to Exim's own checking facilities for installations that are
1902 already making use of &'tcpwrappers'& for other purposes. To do this, you
1903 should set USE_TCP_WRAPPERS in &_Local/Makefile_&, arrange for the file
1904 &_tcpd.h_& to be available at compile time, and also ensure that the library
1905 &_libwrap.a_& is available at link time, typically by including &%-lwrap%& in
1906 EXTRALIBS_EXIM. For example, if &'tcpwrappers'& is installed in &_/usr/local_&,
1907 you might have
1908 .code
1910 CFLAGS=-O -I/usr/local/include
1911 EXTRALIBS_EXIM=-L/usr/local/lib -lwrap
1912 .endd
1913 in &_Local/Makefile_&. The daemon name to use in the &'tcpwrappers'& control
1914 files is &"exim"&. For example, the line
1915 .code
1916 exim : LOCAL 192.168.1. .friendly.domain.example
1917 .endd
1918 in your &_/etc/hosts.allow_& file allows connections from the local host, from
1919 the subnet, and from all hosts in &'friendly.domain.example'&.
1920 All other connections are denied. The daemon name used by &'tcpwrappers'&
1921 can be changed at build time by setting TCP_WRAPPERS_DAEMON_NAME in
1922 in &_Local/Makefile_&, or by setting tcp_wrappers_daemon_name in the
1923 configure file. Consult the &'tcpwrappers'& documentation for
1924 further details.
1927 .section "Including support for IPv6" "SECID28"
1928 .cindex "IPv6" "including support for"
1929 Exim contains code for use on systems that have IPv6 support. Setting
1930 &`HAVE_IPV6=YES`& in &_Local/Makefile_& causes the IPv6 code to be included;
1931 it may also be necessary to set IPV6_INCLUDE and IPV6_LIBS on systems
1932 where the IPv6 support is not fully integrated into the normal include and
1933 library files.
1935 Two different types of DNS record for handling IPv6 addresses have been
1936 defined. AAAA records (analogous to A records for IPv4) are in use, and are
1937 currently seen as the mainstream. Another record type called A6 was proposed
1938 as better than AAAA because it had more flexibility. However, it was felt to be
1939 over-complex, and its status was reduced to &"experimental"&. It is not known
1940 if anyone is actually using A6 records. Exim has support for A6 records, but
1941 this is included only if you set &`SUPPORT_A6=YES`& in &_Local/Makefile_&. The
1942 support has not been tested for some time.
1946 .section "Dynamically loaded lookup module support" "SECTdynamicmodules"
1947 .cindex "lookup modules"
1948 .cindex "dynamic modules"
1949 .cindex ".so building"
1950 On some platforms, Exim supports not compiling all lookup types directly into
1951 the main binary, instead putting some into external modules which can be loaded
1952 on demand.
1953 This permits packagers to build Exim with support for lookups with extensive
1954 library dependencies without requiring all users to install all of those
1955 dependencies.
1956 Most, but not all, lookup types can be built this way.
1958 Set &`LOOKUP_MODULE_DIR`& to the directory into which the modules will be
1959 installed; Exim will only load modules from that directory, as a security
1960 measure. You will need to set &`CFLAGS_DYNAMIC`& if not already defined
1961 for your OS; see &_OS/Makefile-Linux_& for an example.
1962 Some other requirements for adjusting &`EXTRALIBS`& may also be necessary,
1963 see &_src/EDITME_& for details.
1965 Then, for each module to be loaded dynamically, define the relevant
1966 &`LOOKUP_`&<&'lookup_type'&> flags to have the value "2" instead of "yes".
1967 For example, this will build in lsearch but load sqlite and mysql support
1968 on demand:
1969 .code
1973 .endd
1976 .section "The building process" "SECID29"
1977 .cindex "build directory"
1978 Once &_Local/Makefile_& (and &_Local/eximon.conf_&, if required) have been
1979 created, run &'make'& at the top level. It determines the architecture and
1980 operating system types, and creates a build directory if one does not exist.
1981 For example, on a Sun system running Solaris 8, the directory
1982 &_build-SunOS5-5.8-sparc_& is created.
1983 .cindex "symbolic link" "to source files"
1984 Symbolic links to relevant source files are installed in the build directory.
1986 &*Warning*&: The &%-j%& (parallel) flag must not be used with &'make'&; the
1987 building process fails if it is set.
1989 If this is the first time &'make'& has been run, it calls a script that builds
1990 a make file inside the build directory, using the configuration files from the
1991 &_Local_& directory. The new make file is then passed to another instance of
1992 &'make'&. This does the real work, building a number of utility scripts, and
1993 then compiling and linking the binaries for the Exim monitor (if configured), a
1994 number of utility programs, and finally Exim itself. The command &`make
1995 makefile`& can be used to force a rebuild of the make file in the build
1996 directory, should this ever be necessary.
1998 If you have problems building Exim, check for any comments there may be in the
1999 &_README_& file concerning your operating system, and also take a look at the
2000 FAQ, where some common problems are covered.
2004 .section 'Output from &"make"&' "SECID283"
2005 The output produced by the &'make'& process for compile lines is often very
2006 unreadable, because these lines can be very long. For this reason, the normal
2007 output is suppressed by default, and instead output similar to that which
2008 appears when compiling the 2.6 Linux kernel is generated: just a short line for
2009 each module that is being compiled or linked. However, it is still possible to
2010 get the full output, by calling &'make'& like this:
2011 .code
2012 FULLECHO='' make -e
2013 .endd
2014 The value of FULLECHO defaults to &"@"&, the flag character that suppresses
2015 command reflection in &'make'&. When you ask for the full output, it is
2016 given in addition to the short output.
2020 .section "Overriding build-time options for Exim" "SECToverride"
2021 .cindex "build-time options, overriding"
2022 The main make file that is created at the beginning of the building process
2023 consists of the concatenation of a number of files which set configuration
2024 values, followed by a fixed set of &'make'& instructions. If a value is set
2025 more than once, the last setting overrides any previous ones. This provides a
2026 convenient way of overriding defaults. The files that are concatenated are, in
2027 order:
2028 .display
2029 &_OS/Makefile-Default_&
2030 &_OS/Makefile-_&<&'ostype'&>
2031 &_Local/Makefile_&
2032 &_Local/Makefile-_&<&'ostype'&>
2033 &_Local/Makefile-_&<&'archtype'&>
2034 &_Local/Makefile-_&<&'ostype'&>-<&'archtype'&>
2035 &_OS/Makefile-Base_&
2036 .endd
2037 .cindex "&_Local/Makefile_&"
2038 .cindex "building Exim" "operating system type"
2039 .cindex "building Exim" "architecture type"
2040 where <&'ostype'&> is the operating system type and <&'archtype'&> is the
2041 architecture type. &_Local/Makefile_& is required to exist, and the building
2042 process fails if it is absent. The other three &_Local_& files are optional,
2043 and are often not needed.
2045 The values used for <&'ostype'&> and <&'archtype'&> are obtained from scripts
2046 called &_scripts/os-type_& and &_scripts/arch-type_& respectively. If either of
2047 the environment variables EXIM_OSTYPE or EXIM_ARCHTYPE is set, their
2048 values are used, thereby providing a means of forcing particular settings.
2049 Otherwise, the scripts try to get values from the &%uname%& command. If this
2050 fails, the shell variables OSTYPE and ARCHTYPE are inspected. A number
2051 of &'ad hoc'& transformations are then applied, to produce the standard names
2052 that Exim expects. You can run these scripts directly from the shell in order
2053 to find out what values are being used on your system.
2056 &_OS/Makefile-Default_& contains comments about the variables that are set
2057 therein. Some (but not all) are mentioned below. If there is something that
2058 needs changing, review the contents of this file and the contents of the make
2059 file for your operating system (&_OS/Makefile-<ostype>_&) to see what the
2060 default values are.
2063 .cindex "building Exim" "overriding default settings"
2064 If you need to change any of the values that are set in &_OS/Makefile-Default_&
2065 or in &_OS/Makefile-<ostype>_&, or to add any new definitions, you do not
2066 need to change the original files. Instead, you should make the changes by
2067 putting the new values in an appropriate &_Local_& file. For example,
2068 .cindex "Tru64-Unix build-time settings"
2069 when building Exim in many releases of the Tru64-Unix (formerly Digital UNIX,
2070 formerly DEC-OSF1) operating system, it is necessary to specify that the C
2071 compiler is called &'cc'& rather than &'gcc'&. Also, the compiler must be
2072 called with the option &%-std1%&, to make it recognize some of the features of
2073 Standard C that Exim uses. (Most other compilers recognize Standard C by
2074 default.) To do this, you should create a file called &_Local/Makefile-OSF1_&
2075 containing the lines
2076 .code
2077 CC=cc
2078 CFLAGS=-std1
2079 .endd
2080 If you are compiling for just one operating system, it may be easier to put
2081 these lines directly into &_Local/Makefile_&.
2083 Keeping all your local configuration settings separate from the distributed
2084 files makes it easy to transfer them to new versions of Exim simply by copying
2085 the contents of the &_Local_& directory.
2088 .cindex "NIS lookup type" "including support for"
2089 .cindex "NIS+ lookup type" "including support for"
2090 .cindex "LDAP" "including support for"
2091 .cindex "lookup" "inclusion in binary"
2092 Exim contains support for doing LDAP, NIS, NIS+, and other kinds of file
2093 lookup, but not all systems have these components installed, so the default is
2094 not to include the relevant code in the binary. All the different kinds of file
2095 and database lookup that Exim supports are implemented as separate code modules
2096 which are included only if the relevant compile-time options are set. In the
2097 case of LDAP, NIS, and NIS+, the settings for &_Local/Makefile_& are:
2098 .code
2099 LOOKUP_LDAP=yes
2100 LOOKUP_NIS=yes
2102 .endd
2103 and similar settings apply to the other lookup types. They are all listed in
2104 &_src/EDITME_&. In many cases the relevant include files and interface
2105 libraries need to be installed before compiling Exim.
2106 .cindex "cdb" "including support for"
2107 However, there are some optional lookup types (such as cdb) for which
2108 the code is entirely contained within Exim, and no external include
2109 files or libraries are required. When a lookup type is not included in the
2110 binary, attempts to configure Exim to use it cause run time configuration
2111 errors.
2113 .cindex "Perl" "including support for"
2114 Exim can be linked with an embedded Perl interpreter, allowing Perl
2115 subroutines to be called during string expansion. To enable this facility,
2116 .code
2117 EXIM_PERL=perl.o
2118 .endd
2119 must be defined in &_Local/Makefile_&. Details of this facility are given in
2120 chapter &<<CHAPperl>>&.
2122 .cindex "X11 libraries, location of"
2123 The location of the X11 libraries is something that varies a lot between
2124 operating systems, and there may be different versions of X11 to cope
2125 with. Exim itself makes no use of X11, but if you are compiling the Exim
2126 monitor, the X11 libraries must be available.
2127 The following three variables are set in &_OS/Makefile-Default_&:
2128 .code
2129 X11=/usr/X11R6
2130 XINCLUDE=-I$(X11)/include
2131 XLFLAGS=-L$(X11)/lib
2132 .endd
2133 These are overridden in some of the operating-system configuration files. For
2134 example, in &_OS/Makefile-SunOS5_& there is
2135 .code
2136 X11=/usr/openwin
2137 XINCLUDE=-I$(X11)/include
2138 XLFLAGS=-L$(X11)/lib -R$(X11)/lib
2139 .endd
2140 If you need to override the default setting for your operating system, place a
2141 definition of all three of these variables into your
2142 &_Local/Makefile-<ostype>_& file.
2144 .cindex "EXTRALIBS"
2145 If you need to add any extra libraries to the link steps, these can be put in a
2146 variable called EXTRALIBS, which appears in all the link commands, but by
2147 default is not defined. In contrast, EXTRALIBS_EXIM is used only on the
2148 command for linking the main Exim binary, and not for any associated utilities.
2150 .cindex "DBM libraries" "configuration for building"
2151 There is also DBMLIB, which appears in the link commands for binaries that
2152 use DBM functions (see also section &<<SECTdb>>&). Finally, there is
2153 EXTRALIBS_EXIMON, which appears only in the link step for the Exim monitor
2154 binary, and which can be used, for example, to include additional X11
2155 libraries.
2157 .cindex "configuration file" "editing"
2158 The make file copes with rebuilding Exim correctly if any of the configuration
2159 files are edited. However, if an optional configuration file is deleted, it is
2160 necessary to touch the associated non-optional file (that is,
2161 &_Local/Makefile_& or &_Local/eximon.conf_&) before rebuilding.
