[exim.git] / doc / doc-docbook / spec.xfpt
1 . $Cambridge: exim/doc/doc-docbook/spec.xfpt,v 1.28 2008/01/17 12:56:12 nm4 Exp $
2 .
3 . /////////////////////////////////////////////////////////////////////////////
4 . This is the primary source of the Exim Manual. It is an xfpt document that is
5 . converted into DocBook XML for subsequent conversion into printing and online
6 . formats. The markup used herein is "standard" xfpt markup, with some extras.
7 . The markup is summarized in a file called Markup.txt.
8 .
9 . WARNING: When you use the .new macro, make sure it appears *before* any
10 . adjacent index items; otherwise you get an empty "paragraph" which causes
11 . unwanted vertical space.
12 . /////////////////////////////////////////////////////////////////////////////
14 .include stdflags
15 .include stdmacs
17 . /////////////////////////////////////////////////////////////////////////////
18 . This outputs the standard DocBook boilerplate.
19 . /////////////////////////////////////////////////////////////////////////////
21 .docbook
23 . /////////////////////////////////////////////////////////////////////////////
24 . These lines are processing instructions for the Simple DocBook Processor that
25 . Philip Hazel has developed as a less cumbersome way of making PostScript and
26 . PDFs than using xmlto and fop. They will be ignored by all other XML
27 . processors.
28 . /////////////////////////////////////////////////////////////////////////////
30 .literal xml
31 <?sdop
32 foot_right_recto="&chaptertitle; (&chapternumber;)"
33 foot_right_verso="&chaptertitle; (&chapternumber;)"
34 toc_chapter_blanks="yes,yes"
35 table_warn_overflow="overprint"
36 ?>
37 .literal off
39 . /////////////////////////////////////////////////////////////////////////////
40 . This generate the outermost <book> element that wraps then entire document.
41 . /////////////////////////////////////////////////////////////////////////////
43 .book
45 . /////////////////////////////////////////////////////////////////////////////
46 . These definitions set some parameters and save some typing. Remember that
47 . the <bookinfo> element must also be updated for each new edition.
48 . /////////////////////////////////////////////////////////////////////////////
50 .set previousversion "4.69"
51 .set version "4.70"
53 .set ACL "access control lists (ACLs)"
54 .set I "&nbsp;&nbsp;&nbsp;&nbsp;"
57 . /////////////////////////////////////////////////////////////////////////////
58 . Additional xfpt markup used by this document, over and above the default
59 . provided in the xfpt library.
60 . /////////////////////////////////////////////////////////////////////////////
62 . --- Override the &$ flag to automatically insert a $ with the variable name
64 .flag &$ $& "<varname>$" "</varname>"
66 . --- Short flags for daggers in option headings. They will always be inside
67 . --- an italic string, but we want the daggers to be roman.
69 .flag &!! "</emphasis>&dagger;<emphasis>"
70 .flag &!? "</emphasis>&Dagger;<emphasis>"
72 . --- A macro for an Exim option definition heading, generating a one-line
73 . --- table with four columns. For cases when the option name is given with
74 . --- a space, so that it can be split, a fifth argument is used for the
75 . --- index entry.
77 .macro option
78 .arg 5
79 .oindex "&%$5%&"
80 .endarg
81 .arg -5
82 .oindex "&%$1%&"
83 .endarg
84 .itable all 0 0 4 8* left 6* center 6* center 6* right
85 .row "&%$1%&" "Use: &'$2'&" "Type: &'$3'&" "Default: &'$4'&"
86 .endtable
87 .endmacro
89 . --- A macro for the common 2-column tables. The width of the first column
90 . --- is suitable for the many tables at the start of the main options chapter;
91 . --- the small number of other 2-column tables override it.
93 .macro table2 196pt 254pt
94 .itable none 0 0 2 $1 left $2 left
95 .endmacro
97 . --- A macro that generates .row, but puts &I; at the start of the first
98 . --- argument, thus indenting it. Assume a minimum of two arguments, and
99 . --- allow up to four arguments, which is as many as we'll ever need.
101 .macro irow
102 .arg 4
103 .row "&I;$1" "$2" "$3" "$4"
104 .endarg
105 .arg -4
106 .arg 3
107 .row "&I;$1" "$2" "$3"
108 .endarg
109 .arg -3
110 .row "&I;$1" "$2"
111 .endarg
112 .endarg
113 .endmacro
115 . --- Macros for option, variable, and concept index entries. For a "range"
116 . --- style of entry, use .scindex for the start and .ecindex for the end. The
117 . --- first argument of .scindex and the only argument of .ecindex must be the
118 . --- ID that ties them together.
120 .macro cindex
121 &<indexterm role="concept">&
122 &<primary>&$1&</primary>&
123 .arg 2
124 &<secondary>&$2&</secondary>&
125 .endarg
126 &</indexterm>&
127 .endmacro
129 .macro scindex
130 &<indexterm role="concept" id="$1" class="startofrange">&
131 &<primary>&$2&</primary>&
132 .arg 3
133 &<secondary>&$3&</secondary>&
134 .endarg
135 &</indexterm>&
136 .endmacro
138 .macro ecindex
139 &<indexterm role="concept" startref="$1" class="endofrange"/>&
140 .endmacro
142 .macro oindex
143 &<indexterm role="option">&
144 &<primary>&$1&</primary>&
145 .arg 2
146 &<secondary>&$2&</secondary>&
147 .endarg
148 &</indexterm>&
149 .endmacro
151 .macro vindex
152 &<indexterm role="variable">&
153 &<primary>&$1&</primary>&
154 .arg 2
155 &<secondary>&$2&</secondary>&
156 .endarg
157 &</indexterm>&
158 .endmacro
160 .macro index
161 .echo "** Don't use .index; use .cindex or .oindex or .vindex"
162 .endmacro
163 . ////////////////////////////////////////////////////////////////////////////
166 . ////////////////////////////////////////////////////////////////////////////
167 . The <bookinfo> element is removed from the XML before processing for Ascii
168 . output formats.
169 . ////////////////////////////////////////////////////////////////////////////
171 .literal xml
172 <bookinfo>
173 <title>Specification of the Exim Mail Transfer Agent</title>
174 <titleabbrev>The Exim MTA</titleabbrev>
175 <date>23 August 2007</date>
176 <author><firstname>Philip</firstname><surname>Hazel</surname></author>
177 <authorinitials>PH</authorinitials>
178 <affiliation><orgname>University of Cambridge Computing Service</orgname></affiliation>
179 <address>New Museums Site, Pembroke Street, Cambridge CB2 3QH, England</address>
180 <revhistory><revision>
181 <revnumber>4.68</revnumber>
182 <date>23 August 2007</date>
183 <authorinitials>PH</authorinitials>
184 </revision></revhistory>
185 <copyright><year>2007</year><holder>University of Cambridge</holder></copyright>
186 </bookinfo>
187 .literal off
190 . /////////////////////////////////////////////////////////////////////////////
191 . This chunk of literal XML implements index entries of the form "x, see y" and
192 . "x, see also y". However, the DocBook DTD doesn't allow <indexterm> entries
193 . at the top level, so we have to put the .chapter directive first.
194 . /////////////////////////////////////////////////////////////////////////////
196 .chapter "Introduction" "CHID1"
197 .literal xml
199 <indexterm role="variable">
200 <primary>$1, $2, etc.</primary>
201 <see><emphasis>numerical variables</emphasis></see>
202 </indexterm>
203 <indexterm role="concept">
204 <primary>address</primary>
205 <secondary>rewriting</secondary>
206 <see><emphasis>rewriting</emphasis></see>
207 </indexterm>
208 <indexterm role="concept">
209 <primary>Bounce Address Tag Validation</primary>
210 <see><emphasis>BATV</emphasis></see>
211 </indexterm>
212 <indexterm role="concept">
213 <primary>Client SMTP Authorization</primary>
214 <see><emphasis>CSA</emphasis></see>
215 </indexterm>
216 <indexterm role="concept">
217 <primary>CR character</primary>
218 <see><emphasis>carriage return</emphasis></see>
219 </indexterm>
220 <indexterm role="concept">
221 <primary>CRL</primary>
222 <see><emphasis>certificate revocation list</emphasis></see>
223 </indexterm>
224 <indexterm role="concept">
225 <primary>delivery</primary>
226 <secondary>failure report</secondary>
227 <see><emphasis>bounce message</emphasis></see>
228 </indexterm>
229 <indexterm role="concept">
230 <primary>dialup</primary>
231 <see><emphasis>intermittently connected hosts</emphasis></see>
232 </indexterm>
233 <indexterm role="concept">
234 <primary>exiscan</primary>
235 <see><emphasis>content scanning</emphasis></see>
236 </indexterm>
237 <indexterm role="concept">
238 <primary>failover</primary>
239 <see><emphasis>fallback</emphasis></see>
240 </indexterm>
241 <indexterm role="concept">
242 <primary>fallover</primary>
243 <see><emphasis>fallback</emphasis></see>
244 </indexterm>
245 <indexterm role="concept">
246 <primary>filter</primary>
247 <secondary>Sieve</secondary>
248 <see><emphasis>Sieve filter</emphasis></see>
249 </indexterm>
250 <indexterm role="concept">
251 <primary>ident</primary>
252 <see><emphasis>RFC 1413</emphasis></see>
253 </indexterm>
254 <indexterm role="concept">
255 <primary>LF character</primary>
256 <see><emphasis>linefeed</emphasis></see>
257 </indexterm>
258 <indexterm role="concept">
259 <primary>maximum</primary>
260 <seealso><emphasis>limit</emphasis></seealso>
261 </indexterm>
262 <indexterm role="concept">
263 <primary>monitor</primary>
264 <see><emphasis>Exim monitor</emphasis></see>
265 </indexterm>
266 <indexterm role="concept">
267 <primary>no_<emphasis>xxx</emphasis></primary>