2164 .section "OS-specific header files" "SECID30"
2165 .cindex "&_os.h_&"
2166 .cindex "building Exim" "OS-specific C header files"
2167 The &_OS_& directory contains a number of files with names of the form
2168 &_os.h-<ostype>_&. These are system-specific C header files that should not
2169 normally need to be changed. There is a list of macro settings that are
2170 recognized in the file &_OS/os.configuring_&, which should be consulted if you
2171 are porting Exim to a new operating system.
2175 .section "Overriding build-time options for the monitor" "SECID31"
2176 .cindex "building Eximon"
2177 A similar process is used for overriding things when building the Exim monitor,
2178 where the files that are involved are
2179 .display
2180 &_OS/eximon.conf-Default_&
2181 &_OS/eximon.conf-_&<&'ostype'&>
2182 &_Local/eximon.conf_&
2183 &_Local/eximon.conf-_&<&'ostype'&>
2184 &_Local/eximon.conf-_&<&'archtype'&>
2185 &_Local/eximon.conf-_&<&'ostype'&>-<&'archtype'&>
2186 .endd
2187 .cindex "&_Local/eximon.conf_&"
2188 As with Exim itself, the final three files need not exist, and in this case the
2189 &_OS/eximon.conf-<ostype>_& file is also optional. The default values in
2190 &_OS/eximon.conf-Default_& can be overridden dynamically by setting environment
2191 variables of the same name, preceded by EXIMON_. For example, setting
2192 EXIMON_LOG_DEPTH in the environment overrides the value of
2193 LOG_DEPTH at run time.
2194 .ecindex IIDbuex
2197 .section "Installing Exim binaries and scripts" "SECID32"
2198 .cindex "installing Exim"
2199 .cindex "BIN_DIRECTORY"
2200 The command &`make install`& runs the &(exim_install)& script with no
2201 arguments. The script copies binaries and utility scripts into the directory
2202 whose name is specified by the BIN_DIRECTORY setting in &_Local/Makefile_&.
2203 .cindex "setuid" "installing Exim with"
2204 The install script copies files only if they are newer than the files they are
2205 going to replace. The Exim binary is required to be owned by root and have the
2206 &'setuid'& bit set, for normal configurations. Therefore, you must run &`make
2207 install`& as root so that it can set up the Exim binary in this way. However, in
2208 some special situations (for example, if a host is doing no local deliveries)
2209 it may be possible to run Exim without making the binary setuid root (see
2210 chapter &<<CHAPsecurity>>& for details).
2212 .cindex "CONFIGURE_FILE"
2213 Exim's run time configuration file is named by the CONFIGURE_FILE setting
2214 in &_Local/Makefile_&. If this names a single file, and the file does not
2215 exist, the default configuration file &_src/configure.default_& is copied there
2216 by the installation script. If a run time configuration file already exists, it
2217 is left alone. If CONFIGURE_FILE is a colon-separated list, naming several
2218 alternative files, no default is installed.
2220 .cindex "system aliases file"
2221 .cindex "&_/etc/aliases_&"
2222 One change is made to the default configuration file when it is installed: the
2223 default configuration contains a router that references a system aliases file.
2224 The path to this file is set to the value specified by
2225 SYSTEM_ALIASES_FILE in &_Local/Makefile_& (&_/etc/aliases_& by default).
2226 If the system aliases file does not exist, the installation script creates it,
2227 and outputs a comment to the user.
2229 The created file contains no aliases, but it does contain comments about the
2230 aliases a site should normally have. Mail aliases have traditionally been
2231 kept in &_/etc/aliases_&. However, some operating systems are now using
2232 &_/etc/mail/aliases_&. You should check if yours is one of these, and change
2233 Exim's configuration if necessary.
2235 The default configuration uses the local host's name as the only local domain,
2236 and is set up to do local deliveries into the shared directory &_/var/mail_&,
2237 running as the local user. System aliases and &_.forward_& files in users' home
2238 directories are supported, but no NIS or NIS+ support is configured. Domains
2239 other than the name of the local host are routed using the DNS, with delivery
2240 over SMTP.
2242 It is possible to install Exim for special purposes (such as building a binary
2243 distribution) in a private part of the file system. You can do this by a
2244 command such as
2245 .code
2246 make DESTDIR=/some/directory/ install
2247 .endd
2248 This has the effect of pre-pending the specified directory to all the file
2249 paths, except the name of the system aliases file that appears in the default
2250 configuration. (If a default alias file is created, its name &'is'& modified.)
2251 For backwards compatibility, ROOT is used if DESTDIR is not set,
2252 but this usage is deprecated.
2254 .cindex "installing Exim" "what is not installed"
2255 Running &'make install'& does not copy the Exim 4 conversion script
2256 &'convert4r4'&. You will probably run this only once if you are
2257 upgrading from Exim 3. None of the documentation files in the &_doc_&
2258 directory are copied, except for the info files when you have set
2259 INFO_DIRECTORY, as described in section &<<SECTinsinfdoc>>& below.
2261 For the utility programs, old versions are renamed by adding the suffix &_.O_&
2262 to their names. The Exim binary itself, however, is handled differently. It is
2263 installed under a name that includes the version number and the compile number,
2264 for example &_exim-&version;-1_&. The script then arranges for a symbolic link
2265 called &_exim_& to point to the binary. If you are updating a previous version
2266 of Exim, the script takes care to ensure that the name &_exim_& is never absent
2267 from the directory (as seen by other processes).
2269 .cindex "installing Exim" "testing the script"
2270 If you want to see what the &'make install'& will do before running it for
2271 real, you can pass the &%-n%& option to the installation script by this
2272 command:
2273 .code
2274 make INSTALL_ARG=-n install
2275 .endd
2276 The contents of the variable INSTALL_ARG are passed to the installation
2277 script. You do not need to be root to run this test. Alternatively, you can run
2278 the installation script directly, but this must be from within the build
2279 directory. For example, from the top-level Exim directory you could use this
2280 command:
2281 .code
2282 (cd build-SunOS5-5.5.1-sparc; ../scripts/exim_install -n)
2283 .endd
2284 .cindex "installing Exim" "install script options"
2285 There are two other options that can be supplied to the installation script.
2287 .ilist
2288 &%-no_chown%& bypasses the call to change the owner of the installed binary
2289 to root, and the call to make it a setuid binary.
2290 .next
2291 &%-no_symlink%& bypasses the setting up of the symbolic link &_exim_& to the
2292 installed binary.
2293 .endlist
2295 INSTALL_ARG can be used to pass these options to the script. For example:
2296 .code
2297 make INSTALL_ARG=-no_symlink install
2298 .endd
2299 The installation script can also be given arguments specifying which files are
2300 to be copied. For example, to install just the Exim binary, and nothing else,
2301 without creating the symbolic link, you could use:
2302 .code
2303 make INSTALL_ARG='-no_symlink exim' install
2304 .endd
2308 .section "Installing info documentation" "SECTinsinfdoc"
2309 .cindex "installing Exim" "&'info'& documentation"
2310 Not all systems use the GNU &'info'& system for documentation, and for this
2311 reason, the Texinfo source of Exim's documentation is not included in the main
2312 distribution. Instead it is available separately from the ftp site (see section
2313 &<<SECTavail>>&).
2315 If you have defined INFO_DIRECTORY in &_Local/Makefile_& and the Texinfo
2316 source of the documentation is found in the source tree, running &`make
2317 install`& automatically builds the info files and installs them.
2321 .section "Setting up the spool directory" "SECID33"
2322 .cindex "spool directory" "creating"
2323 When it starts up, Exim tries to create its spool directory if it does not
2324 exist. The Exim uid and gid are used for the owner and group of the spool
2325 directory. Sub-directories are automatically created in the spool directory as
2326 necessary.
2331 .section "Testing" "SECID34"
2332 .cindex "testing" "installation"
2333 Having installed Exim, you can check that the run time configuration file is
2334 syntactically valid by running the following command, which assumes that the
2335 Exim binary directory is within your PATH environment variable:
2336 .code
2337 exim -bV
2338 .endd
2339 If there are any errors in the configuration file, Exim outputs error messages.
2340 Otherwise it outputs the version number and build date,
2341 the DBM library that is being used, and information about which drivers and
2342 other optional code modules are included in the binary.
2343 Some simple routing tests can be done by using the address testing option. For
2344 example,
2345 .display
2346 &`exim -bt`& <&'local username'&>
2347 .endd
2348 should verify that it recognizes a local mailbox, and
2349 .display
2350 &`exim -bt`& <&'remote address'&>
2351 .endd
2352 a remote one. Then try getting it to deliver mail, both locally and remotely.
2353 This can be done by passing messages directly to Exim, without going through a
2354 user agent. For example:
2355 .code
2356 exim -v postmaster@your.domain.example
2357 From: user@your.domain.example
2358 To: postmaster@your.domain.example
2359 Subject: Testing Exim
2361 This is a test message.
2362 ^D
2363 .endd
2364 The &%-v%& option causes Exim to output some verification of what it is doing.
2365 In this case you should see copies of three log lines, one for the message's
2366 arrival, one for its delivery, and one containing &"Completed"&.
2368 .cindex "delivery" "problems with"
2369 If you encounter problems, look at Exim's log files (&'mainlog'& and
2370 &'paniclog'&) to see if there is any relevant information there. Another source
2371 of information is running Exim with debugging turned on, by specifying the
2372 &%-d%& option. If a message is stuck on Exim's spool, you can force a delivery
2373 with debugging turned on by a command of the form
2374 .display
2375 &`exim -d -M`& <&'exim-message-id'&>
2376 .endd
2377 You must be root or an &"admin user"& in order to do this. The &%-d%& option
2378 produces rather a lot of output, but you can cut this down to specific areas.
2379 For example, if you use &%-d-all+route%& only the debugging information
2380 relevant to routing is included. (See the &%-d%& option in chapter
2381 &<<CHAPcommandline>>& for more details.)
2383 .cindex '&"sticky"& bit'
2384 .cindex "lock files"
2385 One specific problem that has shown up on some sites is the inability to do
2386 local deliveries into a shared mailbox directory, because it does not have the
2387 &"sticky bit"& set on it. By default, Exim tries to create a lock file before
2388 writing to a mailbox file, and if it cannot create the lock file, the delivery
2389 is deferred. You can get round this either by setting the &"sticky bit"& on the
2390 directory, or by setting a specific group for local deliveries and allowing
2391 that group to create files in the directory (see the comments above the
2392 &(local_delivery)& transport in the default configuration file). Another
2393 approach is to configure Exim not to use lock files, but just to rely on
2394 &[fcntl()]& locking instead. However, you should do this only if all user
2395 agents also use &[fcntl()]& locking. For further discussion of locking issues,
2396 see chapter &<<CHAPappendfile>>&.
2398 One thing that cannot be tested on a system that is already running an MTA is
2399 the receipt of incoming SMTP mail on the standard SMTP port. However, the
2400 &%-oX%& option can be used to run an Exim daemon that listens on some other
2401 port, or &'inetd'& can be used to do this. The &%-bh%& option and the
2402 &'exim_checkaccess'& utility can be used to check out policy controls on
2403 incoming SMTP mail.
2405 Testing a new version on a system that is already running Exim can most easily
2406 be done by building a binary with a different CONFIGURE_FILE setting. From
2407 within the run time configuration, all other file and directory names
2408 that Exim uses can be altered, in order to keep it entirely clear of the
2409 production version.
2412 .section "Replacing another MTA with Exim" "SECID35"
2413 .cindex "replacing another MTA"
2414 Building and installing Exim for the first time does not of itself put it in
2415 general use. The name by which the system's MTA is called by mail user agents
2416 is either &_/usr/sbin/sendmail_&, or &_/usr/lib/sendmail_& (depending on the
2417 operating system), and it is necessary to make this name point to the &'exim'&
2418 binary in order to get the user agents to pass messages to Exim. This is
2419 normally done by renaming any existing file and making &_/usr/sbin/sendmail_&
2420 or &_/usr/lib/sendmail_&
2421 .cindex "symbolic link" "to &'exim'& binary"
2422 a symbolic link to the &'exim'& binary. It is a good idea to remove any setuid
2423 privilege and executable status from the old MTA. It is then necessary to stop
2424 and restart the mailer daemon, if one is running.
2426 .cindex "FreeBSD, MTA indirection"
2427 .cindex "&_/etc/mail/mailer.conf_&"
2428 Some operating systems have introduced alternative ways of switching MTAs. For
2429 example, if you are running FreeBSD, you need to edit the file
2430 &_/etc/mail/mailer.conf_& instead of setting up a symbolic link as just
2431 described. A typical example of the contents of this file for running Exim is
2432 as follows:
2433 .code
2434 sendmail /usr/exim/bin/exim
2435 send-mail /usr/exim/bin/exim
2436 mailq /usr/exim/bin/exim -bp
2437 newaliases /usr/bin/true
2438 .endd
2439 Once you have set up the symbolic link, or edited &_/etc/mail/mailer.conf_&,
2440 your Exim installation is &"live"&. Check it by sending a message from your
2441 favourite user agent.
2443 You should consider what to tell your users about the change of MTA. Exim may
2444 have different capabilities to what was previously running, and there are
2445 various operational differences such as the text of messages produced by
2446 command line options and in bounce messages. If you allow your users to make
2447 use of Exim's filtering capabilities, you should make the document entitled
2448 &'Exim's interface to mail filtering'& available to them.
2452 .section "Upgrading Exim" "SECID36"
2453 .cindex "upgrading Exim"
2454 If you are already running Exim on your host, building and installing a new
2455 version automatically makes it available to MUAs, or any other programs that
2456 call the MTA directly. However, if you are running an Exim daemon, you do need
2457 to send it a HUP signal, to make it re-execute itself, and thereby pick up the
2458 new binary. You do not need to stop processing mail in order to install a new
2459 version of Exim. The install script does not modify an existing runtime
2460 configuration file.
2465 .section "Stopping the Exim daemon on Solaris" "SECID37"
2466 .cindex "Solaris" "stopping Exim on"
2467 The standard command for stopping the mailer daemon on Solaris is
2468 .code
2469 /etc/init.d/sendmail stop
2470 .endd
2471 If &_/usr/lib/sendmail_& has been turned into a symbolic link, this script
2472 fails to stop Exim because it uses the command &'ps -e'& and greps the output
2473 for the text &"sendmail"&; this is not present because the actual program name
2474 (that is, &"exim"&) is given by the &'ps'& command with these options. A
2475 solution is to replace the line that finds the process id with something like
2476 .code
2477 pid=`cat /var/spool/exim/exim-daemon.pid`
2478 .endd
2479 to obtain the daemon's pid directly from the file that Exim saves it in.
2481 Note, however, that stopping the daemon does not &"stop Exim"&. Messages can
2482 still be received from local processes, and if automatic delivery is configured
2483 (the normal case), deliveries will still occur.
2488 . ////////////////////////////////////////////////////////////////////////////
2489 . ////////////////////////////////////////////////////////////////////////////
2491 .chapter "The Exim command line" "CHAPcommandline"
2492 .scindex IIDclo1 "command line" "options"
2493 .scindex IIDclo2 "options" "command line"
2494 Exim's command line takes the standard Unix form of a sequence of options,
2495 each starting with a hyphen character, followed by a number of arguments. The
2496 options are compatible with the main options of Sendmail, and there are also
2497 some additional options, some of which are compatible with Smail 3. Certain
2498 combinations of options do not make sense, and provoke an error if used.
2499 The form of the arguments depends on which options are set.
2502 .section "Setting options by program name" "SECID38"
2503 .cindex "&'mailq'&"
2504 If Exim is called under the name &'mailq'&, it behaves as if the option &%-bp%&
2505 were present before any other options.
2506 The &%-bp%& option requests a listing of the contents of the mail queue on the
2507 standard output.
2508 This feature is for compatibility with some systems that contain a command of
2509 that name in one of the standard libraries, symbolically linked to
2510 &_/usr/sbin/sendmail_& or &_/usr/lib/sendmail_&.
2512 .cindex "&'rsmtp'&"
2513 If Exim is called under the name &'rsmtp'& it behaves as if the option &%-bS%&
2514 were present before any other options, for compatibility with Smail. The
2515 &%-bS%& option is used for reading in a number of messages in batched SMTP
2516 format.
2518 .cindex "&'rmail'&"
2519 If Exim is called under the name &'rmail'& it behaves as if the &%-i%& and
2520 &%-oee%& options were present before any other options, for compatibility with
2521 Smail. The name &'rmail'& is used as an interface by some UUCP systems.
2523 .cindex "&'runq'&"
2524 .cindex "queue runner"
2525 If Exim is called under the name &'runq'& it behaves as if the option &%-q%&
2526 were present before any other options, for compatibility with Smail. The &%-q%&
2527 option causes a single queue runner process to be started.
2529 .cindex "&'newaliases'&"
2530 .cindex "alias file" "building"
2531 .cindex "Sendmail compatibility" "calling Exim as &'newaliases'&"
2532 If Exim is called under the name &'newaliases'& it behaves as if the option
2533 &%-bi%& were present before any other options, for compatibility with Sendmail.
2534 This option is used for rebuilding Sendmail's alias file. Exim does not have
2535 the concept of a single alias file, but can be configured to run a given
2536 command if called with the &%-bi%& option.
2539 .section "Trusted and admin users" "SECTtrustedadmin"
2540 Some Exim options are available only to &'trusted users'& and others are
2541 available only to &'admin users'&. In the description below, the phrases &"Exim
2542 user"& and &"Exim group"& mean the user and group defined by EXIM_USER and
2543 EXIM_GROUP in &_Local/Makefile_& or set by the &%exim_user%& and
2544 &%exim_group%& options. These do not necessarily have to use the name &"exim"&.
2546 .ilist
2547 .cindex "trusted users" "definition of"
2548 .cindex "user" "trusted definition of"
2549 The trusted users are root, the Exim user, any user listed in the
2550 &%trusted_users%& configuration option, and any user whose current group or any
2551 supplementary group is one of those listed in the &%trusted_groups%&
2552 configuration option. Note that the Exim group is not automatically trusted.
2554 .cindex '&"From"& line'
2555 .cindex "envelope sender"
2556 Trusted users are always permitted to use the &%-f%& option or a leading
2557 &"From&~"& line to specify the envelope sender of a message that is passed to
2558 Exim through the local interface (see the &%-bm%& and &%-f%& options below).
2559 See the &%untrusted_set_sender%& option for a way of permitting non-trusted
2560 users to set envelope senders.
2562 .cindex "&'From:'& header line"
2563 .cindex "&'Sender:'& header line"
2564 For a trusted user, there is never any check on the contents of the &'From:'&
2565 header line, and a &'Sender:'& line is never added. Furthermore, any existing
2566 &'Sender:'& line in incoming local (non-TCP/IP) messages is not removed.
2568 Trusted users may also specify a host name, host address, interface address,
2569 protocol name, ident value, and authentication data when submitting a message
2570 locally. Thus, they are able to insert messages into Exim's queue locally that
2571 have the characteristics of messages received from a remote host. Untrusted
2572 users may in some circumstances use &%-f%&, but can never set the other values
2573 that are available to trusted users.
2574 .next
2575 .cindex "user" "admin definition of"
2576 .cindex "admin user" "definition of"
2577 The admin users are root, the Exim user, and any user that is a member of the
2578 Exim group or of any group listed in the &%admin_groups%& configuration option.
2579 The current group does not have to be one of these groups.
2581 Admin users are permitted to list the queue, and to carry out certain
2582 operations on messages, for example, to force delivery failures. It is also
2583 necessary to be an admin user in order to see the full information provided by
2584 the Exim monitor, and full debugging output.
2586 By default, the use of the &%-M%&, &%-q%&, &%-R%&, and &%-S%& options to cause
2587 Exim to attempt delivery of messages on its queue is restricted to admin users.
2588 However, this restriction can be relaxed by setting the &%prod_requires_admin%&
2589 option false (that is, specifying &%no_prod_requires_admin%&).
2591 Similarly, the use of the &%-bp%& option to list all the messages in the queue
2592 is restricted to admin users unless &%queue_list_requires_admin%& is set
2593 false.
2594 .endlist
2597 &*Warning*&: If you configure your system so that admin users are able to
2598 edit Exim's configuration file, you are giving those users an easy way of
2599 getting root. There is further discussion of this issue at the start of chapter
2600 &<<CHAPconf>>&.
2605 .section "Command line options" "SECID39"
2606 Exim's command line options are described in alphabetical order below. If none
2607 of the options that specifies a specific action (such as starting the daemon or
2608 a queue runner, or testing an address, or receiving a message in a specific
2609 format, or listing the queue) are present, and there is at least one argument
2610 on the command line, &%-bm%& (accept a local message on the standard input,
2611 with the arguments specifying the recipients) is assumed. Otherwise, Exim
2612 outputs a brief message about itself and exits.
2614 . ////////////////////////////////////////////////////////////////////////////
2615 . Insert a stylized XML comment here, to identify the start of the command line
2616 . options. This is for the benefit of the Perl script that automatically
2617 . creates a man page for the options.
2618 . ////////////////////////////////////////////////////////////////////////////
2620 .literal xml
2621 <!-- === Start of command line options === -->
2622 .literal off
2625 .vlist
2626 .vitem &%--%&
2627 .oindex "--"
2628 .cindex "options" "command line; terminating"
2629 This is a pseudo-option whose only purpose is to terminate the options and
2630 therefore to cause subsequent command line items to be treated as arguments
2631 rather than options, even if they begin with hyphens.
2633 .vitem &%--help%&
2634 .oindex "&%--help%&"
2635 This option causes Exim to output a few sentences stating what it is.
2636 The same output is generated if the Exim binary is called with no options and
2637 no arguments.
2639 .vitem &%--version%&
2640 .oindex "&%--version%&"
2641 This option is an alias for &%-bV%& and causes version information to be
2642 displayed.
2644 .vitem &%-B%&<&'type'&>
2645 .oindex "&%-B%&"
2646 .cindex "8-bit characters"
2647 .cindex "Sendmail compatibility" "8-bit characters"
2648 This is a Sendmail option for selecting 7 or 8 bit processing. Exim is 8-bit
2649 clean; it ignores this option.
2651 .vitem &%-bd%&
2652 .oindex "&%-bd%&"
2653 .cindex "daemon"
2654 .cindex "SMTP" "listener"
2655 .cindex "queue runner"
2656 This option runs Exim as a daemon, awaiting incoming SMTP connections. Usually
2657 the &%-bd%& option is combined with the &%-q%&<&'time'&> option, to specify
2658 that the daemon should also initiate periodic queue runs.
2660 The &%-bd%& option can be used only by an admin user. If either of the &%-d%&
2661 (debugging) or &%-v%& (verifying) options are set, the daemon does not
2662 disconnect from the controlling terminal. When running this way, it can be
2663 stopped by pressing ctrl-C.
2665 By default, Exim listens for incoming connections to the standard SMTP port on
2666 all the host's running interfaces. However, it is possible to listen on other
2667 ports, on multiple ports, and only on specific interfaces. Chapter
2668 &<<CHAPinterfaces>>& contains a description of the options that control this.
2670 When a listening daemon
2671 .cindex "daemon" "process id (pid)"
2672 .cindex "pid (process id)" "of daemon"
2673 is started without the use of &%-oX%& (that is, without overriding the normal
2674 configuration), it writes its process id to a file called &_exim-daemon.pid_&
2675 in Exim's spool directory. This location can be overridden by setting
2676 PID_FILE_PATH in &_Local/Makefile_&. The file is written while Exim is still
2677 running as root.
2679 When &%-oX%& is used on the command line to start a listening daemon, the
2680 process id is not written to the normal pid file path. However, &%-oP%& can be
2681 used to specify a path on the command line if a pid file is required.
2683 The SIGHUP signal
2684 .cindex "SIGHUP"
2685 .cindex "daemon" "restarting"
2686 can be used to cause the daemon to re-execute itself. This should be done
2687 whenever Exim's configuration file, or any file that is incorporated into it by
2688 means of the &%.include%& facility, is changed, and also whenever a new version
2689 of Exim is installed. It is not necessary to do this when other files that are
2690 referenced from the configuration (for example, alias files) are changed,
2691 because these are reread each time they are used.
2693 .vitem &%-bdf%&
2694 .oindex "&%-bdf%&"
2695 This option has the same effect as &%-bd%& except that it never disconnects
2696 from the controlling terminal, even when no debugging is specified.
2698 .vitem &%-be%&
2699 .oindex "&%-be%&"
2700 .cindex "testing" "string expansion"
2701 .cindex "expansion" "testing"
2702 Run Exim in expansion testing mode. Exim discards its root privilege, to
2703 prevent ordinary users from using this mode to read otherwise inaccessible
2704 files. If no arguments are given, Exim runs interactively, prompting for lines
2705 of data. Otherwise, it processes each argument in turn.