268 <see>entry for xxx</see>
269 </indexterm>
270 <indexterm role="concept">
271 <primary>NUL</primary>
272 <see><emphasis>binary zero</emphasis></see>
273 </indexterm>
274 <indexterm role="concept">
275 <primary>passwd file</primary>
276 <see><emphasis>/etc/passwd</emphasis></see>
277 </indexterm>
278 <indexterm role="concept">
279 <primary>process id</primary>
280 <see><emphasis>pid</emphasis></see>
281 </indexterm>
282 <indexterm role="concept">
283 <primary>RBL</primary>
284 <see><emphasis>DNS list</emphasis></see>
285 </indexterm>
286 <indexterm role="concept">
287 <primary>redirection</primary>
288 <see><emphasis>address redirection</emphasis></see>
289 </indexterm>
290 <indexterm role="concept">
291 <primary>return path</primary>
292 <seealso><emphasis>envelope sender</emphasis></seealso>
293 </indexterm>
294 <indexterm role="concept">
295 <primary>scanning</primary>
296 <see><emphasis>content scanning</emphasis></see>
297 </indexterm>
298 <indexterm role="concept">
299 <primary>SSL</primary>
300 <see><emphasis>TLS</emphasis></see>
301 </indexterm>
302 <indexterm role="concept">
303 <primary>string</primary>
304 <secondary>expansion</secondary>
305 <see><emphasis>expansion</emphasis></see>
306 </indexterm>
307 <indexterm role="concept">
308 <primary>top bit</primary>
309 <see><emphasis>8-bit characters</emphasis></see>
310 </indexterm>
311 <indexterm role="concept">
312 <primary>variables</primary>
313 <see><emphasis>expansion, variables</emphasis></see>
314 </indexterm>
315 <indexterm role="concept">
316 <primary>zero, binary</primary>
317 <see><emphasis>binary zero</emphasis></see>
318 </indexterm>
320 .literal off
323 . /////////////////////////////////////////////////////////////////////////////
324 . This is the real start of the first chapter. See the comment above as to why
325 . we can't have the .chapter line here.
326 . chapter "Introduction"
327 . /////////////////////////////////////////////////////////////////////////////
329 Exim is a mail transfer agent (MTA) for hosts that are running Unix or
330 Unix-like operating systems. It was designed on the assumption that it would be
331 run on hosts that are permanently connected to the Internet. However, it can be
332 used on intermittently connected hosts with suitable configuration adjustments.
334 Configuration files currently exist for the following operating systems: AIX,
335 BSD/OS (aka BSDI), Darwin (Mac OS X), DGUX, Dragonfly, FreeBSD, GNU/Hurd,
336 GNU/Linux, HI-OSF (Hitachi), HI-UX, HP-UX, IRIX, MIPS RISCOS, NetBSD, OpenBSD,
337 OpenUNIX, QNX, SCO, SCO SVR4.2 (aka UNIX-SV), Solaris (aka SunOS5), SunOS4,
338 Tru64-Unix (formerly Digital UNIX, formerly DEC-OSF1), Ultrix, and Unixware.
339 Some of these operating systems are no longer current and cannot easily be
340 tested, so the configuration files may no longer work in practice.
342 There are also configuration files for compiling Exim in the Cygwin environment
343 that can be installed on systems running Windows. However, this document does
344 not contain any information about running Exim in the Cygwin environment.
346 The terms and conditions for the use and distribution of Exim are contained in
347 the file &_NOTICE_&. Exim is distributed under the terms of the GNU General
348 Public Licence, a copy of which may be found in the file &_LICENCE_&.
350 The use, supply or promotion of Exim for the purpose of sending bulk,
351 unsolicited electronic mail is incompatible with the basic aims of the program,
352 which revolve around the free provision of a service that enhances the quality
353 of personal communications. The author of Exim regards indiscriminate
354 mass-mailing as an antisocial, irresponsible abuse of the Internet.
356 Exim owes a great deal to Smail 3 and its author, Ron Karr. Without the
357 experience of running and working on the Smail 3 code, I could never have
358 contemplated starting to write a new MTA. Many of the ideas and user interfaces
359 were originally taken from Smail 3, though the actual code of Exim is entirely
360 new, and has developed far beyond the initial concept.
362 Many people, both in Cambridge and around the world, have contributed to the
363 development and the testing of Exim, and to porting it to various operating
364 systems. I am grateful to them all. The distribution now contains a file called
365 &_ACKNOWLEDGMENTS_&, in which I have started recording the names of
366 contributors.
369 .section "Exim documentation" "SECID1"
370 .new
371 .cindex "documentation"
372 This edition of the Exim specification applies to version &version; of Exim.
373 Substantive changes from the &previousversion; edition are marked in some
374 renditions of the document; this paragraph is so marked if the rendition is
375 capable of showing a change indicator.
376 .wen
378 This document is very much a reference manual; it is not a tutorial. The reader
379 is expected to have some familiarity with the SMTP mail transfer protocol and
380 with general Unix system administration. Although there are some discussions
381 and examples in places, the information is mostly organized in a way that makes
382 it easy to look up, rather than in a natural order for sequential reading.
383 Furthermore, the manual aims to cover every aspect of Exim in detail, including
384 a number of rarely-used, special-purpose features that are unlikely to be of
385 very wide interest.
387 .cindex "books about Exim"
388 An &"easier"& discussion of Exim which provides more in-depth explanatory,
389 introductory, and tutorial material can be found in a book entitled &'The Exim
390 SMTP Mail Server'& (second edition, 2007), published by UIT Cambridge
391 (&url(http://www.uit.co.uk/exim-book/)).
393 This book also contains a chapter that gives a general introduction to SMTP and
394 Internet mail. Inevitably, however, the book is unlikely to be fully up-to-date
395 with the latest release of Exim. (Note that the earlier book about Exim,
396 published by O'Reilly, covers Exim 3, and many things have changed in Exim 4.)
398 .cindex "Debian" "information sources"
399 If you are using a Debian distribution of Exim, you will find information about
400 Debian-specific features in the file
401 &_/usr/share/doc/exim4-base/README.Debian_&.
402 The command &(man update-exim.conf)& is another source of Debian-specific
403 information.
405 .cindex "&_doc/NewStuff_&"
406 .cindex "&_doc/ChangeLog_&"
407 .cindex "change log"
408 As the program develops, there may be features in newer versions that have not
409 yet made it into this document, which is updated only when the most significant
410 digit of the fractional part of the version number changes. Specifications of
411 new features that are not yet in this manual are placed in the file
412 &_doc/NewStuff_& in the Exim distribution.
414 Some features may be classified as &"experimental"&. These may change
415 incompatibly while they are developing, or even be withdrawn. For this reason,
416 they are not documented in this manual. Information about experimental features
417 can be found in the file &_doc/experimental.txt_&.
419 All changes to the program (whether new features, bug fixes, or other kinds of
420 change) are noted briefly in the file called &_doc/ChangeLog_&.
422 .cindex "&_doc/spec.txt_&"
423 This specification itself is available as an ASCII file in &_doc/spec.txt_& so
424 that it can easily be searched with a text editor. Other files in the &_doc_&
425 directory are:
427 .table2 100pt
428 .row &_OptionLists.txt_& "list of all options in alphabetical order"
429 .row &_dbm.discuss.txt_& "discussion about DBM libraries"
430 .row &_exim.8_& "a man page of Exim's command line options"
431 .row &_experimental.txt_& "documentation of experimental features"
432 .row &_filter.txt_& "specification of the filter language"
433 .row &_pcrepattern.txt_& "specification of PCRE regular expressions"
434 .row &_pcretest.txt_& "specification of the PCRE testing program"
435 .row &_Exim3.upgrade_& "upgrade notes from release 2 to release 3"
436 .row &_Exim4.upgrade_& "upgrade notes from release 3 to release 4"
437 .endtable
439 The main specification and the specification of the filtering language are also
440 available in other formats (HTML, PostScript, PDF, and Texinfo). Section
441 &<<SECTavail>>& below tells you how to get hold of these.
445 .section "FTP and web sites" "SECID2"
446 .cindex "web site"
447 .cindex "FTP site"
448 The primary site for Exim source distributions is currently the University of
449 Cambridge's FTP site, whose contents are described in &'Where to find the Exim
450 distribution'& below. In addition, there is a web site and an FTP site at
451 &%exim.org%&. These are now also hosted at the University of Cambridge. The
452 &%exim.org%& site was previously hosted for a number of years by Energis
453 Squared, formerly Planet Online Ltd, whose support I gratefully acknowledge.
455 .cindex "wiki"
456 .cindex "FAQ"
457 As well as Exim distribution tar files, the Exim web site contains a number of
458 differently formatted versions of the documentation. A recent addition to the
459 online information is the Exim wiki &new("(&url(http://wiki.exim.org))"),
460 which contains what used to be a separate FAQ, as well as various other
461 examples, tips, and know-how that have been contributed by Exim users.
463 .cindex Bugzilla
464 An Exim Bugzilla exists at &new("&url(http://bugs.exim.org)"). You can use
465 this to report bugs, and also to add items to the wish list. Please search
466 first to check that you are not duplicating a previous entry.
470 .section "Mailing lists" "SECID3"
471 .cindex "mailing lists" "for Exim users"
472 The following Exim mailing lists exist:
474 .table2 140pt
475 .row &'exim-users@exim.org'& "General discussion list"
476 .row &'exim-dev@exim.org'& "Discussion of bugs, enhancements, etc."