2707 If Exim was built with USE_READLINE=yes in &_Local/Makefile_&, it tries
2708 to load the &%libreadline%& library dynamically whenever the &%-be%& option is
2709 used without command line arguments. If successful, it uses the &[readline()]&
2710 function, which provides extensive line-editing facilities, for reading the
2711 test data. A line history is supported.
2713 Long expansion expressions can be split over several lines by using backslash
2714 continuations. As in Exim's run time configuration, white space at the start of
2715 continuation lines is ignored. Each argument or data line is passed through the
2716 string expansion mechanism, and the result is output. Variable values from the
2717 configuration file (for example, &$qualify_domain$&) are available, but no
2718 message-specific values (such as &$sender_domain$&) are set, because no message
2719 is being processed (but see &%-bem%& and &%-Mset%&).
2721 &*Note*&: If you use this mechanism to test lookups, and you change the data
2722 files or databases you are using, you must exit and restart Exim before trying
2723 the same lookup again. Otherwise, because each Exim process caches the results
2724 of lookups, you will just get the same result as before.
2726 .vitem &%-bem%&&~<&'filename'&>
2727 .oindex "&%-bem%&"
2728 .cindex "testing" "string expansion"
2729 .cindex "expansion" "testing"
2730 This option operates like &%-be%& except that it must be followed by the name
2731 of a file. For example:
2732 .code
2733 exim -bem /tmp/testmessage
2734 .endd
2735 The file is read as a message (as if receiving a locally-submitted non-SMTP
2736 message) before any of the test expansions are done. Thus, message-specific
2737 variables such as &$message_size$& and &$header_from:$& are available. However,
2738 no &'Received:'& header is added to the message. If the &%-t%& option is set,
2739 recipients are read from the headers in the normal way, and are shown in the
2740 &$recipients$& variable. Note that recipients cannot be given on the command
2741 line, because further arguments are taken as strings to expand (just like
2742 &%-be%&).
2744 .vitem &%-bF%&&~<&'filename'&>
2745 .oindex "&%-bF%&"
2746 .cindex "system filter" "testing"
2747 .cindex "testing" "system filter"
2748 This option is the same as &%-bf%& except that it assumes that the filter being
2749 tested is a system filter. The additional commands that are available only in
2750 system filters are recognized.
2752 .vitem &%-bf%&&~<&'filename'&>
2753 .oindex "&%-bf%&"
2754 .cindex "filter" "testing"
2755 .cindex "testing" "filter file"
2756 .cindex "forward file" "testing"
2757 .cindex "testing" "forward file"
2758 .cindex "Sieve filter" "testing"
2759 This option runs Exim in user filter testing mode; the file is the filter file
2760 to be tested, and a test message must be supplied on the standard input. If
2761 there are no message-dependent tests in the filter, an empty file can be
2762 supplied.
2764 If you want to test a system filter file, use &%-bF%& instead of &%-bf%&. You
2765 can use both &%-bF%& and &%-bf%& on the same command, in order to test a system
2766 filter and a user filter in the same run. For example:
2767 .code
2768 exim -bF /system/filter -bf /user/filter </test/message
2769 .endd
2770 This is helpful when the system filter adds header lines or sets filter
2771 variables that are used by the user filter.
2773 If the test filter file does not begin with one of the special lines
2774 .code
2775 # Exim filter
2776 # Sieve filter
2777 .endd
2778 it is taken to be a normal &_.forward_& file, and is tested for validity under
2779 that interpretation. See sections &<<SECTitenonfilred>>& to
2780 &<<SECTspecitredli>>& for a description of the possible contents of non-filter
2781 redirection lists.
2783 The result of an Exim command that uses &%-bf%&, provided no errors are
2784 detected, is a list of the actions that Exim would try to take if presented
2785 with the message for real. More details of filter testing are given in the
2786 separate document entitled &'Exim's interfaces to mail filtering'&.
2788 When testing a filter file,
2789 .cindex "&""From""& line"
2790 .cindex "envelope sender"
2791 .oindex "&%-f%&" "for filter testing"
2792 the envelope sender can be set by the &%-f%& option,
2793 or by a &"From&~"& line at the start of the test message. Various parameters
2794 that would normally be taken from the envelope recipient address of the message
2795 can be set by means of additional command line options (see the next four
2796 options).
2798 .vitem &%-bfd%&&~<&'domain'&>
2799 .oindex "&%-bfd%&"
2800 .vindex "&$qualify_domain$&"
2801 This sets the domain of the recipient address when a filter file is being
2802 tested by means of the &%-bf%& option. The default is the value of
2803 &$qualify_domain$&.
2805 .vitem &%-bfl%&&~<&'local&~part'&>
2806 .oindex "&%-bfl%&"
2807 This sets the local part of the recipient address when a filter file is being
2808 tested by means of the &%-bf%& option. The default is the username of the
2809 process that calls Exim. A local part should be specified with any prefix or
2810 suffix stripped, because that is how it appears to the filter when a message is
2811 actually being delivered.
2813 .vitem &%-bfp%&&~<&'prefix'&>
2814 .oindex "&%-bfp%&"
2815 This sets the prefix of the local part of the recipient address when a filter
2816 file is being tested by means of the &%-bf%& option. The default is an empty
2817 prefix.
2819 .vitem &%-bfs%&&~<&'suffix'&>
2820 .oindex "&%-bfs%&"
2821 This sets the suffix of the local part of the recipient address when a filter
2822 file is being tested by means of the &%-bf%& option. The default is an empty
2823 suffix.
2825 .vitem &%-bh%&&~<&'IP&~address'&>
2826 .oindex "&%-bh%&"
2827 .cindex "testing" "incoming SMTP"
2828 .cindex "SMTP" "testing incoming"
2829 .cindex "testing" "relay control"
2830 .cindex "relaying" "testing configuration"
2831 .cindex "policy control" "testing"
2832 .cindex "debugging" "&%-bh%& option"
2833 This option runs a fake SMTP session as if from the given IP address, using the
2834 standard input and output. The IP address may include a port number at the end,
2835 after a full stop. For example:
2836 .code
2837 exim -bh
2838 exim -bh fe80::a00:20ff:fe86:a061.5678
2839 .endd
2840 When an IPv6 address is given, it is converted into canonical form. In the case
2841 of the second example above, the value of &$sender_host_address$& after
2842 conversion to the canonical form is
2843 &`fe80:0000:0000:0a00:20ff:fe86:a061.5678`&.
2845 Comments as to what is going on are written to the standard error file. These
2846 include lines beginning with &"LOG"& for anything that would have been logged.
2847 This facility is provided for testing configuration options for incoming
2848 messages, to make sure they implement the required policy. For example, you can
2849 test your relay controls using &%-bh%&.
2851 &*Warning 1*&:
2852 .cindex "RFC 1413"
2853 You can test features of the configuration that rely on ident (RFC 1413)
2854 information by using the &%-oMt%& option. However, Exim cannot actually perform
2855 an ident callout when testing using &%-bh%& because there is no incoming SMTP
2856 connection.
2858 &*Warning 2*&: Address verification callouts (see section &<<SECTcallver>>&)
2859 are also skipped when testing using &%-bh%&. If you want these callouts to
2860 occur, use &%-bhc%& instead.
2862 Messages supplied during the testing session are discarded, and nothing is
2863 written to any of the real log files. There may be pauses when DNS (and other)
2864 lookups are taking place, and of course these may time out. The &%-oMi%& option
2865 can be used to specify a specific IP interface and port if this is important,
2866 and &%-oMaa%& and &%-oMai%& can be used to set parameters as if the SMTP
2867 session were authenticated.
2869 The &'exim_checkaccess'& utility is a &"packaged"& version of &%-bh%& whose
2870 output just states whether a given recipient address from a given host is
2871 acceptable or not. See section &<<SECTcheckaccess>>&.
2873 Features such as authentication and encryption, where the client input is not
2874 plain text, cannot easily be tested with &%-bh%&. Instead, you should use a
2875 specialized SMTP test program such as
2876 &url(http://jetmore.org/john/code/#swaks,swaks).
2878 .vitem &%-bhc%&&~<&'IP&~address'&>
2879 .oindex "&%-bhc%&"
2880 This option operates in the same way as &%-bh%&, except that address
2881 verification callouts are performed if required. This includes consulting and
2882 updating the callout cache database.
2884 .vitem &%-bi%&
2885 .oindex "&%-bi%&"
2886 .cindex "alias file" "building"
2887 .cindex "building alias file"
2888 .cindex "Sendmail compatibility" "&%-bi%& option"
2889 Sendmail interprets the &%-bi%& option as a request to rebuild its alias file.
2890 Exim does not have the concept of a single alias file, and so it cannot mimic
2891 this behaviour. However, calls to &_/usr/lib/sendmail_& with the &%-bi%& option
2892 tend to appear in various scripts such as NIS make files, so the option must be
2893 recognized.
2895 If &%-bi%& is encountered, the command specified by the &%bi_command%&
2896 configuration option is run, under the uid and gid of the caller of Exim. If
2897 the &%-oA%& option is used, its value is passed to the command as an argument.
2898 The command set by &%bi_command%& may not contain arguments. The command can
2899 use the &'exim_dbmbuild'& utility, or some other means, to rebuild alias files
2900 if this is required. If the &%bi_command%& option is not set, calling Exim with
2901 &%-bi%& is a no-op.
2903 .vitem &%-bm%&
2904 .oindex "&%-bm%&"
2905 .cindex "local message reception"
2906 This option runs an Exim receiving process that accepts an incoming,
2907 locally-generated message on the current input. The recipients are given as the
2908 command arguments (except when &%-t%& is also present &-- see below). Each
2909 argument can be a comma-separated list of RFC 2822 addresses. This is the
2910 default option for selecting the overall action of an Exim call; it is assumed
2911 if no other conflicting option is present.
2913 If any addresses in the message are unqualified (have no domain), they are
2914 qualified by the values of the &%qualify_domain%& or &%qualify_recipient%&
2915 options, as appropriate. The &%-bnq%& option (see below) provides a way of
2916 suppressing this for special cases.
2918 Policy checks on the contents of local messages can be enforced by means of
2919 the non-SMTP ACL. See chapter &<<CHAPACL>>& for details.
2921 .cindex "return code" "for &%-bm%&"
2922 The return code is zero if the message is successfully accepted. Otherwise, the
2923 action is controlled by the &%-oe%&&'x'& option setting &-- see below.
2925 The format
2926 .cindex "message" "format"
2927 .cindex "format" "message"
2928 .cindex "&""From""& line"
2929 .cindex "UUCP" "&""From""& line"
2930 .cindex "Sendmail compatibility" "&""From""& line"
2931 of the message must be as defined in RFC 2822, except that, for
2932 compatibility with Sendmail and Smail, a line in one of the forms
2933 .code
2934 From sender Fri Jan 5 12:55 GMT 1997
2935 From sender Fri, 5 Jan 97 12:55:01
2936 .endd
2937 (with the weekday optional, and possibly with additional text after the date)
2938 is permitted to appear at the start of the message. There appears to be no
2939 authoritative specification of the format of this line. Exim recognizes it by
2940 matching against the regular expression defined by the &%uucp_from_pattern%&
2941 option, which can be changed if necessary.
2943 .oindex "&%-f%&" "overriding &""From""& line"
2944 The specified sender is treated as if it were given as the argument to the
2945 &%-f%& option, but if a &%-f%& option is also present, its argument is used in
2946 preference to the address taken from the message. The caller of Exim must be a
2947 trusted user for the sender of a message to be set in this way.
2949 .vitem &%-bnq%&
2950 .oindex "&%-bnq%&"
2951 .cindex "address qualification, suppressing"
2952 By default, Exim automatically qualifies unqualified addresses (those
2953 without domains) that appear in messages that are submitted locally (that
2954 is, not over TCP/IP). This qualification applies both to addresses in
2955 envelopes, and addresses in header lines. Sender addresses are qualified using
2956 &%qualify_domain%&, and recipient addresses using &%qualify_recipient%& (which
2957 defaults to the value of &%qualify_domain%&).
2959 Sometimes, qualification is not wanted. For example, if &%-bS%& (batch SMTP) is
2960 being used to re-submit messages that originally came from remote hosts after
2961 content scanning, you probably do not want to qualify unqualified addresses in
2962 header lines. (Such lines will be present only if you have not enabled a header
2963 syntax check in the appropriate ACL.)