477 .row &'exim-announce@exim.org'& "Moderated, low volume announcements list"
478 .row &'exim-future@exim.org'& "Discussion of long-term development"
479 .endtable
481 You can subscribe to these lists, change your existing subscriptions, and view
482 or search the archives via the mailing lists link on the Exim home page.
483 .cindex "Debian" "mailing list for"
484 If you are using a Debian distribution of Exim, you may wish to subscribe to
485 the Debian-specific mailing list &'pkg-exim4-users@lists.alioth.debian.org'&
486 via this web page:
487 .display
488 &url(http://lists.alioth.debian.org/mailman/listinfo/pkg-exim4-users)
489 .endd
490 Please ask Debian-specific questions on this list and not on the general Exim
491 lists.
493 .section "Exim training" "SECID4"
494 .cindex "training courses"
495 Training courses in Cambridge (UK) used to be run annually by the author of
496 Exim, before he retired. At the time of writing, there are no plans to run
497 further Exim courses in Cambridge. However, if that changes, relevant
498 information will be posted at &url(http://www-tus.csx.cam.ac.uk/courses/exim/).
500 .section "Bug reports" "SECID5"
501 .cindex "bug reports"
502 .cindex "reporting bugs"
503 Reports of obvious bugs &new("can be emailed to &'bugs@exim.org'& or reported
504 via the Bugzilla (&url(http://bugs.exim.org)).") However, if you are unsure
505 whether some behaviour is a bug or not, the best thing to do is to post a
506 message to the &'exim-dev'& mailing list and have it discussed.
510 .section "Where to find the Exim distribution" "SECTavail"
511 .cindex "FTP site"
512 .cindex "distribution" "ftp site"
513 The master ftp site for the Exim distribution is
514 .display
515 &*ftp://ftp.csx.cam.ac.uk/pub/software/email/exim*&
516 .endd
517 This is mirrored by
518 .display
519 &*ftp://ftp.exim.org/pub/exim*&
520 .endd
521 The file references that follow are relative to the &_exim_& directories at
522 these sites. There are now quite a number of independent mirror sites around
523 the world. Those that I know about are listed in the file called &_Mirrors_&.
525 Within the &_exim_& directory there are subdirectories called &_exim3_& (for
526 previous Exim 3 distributions), &_exim4_& (for the latest Exim 4
527 distributions), and &_Testing_& for testing versions. In the &_exim4_&
528 subdirectory, the current release can always be found in files called
529 .display
530 &_exim-n.nn.tar.gz_&
531 &_exim-n.nn.tar.bz2_&
532 .endd
533 where &'n.nn'& is the highest such version number in the directory. The two
534 files contain identical data; the only difference is the type of compression.
535 The &_.bz2_& file is usually a lot smaller than the &_.gz_& file.
537 .cindex "distribution" "signing details"
538 .cindex "distribution" "public key"
539 .cindex "public key for signed distribution"
540 The distributions are currently signed with Nigel Metheringham's GPG key. The
541 corresponding public key is available from a number of keyservers, and there is
542 also a copy in the file &_nigel-pubkey.asc_&. The signatures for the tar bundles are
543 in:
544 .display
545 &_exim-n.nn.tar.gz.asc_&
546 &_exim-n.nn.tar.bz2.asc_&
547 .endd
548 For each released version, the log of changes is made separately available in a
549 separate file in the directory &_ChangeLogs_& so that it is possible to
550 find out what has changed without having to download the entire distribution.
552 .cindex "documentation" "available formats"
553 The main distribution contains ASCII versions of this specification and other
554 documentation; other formats of the documents are available in separate files
555 inside the &_exim4_& directory of the FTP site:
556 .display
557 &_exim-html-n.nn.tar.gz_&
558 &_exim-pdf-n.nn.tar.gz_&
559 &_exim-postscript-n.nn.tar.gz_&
560 &_exim-texinfo-n.nn.tar.gz_&
561 .endd
562 These tar files contain only the &_doc_& directory, not the complete
563 distribution, and are also available in &_.bz2_& as well as &_.gz_& forms.
566 .section "Limitations" "SECID6"
567 .ilist
568 .cindex "limitations of Exim"
569 .cindex "bang paths" "not handled by Exim"
570 Exim is designed for use as an Internet MTA, and therefore handles addresses in
571 RFC 2822 domain format only. It cannot handle UUCP &"bang paths"&, though
572 simple two-component bang paths can be converted by a straightforward rewriting
573 configuration. This restriction does not prevent Exim from being interfaced to
574 UUCP as a transport mechanism, provided that domain addresses are used.
575 .next
576 .cindex "domainless addresses"
577 .cindex "address" "without domain"
578 Exim insists that every address it handles has a domain attached. For incoming
579 local messages, domainless addresses are automatically qualified with a
580 configured domain value. Configuration options specify from which remote
581 systems unqualified addresses are acceptable. These are then qualified on
582 arrival.