2965 The &%-bnq%& option suppresses all qualification of unqualified addresses in
2966 messages that originate on the local host. When this is used, unqualified
2967 addresses in the envelope provoke errors (causing message rejection) and
2968 unqualified addresses in header lines are left alone.
2971 .vitem &%-bP%&
2972 .oindex "&%-bP%&"
2973 .cindex "configuration options" "extracting"
2974 .cindex "options" "configuration &-- extracting"
2975 If this option is given with no arguments, it causes the values of all Exim's
2976 main configuration options to be written to the standard output. The values
2977 of one or more specific options can be requested by giving their names as
2978 arguments, for example:
2979 .code
2980 exim -bP qualify_domain hold_domains
2981 .endd
2982 .cindex "hiding configuration option values"
2983 .cindex "configuration options" "hiding value of"
2984 .cindex "options" "hiding value of"
2985 However, any option setting that is preceded by the word &"hide"& in the
2986 configuration file is not shown in full, except to an admin user. For other
2987 users, the output is as in this example:
2988 .code
2989 mysql_servers = <value not displayable>
2990 .endd
2991 If &%configure_file%& is given as an argument, the name of the run time
2992 configuration file is output.
2993 If a list of configuration files was supplied, the value that is output here
2994 is the name of the file that was actually used.
2996 .cindex "daemon" "process id (pid)"
2997 .cindex "pid (process id)" "of daemon"
2998 If &%log_file_path%& or &%pid_file_path%& are given, the names of the
2999 directories where log files and daemon pid files are written are output,
3000 respectively. If these values are unset, log files are written in a
3001 sub-directory of the spool directory called &%log%&, and the pid file is
3002 written directly into the spool directory.
3004 If &%-bP%& is followed by a name preceded by &`+`&, for example,
3005 .code
3006 exim -bP +local_domains
3007 .endd
3008 it searches for a matching named list of any type (domain, host, address, or
3009 local part) and outputs what it finds.
3011 .cindex "options" "router &-- extracting"
3012 .cindex "options" "transport &-- extracting"
3013 .cindex "options" "authenticator &-- extracting"
3014 If one of the words &%router%&, &%transport%&, or &%authenticator%& is given,
3015 followed by the name of an appropriate driver instance, the option settings for
3016 that driver are output. For example:
3017 .code
3018 exim -bP transport local_delivery
3019 .endd
3020 The generic driver options are output first, followed by the driver's private
3021 options. A list of the names of drivers of a particular type can be obtained by
3022 using one of the words &%router_list%&, &%transport_list%&, or
3023 &%authenticator_list%&, and a complete list of all drivers with their option
3024 settings can be obtained by using &%routers%&, &%transports%&, or
3025 &%authenticators%&.
3027 .cindex "options" "macro &-- extracting"
3028 If invoked by an admin user, then &%macro%&, &%macro_list%& and &%macros%&
3029 are available, similarly to the drivers. Because macros are sometimes used
3030 for storing passwords, this option is restricted.
3031 The output format is one item per line.
3033 .vitem &%-bp%&
3034 .oindex "&%-bp%&"
3035 .cindex "queue" "listing messages on"
3036 .cindex "listing" "messages on the queue"
3037 This option requests a listing of the contents of the mail queue on the
3038 standard output. If the &%-bp%& option is followed by a list of message ids,
3039 just those messages are listed. By default, this option can be used only by an
3040 admin user. However, the &%queue_list_requires_admin%& option can be set false
3041 to allow any user to see the queue.
3043 Each message on the queue is displayed as in the following example:
3044 .code
3045 25m 2.9K 0t5C6f-0000c8-00 <alice@wonderland.fict.example>
3046 red.king@looking-glass.fict.example
3047 <other addresses>
3048 .endd
3049 .cindex "message" "size in queue listing"
3050 .cindex "size" "of message"
3051 The first line contains the length of time the message has been on the queue
3052 (in this case 25 minutes), the size of the message (2.9K), the unique local
3053 identifier for the message, and the message sender, as contained in the
3054 envelope. For bounce messages, the sender address is empty, and appears as
3055 &"<>"&. If the message was submitted locally by an untrusted user who overrode
3056 the default sender address, the user's login name is shown in parentheses
3057 before the sender address.
3059 .cindex "frozen messages" "in queue listing"
3060 If the message is frozen (attempts to deliver it are suspended) then the text
3061 &"*** frozen ***"& is displayed at the end of this line.
3063 The recipients of the message (taken from the envelope, not the headers) are
3064 displayed on subsequent lines. Those addresses to which the message has already
3065 been delivered are marked with the letter D. If an original address gets
3066 expanded into several addresses via an alias or forward file, the original is
3067 displayed with a D only when deliveries for all of its child addresses are
3068 complete.
3071 .vitem &%-bpa%&
3072 .oindex "&%-bpa%&"
3073 This option operates like &%-bp%&, but in addition it shows delivered addresses
3074 that were generated from the original top level address(es) in each message by
3075 alias or forwarding operations. These addresses are flagged with &"+D"& instead
3076 of just &"D"&.
3079 .vitem &%-bpc%&
3080 .oindex "&%-bpc%&"
3081 .cindex "queue" "count of messages on"
3082 This option counts the number of messages on the queue, and writes the total
3083 to the standard output. It is restricted to admin users, unless
3084 &%queue_list_requires_admin%& is set false.
3087 .vitem &%-bpr%&
3088 .oindex "&%-bpr%&"
3089 This option operates like &%-bp%&, but the output is not sorted into
3090 chronological order of message arrival. This can speed it up when there are
3091 lots of messages on the queue, and is particularly useful if the output is
3092 going to be post-processed in a way that doesn't need the sorting.
3094 .vitem &%-bpra%&
3095 .oindex "&%-bpra%&"
3096 This option is a combination of &%-bpr%& and &%-bpa%&.
3098 .vitem &%-bpru%&
3099 .oindex "&%-bpru%&"
3100 This option is a combination of &%-bpr%& and &%-bpu%&.
3103 .vitem &%-bpu%&
3104 .oindex "&%-bpu%&"
3105 This option operates like &%-bp%& but shows only undelivered top-level
3106 addresses for each message displayed. Addresses generated by aliasing or
3107 forwarding are not shown, unless the message was deferred after processing by a
3108 router with the &%one_time%& option set.
3111 .vitem &%-brt%&
3112 .oindex "&%-brt%&"
3113 .cindex "testing" "retry configuration"
3114 .cindex "retry" "configuration testing"
3115 This option is for testing retry rules, and it must be followed by up to three
3116 arguments. It causes Exim to look for a retry rule that matches the values
3117 and to write it to the standard output. For example:
3118 .code
3119 exim -brt bach.comp.mus.example
3120 Retry rule: *.comp.mus.example F,2h,15m; F,4d,30m;
3121 .endd
3122 See chapter &<<CHAPretry>>& for a description of Exim's retry rules. The first
3123 argument, which is required, can be a complete address in the form
3124 &'local_part@domain'&, or it can be just a domain name. If the second argument
3125 contains a dot, it is interpreted as an optional second domain name; if no
3126 retry rule is found for the first argument, the second is tried. This ties in
3127 with Exim's behaviour when looking for retry rules for remote hosts &-- if no
3128 rule is found that matches the host, one that matches the mail domain is
3129 sought. Finally, an argument that is the name of a specific delivery error, as
3130 used in setting up retry rules, can be given. For example:
3131 .code
3132 exim -brt haydn.comp.mus.example quota_3d
3133 Retry rule: *@haydn.comp.mus.example quota_3d F,1h,15m
3134 .endd
3136 .vitem &%-brw%&
3137 .oindex "&%-brw%&"
3138 .cindex "testing" "rewriting"
3139 .cindex "rewriting" "testing"
3140 This option is for testing address rewriting rules, and it must be followed by
3141 a single argument, consisting of either a local part without a domain, or a
3142 complete address with a fully qualified domain. Exim outputs how this address
3143 would be rewritten for each possible place it might appear. See chapter
3144 &<<CHAPrewrite>>& for further details.
3146 .vitem &%-bS%&
3147 .oindex "&%-bS%&"
3148 .cindex "SMTP" "batched incoming"
3149 .cindex "batched SMTP input"
3150 This option is used for batched SMTP input, which is an alternative interface
3151 for non-interactive local message submission. A number of messages can be
3152 submitted in a single run. However, despite its name, this is not really SMTP
3153 input. Exim reads each message's envelope from SMTP commands on the standard
3154 input, but generates no responses. If the caller is trusted, or
3155 &%untrusted_set_sender%& is set, the senders in the SMTP MAIL commands are
3156 believed; otherwise the sender is always the caller of Exim.
3158 The message itself is read from the standard input, in SMTP format (leading
3159 dots doubled), terminated by a line containing just a single dot. An error is
3160 provoked if the terminating dot is missing. A further message may then follow.
3162 As for other local message submissions, the contents of incoming batch SMTP
3163 messages can be checked using the non-SMTP ACL (see chapter &<<CHAPACL>>&).
3164 Unqualified addresses are automatically qualified using &%qualify_domain%& and
3165 &%qualify_recipient%&, as appropriate, unless the &%-bnq%& option is used.
3167 Some other SMTP commands are recognized in the input. HELO and EHLO act
3168 as RSET; VRFY, EXPN, ETRN, and HELP act as NOOP;
3169 QUIT quits, ignoring the rest of the standard input.
3171 .cindex "return code" "for &%-bS%&"
3172 If any error is encountered, reports are written to the standard output and
3173 error streams, and Exim gives up immediately. The return code is 0 if no error
3174 was detected; it is 1 if one or more messages were accepted before the error
3175 was detected; otherwise it is 2.
3177 More details of input using batched SMTP are given in section
3178 &<<SECTincomingbatchedSMTP>>&.
3180 .vitem &%-bs%&
3181 .oindex "&%-bs%&"
3182 .cindex "SMTP" "local input"
3183 .cindex "local SMTP input"
3184 This option causes Exim to accept one or more messages by reading SMTP commands
3185 on the standard input, and producing SMTP replies on the standard output. SMTP
3186 policy controls, as defined in ACLs (see chapter &<<CHAPACL>>&) are applied.
3187 Some user agents use this interface as a way of passing locally-generated
3188 messages to the MTA.
3190 In
3191 .cindex "sender" "source of"
3192 this usage, if the caller of Exim is trusted, or &%untrusted_set_sender%& is
3193 set, the senders of messages are taken from the SMTP MAIL commands.
3194 Otherwise the content of these commands is ignored and the sender is set up as
3195 the calling user. Unqualified addresses are automatically qualified using
3196 &%qualify_domain%& and &%qualify_recipient%&, as appropriate, unless the
3197 &%-bnq%& option is used.
3199 .cindex "inetd"
3200 The
3201 &%-bs%& option is also used to run Exim from &'inetd'&, as an alternative to
3202 using a listening daemon. Exim can distinguish the two cases by checking
3203 whether the standard input is a TCP/IP socket. When Exim is called from
3204 &'inetd'&, the source of the mail is assumed to be remote, and the comments
3205 above concerning senders and qualification do not apply. In this situation,
3206 Exim behaves in exactly the same way as it does when receiving a message via
3207 the listening daemon.
3209 .vitem &%-bmalware%&&~<&'filename'&>
3210 .oindex "&%-bmalware%&"
3211 .cindex "testing", "malware"
3212 .cindex "malware scan test"
3213 This debugging option causes Exim to scan the given file,
3214 using the malware scanning framework. The option of &%av_scanner%& influences
3215 this option, so if &%av_scanner%&'s value is dependent upon an expansion then
3216 the expansion should have defaults which apply to this invocation. ACLs are
3217 not invoked, so if &%av_scanner%& references an ACL variable then that variable
3218 will never be populated and &%-bmalware%& will fail.
3220 Exim will have changed working directory before resolving the filename, so
3221 using fully qualified pathnames is advisable. Exim will be running as the Exim
3222 user when it tries to open the file, rather than as the invoking user.
3223 This option requires admin privileges.
3225 The &%-bmalware%& option will not be extended to be more generally useful,
3226 there are better tools for file-scanning. This option exists to help
3227 administrators verify their Exim and AV scanner configuration.
3229 .vitem &%-bt%&
3230 .oindex "&%-bt%&"
3231 .cindex "testing" "addresses"
3232 .cindex "address" "testing"
3233 This option runs Exim in address testing mode, in which each argument is taken
3234 as a recipient address to be tested for deliverability. The results are
3235 written to the standard output. If a test fails, and the caller is not an admin
3236 user, no details of the failure are output, because these might contain
3237 sensitive information such as usernames and passwords for database lookups.