583 .next
584 .cindex "transport" "external"
585 .cindex "external transports"
586 The only external transport mechanisms that are currently implemented are SMTP
587 and LMTP over a TCP/IP network (including support for IPv6). However, a pipe
588 transport is available, and there are facilities for writing messages to files
589 and pipes, optionally in &'batched SMTP'& format; these facilities can be used
590 to send messages to other transport mechanisms such as UUCP, provided they can
591 handle domain-style addresses. Batched SMTP input is also catered for.
592 .next
593 Exim is not designed for storing mail for dial-in hosts. When the volumes of
594 such mail are large, it is better to get the messages &"delivered"& into files
595 (that is, off Exim's queue) and subsequently passed on to the dial-in hosts by
596 other means.
597 .next
598 Although Exim does have basic facilities for scanning incoming messages, these
599 are not comprehensive enough to do full virus or spam scanning. Such operations
600 are best carried out using additional specialized software packages. If you
601 compile Exim with the content-scanning extension, straightforward interfaces to
602 a number of common scanners are provided.
603 .endlist
606 .section "Run time configuration" "SECID7"
607 Exim's run time configuration is held in a single text file that is divided
608 into a number of sections. The entries in this file consist of keywords and
609 values, in the style of Smail 3 configuration files. A default configuration
610 file which is suitable for simple online installations is provided in the
611 distribution, and is described in chapter &<<CHAPdefconfil>>& below.
614 .section "Calling interface" "SECID8"
615 .cindex "Sendmail compatibility" "command line interface"
616 Like many MTAs, Exim has adopted the Sendmail command line interface so that it
617 can be a straight replacement for &_/usr/lib/sendmail_& or
618 &_/usr/sbin/sendmail_& when sending mail, but you do not need to know anything
619 about Sendmail in order to run Exim. For actions other than sending messages,
620 Sendmail-compatible options also exist, but those that produce output (for
621 example, &%-bp%&, which lists the messages on the queue) do so in Exim's own
622 format. There are also some additional options that are compatible with Smail
623 3, and some further options that are new to Exim. Chapter &<<CHAPcommandline>>&
624 documents all Exim's command line options. This information is automatically
625 made into the man page that forms part of the Exim distribution.
627 Control of messages on the queue can be done via certain privileged command
628 line options. There is also an optional monitor program called &'eximon'&,
629 which displays current information in an X window, and which contains a menu
630 interface to Exim's command line administration options.
634 .section "Terminology" "SECID9"
635 .cindex "terminology definitions"
636 .cindex "body of message" "definition of"
637 The &'body'& of a message is the actual data that the sender wants to transmit.
638 It is the last part of a message, and is separated from the &'header'& (see
639 below) by a blank line.
641 .cindex "bounce message" "definition of"
642 When a message cannot be delivered, it is normally returned to the sender in a
643 delivery failure message or a &"non-delivery report"& (NDR). The term
644 &'bounce'& is commonly used for this action, and the error reports are often
645 called &'bounce messages'&. This is a convenient shorthand for &"delivery
646 failure error report"&. Such messages have an empty sender address in the
647 message's &'envelope'& (see below) to ensure that they cannot themselves give
648 rise to further bounce messages.
650 The term &'default'& appears frequently in this manual. It is used to qualify a
651 value which is used in the absence of any setting in the configuration. It may
652 also qualify an action which is taken unless a configuration setting specifies
653 otherwise.
655 The term &'defer'& is used when the delivery of a message to a specific
656 destination cannot immediately take place for some reason (a remote host may be
657 down, or a user's local mailbox may be full). Such deliveries are &'deferred'&
658 until a later time.
660 The word &'domain'& is sometimes used to mean all but the first component of a
661 host's name. It is &'not'& used in that sense here, where it normally refers to
662 the part of an email address following the @ sign.
664 .cindex "envelope, definition of"
665 .cindex "sender" "definition of"
666 A message in transit has an associated &'envelope'&, as well as a header and a
667 body. The envelope contains a sender address (to which bounce messages should
668 be delivered), and any number of recipient addresses. References to the
669 sender or the recipients of a message usually mean the addresses in the
670 envelope. An MTA uses these addresses for delivery, and for returning bounce
671 messages, not the addresses that appear in the header lines.
673 .cindex "message" "header, definition of"
674 .cindex "header section" "definition of"
675 The &'header'& of a message is the first part of a message's text, consisting
676 of a number of lines, each of which has a name such as &'From:'&, &'To:'&,
677 &'Subject:'&, etc. Long header lines can be split over several text lines by
678 indenting the continuations. The header is separated from the body by a blank
679 line.
681 .cindex "local part" "definition of"
682 .cindex "domain" "definition of"
683 The term &'local part'&, which is taken from RFC 2822, is used to refer to that
684 part of an email address that precedes the @ sign. The part that follows the
685 @ sign is called the &'domain'& or &'mail domain'&.
687 .cindex "local delivery" "definition of"
688 .cindex "remote delivery, definition of"
689 The terms &'local delivery'& and &'remote delivery'& are used to distinguish
690 delivery to a file or a pipe on the local host from delivery by SMTP over
691 TCP/IP to another host. As far as Exim is concerned, all hosts other than the
692 host it is running on are &'remote'&.
694 .cindex "return path" "definition of"
695 &'Return path'& is another name that is used for the sender address in a
696 message's envelope.
698 .cindex "queue" "definition of"
699 The term &'queue'& is used to refer to the set of messages awaiting delivery,
700 because this term is in widespread use in the context of MTAs. However, in
701 Exim's case the reality is more like a pool than a queue, because there is
702 normally no ordering of waiting messages.
704 .cindex "queue runner" "definition of"
705 The term &'queue runner'& is used to describe a process that scans the queue
706 and attempts to deliver those messages whose retry times have come. This term
707 is used by other MTAs, and also relates to the command &%runq%&, but in Exim
708 the waiting messages are normally processed in an unpredictable order.
710 .cindex "spool directory" "definition of"
711 The term &'spool directory'& is used for a directory in which Exim keeps the
712 messages on its queue &-- that is, those that it is in the process of
713 delivering. This should not be confused with the directory in which local
714 mailboxes are stored, which is called a &"spool directory"& by some people. In
715 the Exim documentation, &"spool"& is always used in the first sense.
722 . ////////////////////////////////////////////////////////////////////////////
723 . ////////////////////////////////////////////////////////////////////////////
725 .chapter "Incorporated code" "CHID2"
726 .cindex "incorporated code"
727 .cindex "regular expressions" "library"
728 .cindex "PCRE"
729 A number of pieces of external code are included in the Exim distribution.
731 .ilist
732 Regular expressions are supported in the main Exim program and in the
733 Exim monitor using the freely-distributable PCRE library, copyright
734 &copy; University of Cambridge. The source to a cut down version of PCRE
735 used to be distributed in the directory &_src/pcre_&. However, this is
736 no longer the case and you will need to use a system PCRE library or
737 obtain and install the full version of the library from
738 &url(ftp://ftp.csx.cam.ac.uk/pub/software/programming/pcre).
739 .next
740 .cindex "cdb" "acknowledgment"
741 Support for the cdb (Constant DataBase) lookup method is provided by code
742 contributed by Nigel Metheringham of (at the time he contributed it) Planet
743 Online Ltd. The implementation is completely contained within the code of Exim.
744 It does not link against an external cdb library. The code contains the
745 following statements:
747 .blockquote
748 Copyright &copy; 1998 Nigel Metheringham, Planet Online Ltd
750 This program is free software; you can redistribute it and/or modify it under
751 the terms of the GNU General Public License as published by the Free Software
752 Foundation; either version 2 of the License, or (at your option) any later
753 version.
754 This code implements Dan Bernstein's Constant DataBase (cdb) spec. Information,
755 the spec and sample code for cdb can be obtained from
756 &url(http://www.pobox.com/~djb/cdb.html). This implementation borrows
757 some code from Dan Bernstein's implementation (which has no license
758 restrictions applied to it).
759 .endblockquote
760 .next
761 .cindex "SPA authentication"
762 .cindex "Samba project"
763 .cindex "Microsoft Secure Password Authentication"
764 Client support for Microsoft's &'Secure Password Authentication'& is provided
765 by code contributed by Marc Prud'hommeaux. Server support was contributed by
766 Tom Kistner. This includes code taken from the Samba project, which is released
767 under the Gnu GPL.
768 .next
769 .cindex "Cyrus"
770 .cindex "&'pwcheck'& daemon"
771 .cindex "&'pwauthd'& daemon"
772 Support for calling the Cyrus &'pwcheck'& and &'saslauthd'& daemons is provided
773 by code taken from the Cyrus-SASL library and adapted by Alexander S.
774 Sabourenkov. The permission notice appears below, in accordance with the
775 conditions expressed therein.
777 .blockquote
778 Copyright &copy; 2001 Carnegie Mellon University. All rights reserved.
780 Redistribution and use in source and binary forms, with or without
781 modification, are permitted provided that the following conditions
782 are met:
784 .olist
785 Redistributions of source code must retain the above copyright
786 notice, this list of conditions and the following disclaimer.
787 .next
788 Redistributions in binary form must reproduce the above copyright
789 notice, this list of conditions and the following disclaimer in
790 the documentation and/or other materials provided with the
791 distribution.