3239 If no arguments are given, Exim runs in an interactive manner, prompting with a
3240 right angle bracket for addresses to be tested.
3242 Unlike the &%-be%& test option, you cannot arrange for Exim to use the
3243 &[readline()]& function, because it is running as &'root'& and there are
3244 security issues.
3246 Each address is handled as if it were the recipient address of a message
3247 (compare the &%-bv%& option). It is passed to the routers and the result is
3248 written to the standard output. However, any router that has
3249 &%no_address_test%& set is bypassed. This can make &%-bt%& easier to use for
3250 genuine routing tests if your first router passes everything to a scanner
3251 program.
3253 .cindex "return code" "for &%-bt%&"
3254 The return code is 2 if any address failed outright; it is 1 if no address
3255 failed outright but at least one could not be resolved for some reason. Return
3256 code 0 is given only when all addresses succeed.
3258 .cindex "duplicate addresses"
3259 &*Note*&: When actually delivering a message, Exim removes duplicate recipient
3260 addresses after routing is complete, so that only one delivery takes place.
3261 This does not happen when testing with &%-bt%&; the full results of routing are
3262 always shown.
3264 &*Warning*&: &%-bt%& can only do relatively simple testing. If any of the
3265 routers in the configuration makes any tests on the sender address of a
3266 message,
3267 .oindex "&%-f%&" "for address testing"
3268 you can use the &%-f%& option to set an appropriate sender when running
3269 &%-bt%& tests. Without it, the sender is assumed to be the calling user at the
3270 default qualifying domain. However, if you have set up (for example) routers
3271 whose behaviour depends on the contents of an incoming message, you cannot test
3272 those conditions using &%-bt%&. The &%-N%& option provides a possible way of
3273 doing such tests.
3275 .vitem &%-bV%&
3276 .oindex "&%-bV%&"
3277 .cindex "version number of Exim"
3278 This option causes Exim to write the current version number, compilation
3279 number, and compilation date of the &'exim'& binary to the standard output.
3280 It also lists the DBM library that is being used, the optional modules (such as
3281 specific lookup types), the drivers that are included in the binary, and the
3282 name of the run time configuration file that is in use.
3284 As part of its operation, &%-bV%& causes Exim to read and syntax check its
3285 configuration file. However, this is a static check only. It cannot check
3286 values that are to be expanded. For example, although a misspelt ACL verb is
3287 detected, an error in the verb's arguments is not. You cannot rely on &%-bV%&
3288 alone to discover (for example) all the typos in the configuration; some
3289 realistic testing is needed. The &%-bh%& and &%-N%& options provide more
3290 dynamic testing facilities.
3292 .vitem &%-bv%&
3293 .oindex "&%-bv%&"
3294 .cindex "verifying address" "using &%-bv%&"
3295 .cindex "address" "verification"
3296 This option runs Exim in address verification mode, in which each argument is
3297 taken as a recipient address to be verified by the routers. (This does
3298 not involve any verification callouts). During normal operation, verification
3299 happens mostly as a consequence processing a &%verify%& condition in an ACL
3300 (see chapter &<<CHAPACL>>&). If you want to test an entire ACL, possibly
3301 including callouts, see the &%-bh%& and &%-bhc%& options.
3303 If verification fails, and the caller is not an admin user, no details of the
3304 failure are output, because these might contain sensitive information such as
3305 usernames and passwords for database lookups.
3307 If no arguments are given, Exim runs in an interactive manner, prompting with a
3308 right angle bracket for addresses to be verified.
3310 Unlike the &%-be%& test option, you cannot arrange for Exim to use the
3311 &[readline()]& function, because it is running as &'exim'& and there are
3312 security issues.
3314 Verification differs from address testing (the &%-bt%& option) in that routers
3315 that have &%no_verify%& set are skipped, and if the address is accepted by a
3316 router that has &%fail_verify%& set, verification fails. The address is
3317 verified as a recipient if &%-bv%& is used; to test verification for a sender
3318 address, &%-bvs%& should be used.
3320 If the &%-v%& option is not set, the output consists of a single line for each
3321 address, stating whether it was verified or not, and giving a reason in the
3322 latter case. Without &%-v%&, generating more than one address by redirection
3323 causes verification to end successfully, without considering the generated
3324 addresses. However, if just one address is generated, processing continues,
3325 and the generated address must verify successfully for the overall verification
3326 to succeed.
3328 When &%-v%& is set, more details are given of how the address has been handled,
3329 and in the case of address redirection, all the generated addresses are also
3330 considered. Verification may succeed for some and fail for others.
3332 The
3333 .cindex "return code" "for &%-bv%&"
3334 return code is 2 if any address failed outright; it is 1 if no address
3335 failed outright but at least one could not be resolved for some reason. Return
3336 code 0 is given only when all addresses succeed.
3338 If any of the routers in the configuration makes any tests on the sender
3339 address of a message, you should use the &%-f%& option to set an appropriate
3340 sender when running &%-bv%& tests. Without it, the sender is assumed to be the
3341 calling user at the default qualifying domain.
3343 .vitem &%-bvs%&
3344 .oindex "&%-bvs%&"
3345 This option acts like &%-bv%&, but verifies the address as a sender rather
3346 than a recipient address. This affects any rewriting and qualification that
3347 might happen.
3349 .vitem &%-C%&&~<&'filelist'&>
3350 .oindex "&%-C%&"
3351 .cindex "configuration file" "alternate"
3352 .cindex "CONFIGURE_FILE"
3353 .cindex "alternate configuration file"
3354 This option causes Exim to find the run time configuration file from the given
3355 list instead of from the list specified by the CONFIGURE_FILE
3356 compile-time setting. Usually, the list will consist of just a single file
3357 name, but it can be a colon-separated list of names. In this case, the first
3358 file that exists is used. Failure to open an existing file stops Exim from
3359 proceeding any further along the list, and an error is generated.
3361 When this option is used by a caller other than root, and the list is different
3362 from the compiled-in list, Exim gives up its root privilege immediately, and
3363 runs with the real and effective uid and gid set to those of the caller.
3364 However, if a TRUSTED_CONFIG_LIST file is defined in &_Local/Makefile_&, that
3365 file contains a list of full pathnames, one per line, for configuration files
3366 which are trusted. Root privilege is retained for any configuration file so
3367 listed, as long as the caller is the Exim user (or the user specified in the
3368 CONFIGURE_OWNER option, if any), and as long as the configuration file is
3369 not writeable by inappropriate users or groups.
3371 Leaving TRUSTED_CONFIG_LIST unset precludes the possibility of testing a
3372 configuration using &%-C%& right through message reception and delivery,
3373 even if the caller is root. The reception works, but by that time, Exim is
3374 running as the Exim user, so when it re-executes to regain privilege for the
3375 delivery, the use of &%-C%& causes privilege to be lost. However, root can
3376 test reception and delivery using two separate commands (one to put a message
3377 on the queue, using &%-odq%&, and another to do the delivery, using &%-M%&).
3379 If ALT_CONFIG_PREFIX is defined &_in Local/Makefile_&, it specifies a
3380 prefix string with which any file named in a &%-C%& command line option
3381 must start. In addition, the file name must not contain the sequence &`/../`&.
3382 However, if the value of the &%-C%& option is identical to the value of
3383 CONFIGURE_FILE in &_Local/Makefile_&, Exim ignores &%-C%& and proceeds as
3384 usual. There is no default setting for ALT_CONFIG_PREFIX; when it is
3385 unset, any file name can be used with &%-C%&.
3387 ALT_CONFIG_PREFIX can be used to confine alternative configuration files
3388 to a directory to which only root has access. This prevents someone who has
3389 broken into the Exim account from running a privileged Exim with an arbitrary
3390 configuration file.
3392 The &%-C%& facility is useful for ensuring that configuration files are
3393 syntactically correct, but cannot be used for test deliveries, unless the
3394 caller is privileged, or unless it is an exotic configuration that does not
3395 require privilege. No check is made on the owner or group of the files
3396 specified by this option.
3399 .vitem &%-D%&<&'macro'&>=<&'value'&>
3400 .oindex "&%-D%&"
3401 .cindex "macro" "setting on command line"
3402 This option can be used to override macro definitions in the configuration file
3403 (see section &<<SECTmacrodefs>>&). However, like &%-C%&, if it is used by an
3404 unprivileged caller, it causes Exim to give up its root privilege.
3405 If DISABLE_D_OPTION is defined in &_Local/Makefile_&, the use of &%-D%& is
3406 completely disabled, and its use causes an immediate error exit.
3408 If WHITELIST_D_MACROS is defined in &_Local/Makefile_& then it should be a
3409 colon-separated list of macros which are considered safe and, if &%-D%& only
3410 supplies macros from this list, and the values are acceptable, then Exim will
3411 not give up root privilege if the caller is root, the Exim run-time user, or
3412 the CONFIGURE_OWNER, if set. This is a transition mechanism and is expected
3413 to be removed in the future. Acceptable values for the macros satisfy the
3414 regexp: &`^[A-Za-z0-9_/.-]*$`&
3416 The entire option (including equals sign if present) must all be within one
3417 command line item. &%-D%& can be used to set the value of a macro to the empty
3418 string, in which case the equals sign is optional. These two commands are
3419 synonymous:
3420 .code
3421 exim -DABC ...
3422 exim -DABC= ...
3423 .endd
3424 To include spaces in a macro definition item, quotes must be used. If you use
3425 quotes, spaces are permitted around the macro name and the equals sign. For
3426 example:
3427 .code
3428 exim '-D ABC = something' ...
3429 .endd
3430 &%-D%& may be repeated up to 10 times on a command line.
3433 .vitem &%-d%&<&'debug&~options'&>
3434 .oindex "&%-d%&"
3435 .cindex "debugging" "list of selectors"
3436 .cindex "debugging" "&%-d%& option"
3437 This option causes debugging information to be written to the standard
3438 error stream. It is restricted to admin users because debugging output may show
3439 database queries that contain password information. Also, the details of users'
3440 filter files should be protected. If a non-admin user uses &%-d%&, Exim
3441 writes an error message to the standard error stream and exits with a non-zero
3442 return code.
3444 When &%-d%& is used, &%-v%& is assumed. If &%-d%& is given on its own, a lot of
3445 standard debugging data is output. This can be reduced, or increased to include
3446 some more rarely needed information, by directly following &%-d%& with a string
3447 made up of names preceded by plus or minus characters. These add or remove sets
3448 of debugging data, respectively. For example, &%-d+filter%& adds filter
3449 debugging, whereas &%-d-all+filter%& selects only filter debugging. Note that
3450 no spaces are allowed in the debug setting. The available debugging categories
3451 are:
3452 .display
3453 &`acl `& ACL interpretation
3454 &`auth `& authenticators
3455 &`deliver `& general delivery logic
3456 &`dns `& DNS lookups (see also resolver)
3457 &`dnsbl `& DNS black list (aka RBL) code
3458 &`exec `& arguments for &[execv()]& calls
3459 &`expand `& detailed debugging for string expansions
3460 &`filter `& filter handling
3461 &`hints_lookup `& hints data lookups
3462 &`host_lookup `& all types of name-to-IP address handling
3463 &`ident `& ident lookup
3464 &`interface `& lists of local interfaces
3465 &`lists `& matching things in lists
3466 &`load `& system load checks
3467 &`local_scan `& can be used by &[local_scan()]& (see chapter &&&
3468 &<<CHAPlocalscan>>&)
3469 &`lookup `& general lookup code and all lookups
3470 &`memory `& memory handling
3471 &`pid `& add pid to debug output lines
3472 &`process_info `& setting info for the process log
3473 &`queue_run `& queue runs
3474 &`receive `& general message reception logic
3475 &`resolver `& turn on the DNS resolver's debugging output
3476 &`retry `& retry handling
3477 &`rewrite `& address rewriting
3478 &`route `& address routing
3479 &`timestamp `& add timestamp to debug output lines
3480 &`tls `& TLS logic
3481 &`transport `& transports
3482 &`uid `& changes of uid/gid and looking up uid/gid
3483 &`verify `& address verification logic
3484 &`all `& almost all of the above (see below), and also &%-v%&
3485 .endd
3486 The &`all`& option excludes &`memory`& when used as &`+all`&, but includes it
3487 for &`-all`&. The reason for this is that &`+all`& is something that people
3488 tend to use when generating debug output for Exim maintainers. If &`+memory`&
3489 is included, an awful lot of output that is very rarely of interest is
3490 generated, so it now has to be explicitly requested. However, &`-all`& does
3491 turn everything off.
3493 .cindex "resolver, debugging output"
3494 .cindex "DNS resolver, debugging output"
3495 The &`resolver`& option produces output only if the DNS resolver was compiled
3496 with DEBUG enabled. This is not the case in some operating systems. Also,
3497 unfortunately, debugging output from the DNS resolver is written to stdout
3498 rather than stderr.
3500 The default (&%-d%& with no argument) omits &`expand`&, &`filter`&,
3501 &`interface`&, &`load`&, &`memory`&, &`pid`&, &`resolver`&, and &`timestamp`&.
3502 However, the &`pid`& selector is forced when debugging is turned on for a
3503 daemon, which then passes it on to any re-executed Exims. Exim also
3504 automatically adds the pid to debug lines when several remote deliveries are
3505 run in parallel.
3507 The &`timestamp`& selector causes the current time to be inserted at the start
3508 of all debug output lines. This can be useful when trying to track down delays
3509 in processing.
3511 If the &%debug_print%& option is set in any driver, it produces output whenever
3512 any debugging is selected, or if &%-v%& is used.
3514 .vitem &%-dd%&<&'debug&~options'&>
3515 .oindex "&%-dd%&"
3516 This option behaves exactly like &%-d%& except when used on a command that
3517 starts a daemon process. In that case, debugging is turned off for the
3518 subprocesses that the daemon creates. Thus, it is useful for monitoring the
3519 behaviour of the daemon without creating as much output as full debugging does.
3521 .vitem &%-dropcr%&
3522 .oindex "&%-dropcr%&"
3523 This is an obsolete option that is now a no-op. It used to affect the way Exim
3524 handled CR and LF characters in incoming messages. What happens now is
3525 described in section &<<SECTlineendings>>&.
3527 .vitem &%-E%&
3528 .oindex "&%-E%&"
3529 .cindex "bounce message" "generating"
3530 This option specifies that an incoming message is a locally-generated delivery
3531 failure report. It is used internally by Exim when handling delivery failures
3532 and is not intended for external use. Its only effect is to stop Exim
3533 generating certain messages to the postmaster, as otherwise message cascades
3534 could occur in some situations. As part of the same option, a message id may
3535 follow the characters &%-E%&. If it does, the log entry for the receipt of the
3536 new message contains the id, following &"R="&, as a cross-reference.
3538 .vitem &%-e%&&'x'&
3539 .oindex "&%-e%&&'x'&"
3540 There are a number of Sendmail options starting with &%-oe%& which seem to be
3541 called by various programs without the leading &%o%& in the option. For
3542 example, the &%vacation%& program uses &%-eq%&. Exim treats all options of the
3543 form &%-e%&&'x'& as synonymous with the corresponding &%-oe%&&'x'& options.
3545 .vitem &%-F%&&~<&'string'&>
3546 .oindex "&%-F%&"
3547 .cindex "sender" "name"
3548 .cindex "name" "of sender"
3549 This option sets the sender's full name for use when a locally-generated
3550 message is being accepted. In the absence of this option, the user's &'gecos'&
3551 entry from the password data is used. As users are generally permitted to alter
3552 their &'gecos'& entries, no security considerations are involved. White space
3553 between &%-F%& and the <&'string'&> is optional.
3555 .vitem &%-f%&&~<&'address'&>
3556 .oindex "&%-f%&"
3557 .cindex "sender" "address"
3558 .cindex "address" "sender"
3559 .cindex "trusted users"
3560 .cindex "envelope sender"
3561 .cindex "user" "trusted"
3562 This option sets the address of the envelope sender of a locally-generated
3563 message (also known as the return path). The option can normally be used only
3564 by a trusted user, but &%untrusted_set_sender%& can be set to allow untrusted
3565 users to use it.
3567 Processes running as root or the Exim user are always trusted. Other
3568 trusted users are defined by the &%trusted_users%& or &%trusted_groups%&
3569 options. In the absence of &%-f%&, or if the caller is not trusted, the sender
3570 of a local message is set to the caller's login name at the default qualify
3571 domain.
3573 There is one exception to the restriction on the use of &%-f%&: an empty sender
3574 can be specified by any user, trusted or not, to create a message that can
3575 never provoke a bounce. An empty sender can be specified either as an empty
3576 string, or as a pair of angle brackets with nothing between them, as in these
3577 examples of shell commands:
3578 .code
3579 exim -f '<>' user@domain
3580 exim -f "" user@domain
3581 .endd
3582 In addition, the use of &%-f%& is not restricted when testing a filter file
3583 with &%-bf%& or when testing or verifying addresses using the &%-bt%& or
3584 &%-bv%& options.
3586 Allowing untrusted users to change the sender address does not of itself make
3587 it possible to send anonymous mail. Exim still checks that the &'From:'& header
3588 refers to the local user, and if it does not, it adds a &'Sender:'& header,
3589 though this can be overridden by setting &%no_local_from_check%&.
3591 White
3592 .cindex "&""From""& line"
3593 space between &%-f%& and the <&'address'&> is optional (that is, they can be
3594 given as two arguments or one combined argument). The sender of a
3595 locally-generated message can also be set (when permitted) by an initial
3596 &"From&~"& line in the message &-- see the description of &%-bm%& above &-- but
3597 if &%-f%& is also present, it overrides &"From&~"&.
3599 .vitem &%-G%&
3600 .oindex "&%-G%&"
3601 .cindex "Sendmail compatibility" "&%-G%& option ignored"
3602 This is a Sendmail option which is ignored by Exim.
3604 .vitem &%-h%&&~<&'number'&>
3605 .oindex "&%-h%&"
3606 .cindex "Sendmail compatibility" "&%-h%& option ignored"
3607 This option is accepted for compatibility with Sendmail, but has no effect. (In
3608 Sendmail it overrides the &"hop count"& obtained by counting &'Received:'&
3609 headers.)
3611 .vitem &%-i%&
3612 .oindex "&%-i%&"
3613 .cindex "Solaris" "&'mail'& command"
3614 .cindex "dot" "in incoming non-SMTP message"
3615 This option, which has the same effect as &%-oi%&, specifies that a dot on a
3616 line by itself should not terminate an incoming, non-SMTP message. I can find
3617 no documentation for this option in Solaris 2.4 Sendmail, but the &'mailx'&
3618 command in Solaris 2.4 uses it. See also &%-ti%&.
3620 .vitem &%-M%&&~<&'message&~id'&>&~<&'message&~id'&>&~...
3621 .oindex "&%-M%&"
3622 .cindex "forcing delivery"
3623 .cindex "delivery" "forcing attempt"
3624 .cindex "frozen messages" "forcing delivery"
3625 This option requests Exim to run a delivery attempt on each message in turn. If
3626 any of the messages are frozen, they are automatically thawed before the
3627 delivery attempt. The settings of &%queue_domains%&, &%queue_smtp_domains%&,
3628 and &%hold_domains%& are ignored.
3630 Retry
3631 .cindex "hints database" "overriding retry hints"
3632 hints for any of the addresses are overridden &-- Exim tries to deliver even if
3633 the normal retry time has not yet been reached. This option requires the caller
3634 to be an admin user. However, there is an option called &%prod_requires_admin%&
3635 which can be set false to relax this restriction (and also the same requirement
3636 for the &%-q%&, &%-R%&, and &%-S%& options).
3638 The deliveries happen synchronously, that is, the original Exim process does
3639 not terminate until all the delivery attempts have finished. No output is
3640 produced unless there is a serious error. If you want to see what is happening,
3641 use the &%-v%& option as well, or inspect Exim's main log.
3643 .vitem &%-Mar%&&~<&'message&~id'&>&~<&'address'&>&~<&'address'&>&~...
3644 .oindex "&%-Mar%&"
3645 .cindex "message" "adding recipients"
3646 .cindex "recipient" "adding"
3647 This option requests Exim to add the addresses to the list of recipients of the
3648 message (&"ar"& for &"add recipients"&). The first argument must be a message
3649 id, and the remaining ones must be email addresses. However, if the message is
3650 active (in the middle of a delivery attempt), it is not altered. This option
3651 can be used only by an admin user.
3653 .vitem "&%-MC%&&~<&'transport'&>&~<&'hostname'&>&~<&'sequence&~number'&>&&&
3654 &~<&'message&~id'&>"
3655 .oindex "&%-MC%&"
3656 .cindex "SMTP" "passed connection"
3657 .cindex "SMTP" "multiple deliveries"
3658 .cindex "multiple SMTP deliveries"
3659 This option is not intended for use by external callers. It is used internally
3660 by Exim to invoke another instance of itself to deliver a waiting message using
3661 an existing SMTP connection, which is passed as the standard input. Details are
3662 given in chapter &<<CHAPSMTP>>&. This must be the final option, and the caller
3663 must be root or the Exim user in order to use it.
3665 .vitem &%-MCA%&
3666 .oindex "&%-MCA%&"
3667 This option is not intended for use by external callers. It is used internally
3668 by Exim in conjunction with the &%-MC%& option. It signifies that the
3669 connection to the remote host has been authenticated.
3671 .vitem &%-MCP%&
3672 .oindex "&%-MCP%&"
3673 This option is not intended for use by external callers. It is used internally
3674 by Exim in conjunction with the &%-MC%& option. It signifies that the server to
3675 which Exim is connected supports pipelining.
3677 .vitem &%-MCQ%&&~<&'process&~id'&>&~<&'pipe&~fd'&>
3678 .oindex "&%-MCQ%&"
3679 This option is not intended for use by external callers. It is used internally
3680 by Exim in conjunction with the &%-MC%& option when the original delivery was
3681 started by a queue runner. It passes on the process id of the queue runner,
3682 together with the file descriptor number of an open pipe. Closure of the pipe
3683 signals the final completion of the sequence of processes that are passing
3684 messages through the same SMTP connection.
3686 .vitem &%-MCS%&
3687 .oindex "&%-MCS%&"
3688 This option is not intended for use by external callers. It is used internally
3689 by Exim in conjunction with the &%-MC%& option, and passes on the fact that the
3690 SMTP SIZE option should be used on messages delivered down the existing
3691 connection.
3693 .vitem &%-MCT%&
3694 .oindex "&%-MCT%&"
3695 This option is not intended for use by external callers. It is used internally
3696 by Exim in conjunction with the &%-MC%& option, and passes on the fact that the
3697 host to which Exim is connected supports TLS encryption.
3699 .vitem &%-Mc%&&~<&'message&~id'&>&~<&'message&~id'&>&~...
3700 .oindex "&%-Mc%&"
3701 .cindex "hints database" "not overridden by &%-Mc%&"
3702 .cindex "delivery" "manually started &-- not forced"
3703 This option requests Exim to run a delivery attempt on each message in turn,
3704 but unlike the &%-M%& option, it does check for retry hints, and respects any
3705 that are found. This option is not very useful to external callers. It is
3706 provided mainly for internal use by Exim when it needs to re-invoke itself in
3707 order to regain root privilege for a delivery (see chapter &<<CHAPsecurity>>&).
3708 However, &%-Mc%& can be useful when testing, in order to run a delivery that
3709 respects retry times and other options such as &%hold_domains%& that are
3710 overridden when &%-M%& is used. Such a delivery does not count as a queue run.
3711 If you want to run a specific delivery as if in a queue run, you should use
3712 &%-q%& with a message id argument. A distinction between queue run deliveries
3713 and other deliveries is made in one or two places.
3715 .vitem &%-Mes%&&~<&'message&~id'&>&~<&'address'&>
3716 .oindex "&%-Mes%&"
3717 .cindex "message" "changing sender"
3718 .cindex "sender" "changing"
3719 This option requests Exim to change the sender address in the message to the
3720 given address, which must be a fully qualified address or &"<>"& (&"es"& for
3721 &"edit sender"&). There must be exactly two arguments. The first argument must
3722 be a message id, and the second one an email address. However, if the message
3723 is active (in the middle of a delivery attempt), its status is not altered.
3724 This option can be used only by an admin user.
3726 .vitem &%-Mf%&&~<&'message&~id'&>&~<&'message&~id'&>&~...
3727 .oindex "&%-Mf%&"
3728 .cindex "freezing messages"
3729 .cindex "message" "manually freezing"
3730 This option requests Exim to mark each listed message as &"frozen"&. This
3731 prevents any delivery attempts taking place until the message is &"thawed"&,
3732 either manually or as a result of the &%auto_thaw%& configuration option.
3733 However, if any of the messages are active (in the middle of a delivery
3734 attempt), their status is not altered. This option can be used only by an admin
3735 user.
3737 .vitem &%-Mg%&&~<&'message&~id'&>&~<&'message&~id'&>&~...
3738 .oindex "&%-Mg%&"
3739 .cindex "giving up on messages"
3740 .cindex "message" "abandoning delivery attempts"
3741 .cindex "delivery" "abandoning further attempts"
3742 This option requests Exim to give up trying to deliver the listed messages,
3743 including any that are frozen. However, if any of the messages are active,
3744 their status is not altered. For non-bounce messages, a delivery error message
3745 is sent to the sender, containing the text &"cancelled by administrator"&.
3746 Bounce messages are just discarded. This option can be used only by an admin
3747 user.
3749 .vitem &%-Mmad%&&~<&'message&~id'&>&~<&'message&~id'&>&~...
3750 .oindex "&%-Mmad%&"
3751 .cindex "delivery" "cancelling all"
3752 This option requests Exim to mark all the recipient addresses in the messages
3753 as already delivered (&"mad"& for &"mark all delivered"&). However, if any
3754 message is active (in the middle of a delivery attempt), its status is not
3755 altered. This option can be used only by an admin user.
3757 .vitem &%-Mmd%&&~<&'message&~id'&>&~<&'address'&>&~<&'address'&>&~...
3758 .oindex "&%-Mmd%&"
3759 .cindex "delivery" "cancelling by address"
3760 .cindex "recipient" "removing"
3761 .cindex "removing recipients"
3762 This option requests Exim to mark the given addresses as already delivered
3763 (&"md"& for &"mark delivered"&). The first argument must be a message id, and
3764 the remaining ones must be email addresses. These are matched to recipient
3765 addresses in the message in a case-sensitive manner. If the message is active
3766 (in the middle of a delivery attempt), its status is not altered. This option
3767 can be used only by an admin user.
3769 .vitem &%-Mrm%&&~<&'message&~id'&>&~<&'message&~id'&>&~...
3770 .oindex "&%-Mrm%&"
3771 .cindex "removing messages"
3772 .cindex "abandoning mail"
3773 .cindex "message" "manually discarding"
3774 This option requests Exim to remove the given messages from the queue. No
3775 bounce messages are sent; each message is simply forgotten. However, if any of
3776 the messages are active, their status is not altered. This option can be used
3777 only by an admin user or by the user who originally caused the message to be
3778 placed on the queue.
3780 .vitem &%-Mset%&&~<&'message&~id'&>
3781 .oindex "&%-Mset%&
3782 .cindex "testing" "string expansion"
3783 .cindex "expansion" "testing"
3784 This option is useful only in conjunction with &%-be%& (that is, when testing
3785 string expansions). Exim loads the given message from its spool before doing
3786 the test expansions, thus setting message-specific variables such as
3787 &$message_size$& and the header variables. The &$recipients$& variable is made
3788 available. This feature is provided to make it easier to test expansions that
3789 make use of these variables. However, this option can be used only by an admin
3790 user. See also &%-bem%&.
3792 .vitem &%-Mt%&&~<&'message&~id'&>&~<&'message&~id'&>&~...
3793 .oindex "&%-Mt%&"
3794 .cindex "thawing messages"
3795 .cindex "unfreezing messages"
3796 .cindex "frozen messages" "thawing"
3797 .cindex "message" "thawing frozen"
3798 This option requests Exim to &"thaw"& any of the listed messages that are
3799 &"frozen"&, so that delivery attempts can resume. However, if any of the
3800 messages are active, their status is not altered. This option can be used only
3801 by an admin user.
3803 .vitem &%-Mvb%&&~<&'message&~id'&>
3804 .oindex "&%-Mvb%&"
3805 .cindex "listing" "message body"
3806 .cindex "message" "listing body of"
3807 This option causes the contents of the message body (-D) spool file to be
3808 written to the standard output. This option can be used only by an admin user.
3810 .vitem &%-Mvc%&&~<&'message&~id'&>
3811 .oindex "&%-Mvc%&"
3812 .cindex "message" "listing in RFC 2822 format"
3813 .cindex "listing" "message in RFC 2822 format"
3814 This option causes a copy of the complete message (header lines plus body) to
3815 be written to the standard output in RFC 2822 format. This option can be used
3816 only by an admin user.
3818 .vitem &%-Mvh%&&~<&'message&~id'&>
3819 .oindex "&%-Mvh%&"
3820 .cindex "listing" "message headers"
3821 .cindex "header lines" "listing"
3822 .cindex "message" "listing header lines"
3823 This option causes the contents of the message headers (-H) spool file to be
3824 written to the standard output. This option can be used only by an admin user.
3826 .vitem &%-Mvl%&&~<&'message&~id'&>
3827 .oindex "&%-Mvl%&"
3828 .cindex "listing" "message log"
3829 .cindex "message" "listing message log"
3830 This option causes the contents of the message log spool file to be written to
3831 the standard output. This option can be used only by an admin user.
3833 .vitem &%-m%&
3834 .oindex "&%-m%&"
3835 This is apparently a synonym for &%-om%& that is accepted by Sendmail, so Exim
3836 treats it that way too.
3838 .vitem &%-N%&
3839 .oindex "&%-N%&"
3840 .cindex "debugging" "&%-N%& option"
3841 .cindex "debugging" "suppressing delivery"
3842 This is a debugging option that inhibits delivery of a message at the transport
3843 level. It implies &%-v%&. Exim goes through many of the motions of delivery &--
3844 it just doesn't actually transport the message, but instead behaves as if it
3845 had successfully done so. However, it does not make any updates to the retry
3846 database, and the log entries for deliveries are flagged with &"*>"& rather
3847 than &"=>"&.
3849 Because &%-N%& discards any message to which it applies, only root or the Exim
3850 user are allowed to use it with &%-bd%&, &%-q%&, &%-R%& or &%-M%&. In other
3851 words, an ordinary user can use it only when supplying an incoming message to
3852 which it will apply. Although transportation never fails when &%-N%& is set, an
3853 address may be deferred because of a configuration problem on a transport, or a
3854 routing problem. Once &%-N%& has been used for a delivery attempt, it sticks to
3855 the message, and applies to any subsequent delivery attempts that may happen
3856 for that message.
3858 .vitem &%-n%&
3859 .oindex "&%-n%&"
3860 .cindex "Sendmail compatibility" "&%-n%& option ignored"
3861 This option is interpreted by Sendmail to mean &"no aliasing"&. It is ignored
3862 by Exim.
3864 .vitem &%-O%&&~<&'data'&>
3865 .oindex "&%-O%&"
3866 This option is interpreted by Sendmail to mean &`set option`&. It is ignored by
3867 Exim.
3869 .vitem &%-oA%&&~<&'file&~name'&>
3870 .oindex "&%-oA%&"
3871 .cindex "Sendmail compatibility" "&%-oA%& option"
3872 This option is used by Sendmail in conjunction with &%-bi%& to specify an
3873 alternative alias file name. Exim handles &%-bi%& differently; see the
3874 description above.
3876 .vitem &%-oB%&&~<&'n'&>
3877 .oindex "&%-oB%&"
3878 .cindex "SMTP" "passed connection"
3879 .cindex "SMTP" "multiple deliveries"
3880 .cindex "multiple SMTP deliveries"
3881 This is a debugging option which limits the maximum number of messages that can
3882 be delivered down one SMTP connection, overriding the value set in any &(smtp)&
3883 transport. If <&'n'&> is omitted, the limit is set to 1.
3885 .vitem &%-odb%&
3886 .oindex "&%-odb%&"
3887 .cindex "background delivery"
3888 .cindex "delivery" "in the background"
3889 This option applies to all modes in which Exim accepts incoming messages,
3890 including the listening daemon. It requests &"background"& delivery of such
3891 messages, which means that the accepting process automatically starts a
3892 delivery process for each message received, but does not wait for the delivery
3893 processes to finish.
3895 When all the messages have been received, the reception process exits,
3896 leaving the delivery processes to finish in their own time. The standard output
3897 and error streams are closed at the start of each delivery process.
3898 This is the default action if none of the &%-od%& options are present.
3900 If one of the queueing options in the configuration file
3901 (&%queue_only%& or &%queue_only_file%&, for example) is in effect, &%-odb%&
3902 overrides it if &%queue_only_override%& is set true, which is the default
3903 setting. If &%queue_only_override%& is set false, &%-odb%& has no effect.
3905 .vitem &%-odf%&
3906 .oindex "&%-odf%&"
3907 .cindex "foreground delivery"
3908 .cindex "delivery" "in the foreground"
3909 This option requests &"foreground"& (synchronous) delivery when Exim has
3910 accepted a locally-generated message. (For the daemon it is exactly the same as
3911 &%-odb%&.) A delivery process is automatically started to deliver the message,
3912 and Exim waits for it to complete before proceeding.
3914 The original Exim reception process does not finish until the delivery
3915 process for the final message has ended. The standard error stream is left open
3916 during deliveries.
3918 However, like &%-odb%&, this option has no effect if &%queue_only_override%& is
3919 false and one of the queueing options in the configuration file is in effect.
3921 If there is a temporary delivery error during foreground delivery, the
3922 message is left on the queue for later delivery, and the original reception
3923 process exits. See chapter &<<CHAPnonqueueing>>& for a way of setting up a
3924 restricted configuration that never queues messages.
3927 .vitem &%-odi%&
3928 .oindex "&%-odi%&"
3929 This option is synonymous with &%-odf%&. It is provided for compatibility with
3930 Sendmail.
3932 .vitem &%-odq%&
3933 .oindex "&%-odq%&"
3934 .cindex "non-immediate delivery"
3935 .cindex "delivery" "suppressing immediate"
3936 .cindex "queueing incoming messages"
3937 This option applies to all modes in which Exim accepts incoming messages,
3938 including the listening daemon. It specifies that the accepting process should
3939 not automatically start a delivery process for each message received. Messages
3940 are placed on the queue, and remain there until a subsequent queue runner
3941 process encounters them. There are several configuration options (such as
3942 &%queue_only%&) that can be used to queue incoming messages under certain
3943 conditions. This option overrides all of them and also &%-odqs%&. It always
3944 forces queueing.
3946 .vitem &%-odqs%&
3947 .oindex "&%-odqs%&"
3948 .cindex "SMTP" "delaying delivery"
3949 This option is a hybrid between &%-odb%&/&%-odi%& and &%-odq%&.
3950 However, like &%-odb%& and &%-odi%&, this option has no effect if
3951 &%queue_only_override%& is false and one of the queueing options in the
3952 configuration file is in effect.
3954 When &%-odqs%& does operate, a delivery process is started for each incoming
3955 message, in the background by default, but in the foreground if &%-odi%& is
3956 also present. The recipient addresses are routed, and local deliveries are done
3957 in the normal way. However, if any SMTP deliveries are required, they are not
3958 done at this time, so the message remains on the queue until a subsequent queue
3959 runner process encounters it. Because routing was done, Exim knows which
3960 messages are waiting for which hosts, and so a number of messages for the same
3961 host can be sent in a single SMTP connection. The &%queue_smtp_domains%&
3962 configuration option has the same effect for specific domains. See also the
3963 &%-qq%& option.
3965 .vitem &%-oee%&
3966 .oindex "&%-oee%&"
3967 .cindex "error" "reporting"
3968 If an error is detected while a non-SMTP message is being received (for
3969 example, a malformed address), the error is reported to the sender in a mail
3970 message.
3972 .cindex "return code" "for &%-oee%&"
3973 Provided
3974 this error message is successfully sent, the Exim receiving process
3975 exits with a return code of zero. If not, the return code is 2 if the problem
3976 is that the original message has no recipients, or 1 any other error. This is
3977 the default &%-oe%&&'x'& option if Exim is called as &'rmail'&.
3979 .vitem &%-oem%&
3980 .oindex "&%-oem%&"
3981 .cindex "error" "reporting"
3982 .cindex "return code" "for &%-oem%&"
3983 This is the same as &%-oee%&, except that Exim always exits with a non-zero
3984 return code, whether or not the error message was successfully sent.
3985 This is the default &%-oe%&&'x'& option, unless Exim is called as &'rmail'&.
3987 .vitem &%-oep%&
3988 .oindex "&%-oep%&"
3989 .cindex "error" "reporting"
3990 If an error is detected while a non-SMTP message is being received, the
3991 error is reported by writing a message to the standard error file (stderr).
3992 .cindex "return code" "for &%-oep%&"
3993 The return code is 1 for all errors.
3995 .vitem &%-oeq%&
3996 .oindex "&%-oeq%&"
3997 .cindex "error" "reporting"