792 .next
793 The name &"Carnegie Mellon University"& must not be used to
794 endorse or promote products derived from this software without
795 prior written permission. For permission or any other legal
796 details, please contact
797 .display
798 Office of Technology Transfer
799 Carnegie Mellon University
800 5000 Forbes Avenue
801 Pittsburgh, PA 15213-3890
802 (412) 268-4387, fax: (412) 268-7395
803 tech-transfer@andrew.cmu.edu
804 .endd
805 .next
806 Redistributions of any form whatsoever must retain the following
807 acknowledgment:
809 &"This product includes software developed by Computing Services
810 at Carnegie Mellon University (&url(http://www.cmu.edu/computing/)."&
819 .endlist
820 .endblockquote
822 .next
823 .cindex "Exim monitor" "acknowledgment"
824 .cindex "X-windows"
825 .cindex "Athena"
826 The Exim Monitor program, which is an X-Window application, includes
827 modified versions of the Athena StripChart and TextPop widgets.
828 This code is copyright by DEC and MIT, and their permission notice appears
829 below, in accordance with the conditions expressed therein.
831 .blockquote
832 Copyright 1987, 1988 by Digital Equipment Corporation, Maynard, Massachusetts,
833 and the Massachusetts Institute of Technology, Cambridge, Massachusetts.
835 All Rights Reserved
837 Permission to use, copy, modify, and distribute this software and its
838 documentation for any purpose and without fee is hereby granted,
839 provided that the above copyright notice appear in all copies and that
840 both that copyright notice and this permission notice appear in
841 supporting documentation, and that the names of Digital or MIT not be
842 used in advertising or publicity pertaining to distribution of the
843 software without specific, written prior permission.
852 .endblockquote
854 .next
855 Many people have contributed code fragments, some large, some small, that were
856 not covered by any specific licence requirements. It is assumed that the
857 contributors are happy to see their code incorporated into Exim under the GPL.
858 .endlist
864 . ////////////////////////////////////////////////////////////////////////////
865 . ////////////////////////////////////////////////////////////////////////////
867 .chapter "How Exim receives and delivers mail" "CHID11" &&&
868 "Receiving and delivering mail"
871 .section "Overall philosophy" "SECID10"
872 .cindex "design philosophy"
873 Exim is designed to work efficiently on systems that are permanently connected
874 to the Internet and are handling a general mix of mail. In such circumstances,
875 most messages can be delivered immediately. Consequently, Exim does not
876 maintain independent queues of messages for specific domains or hosts, though
877 it does try to send several messages in a single SMTP connection after a host
878 has been down, and it also maintains per-host retry information.
881 .section "Policy control" "SECID11"
882 .cindex "policy control" "overview"
883 Policy controls are now an important feature of MTAs that are connected to the
884 Internet. Perhaps their most important job is to stop MTAs being abused as
885 &"open relays"& by misguided individuals who send out vast amounts of
886 unsolicited junk, and want to disguise its source. Exim provides flexible
887 facilities for specifying policy controls on incoming mail:
889 .ilist
890 .cindex "&ACL;" "introduction"
891 Exim 4 (unlike previous versions of Exim) implements policy controls on
892 incoming mail by means of &'Access Control Lists'& (ACLs). Each list is a
893 series of statements that may either grant or deny access. ACLs can be used at
894 several places in the SMTP dialogue while receiving a message from a remote
895 host. However, the most common places are after each RCPT command, and at the
896 very end of the message. The sysadmin can specify conditions for accepting or
897 rejecting individual recipients or the entire message, respectively, at these
898 two points (see chapter &<<CHAPACL>>&). Denial of access results in an SMTP
899 error code.
900 .next
901 An ACL is also available for locally generated, non-SMTP messages. In this
902 case, the only available actions are to accept or deny the entire message.
903 .next
904 When Exim is compiled with the content-scanning extension, facilities are
905 provided in the ACL mechanism for passing the message to external virus and/or
906 spam scanning software. The result of such a scan is passed back to the ACL,
907 which can then use it to decide what to do with the message.
908 .next
909 When a message has been received, either from a remote host or from the local
910 host, but before the final acknowledgment has been sent, a locally supplied C
911 function called &[local_scan()]& can be run to inspect the message and decide
912 whether to accept it or not (see chapter &<<CHAPlocalscan>>&). If the message
913 is accepted, the list of recipients can be modified by the function.
914 .next
915 Using the &[local_scan()]& mechanism is another way of calling external scanner
916 software. The &%SA-Exim%& add-on package works this way. It does not require
917 Exim to be compiled with the content-scanning extension.
918 .next
919 After a message has been accepted, a further checking mechanism is available in
920 the form of the &'system filter'& (see chapter &<<CHAPsystemfilter>>&). This
921 runs at the start of every delivery process.
922 .endlist
926 .section "User filters" "SECID12"
927 .cindex "filter" "introduction"
928 .cindex "Sieve filter"
929 In a conventional Exim configuration, users are able to run private filters by
930 setting up appropriate &_.forward_& files in their home directories. See
931 chapter &<<CHAPredirect>>& (about the &(redirect)& router) for the
932 configuration needed to support this, and the separate document entitled
933 &'Exim's interfaces to mail filtering'& for user details. Two different kinds
934 of filtering are available:
936 .ilist
937 Sieve filters are written in the standard filtering language that is defined
938 by RFC 3028.
939 .next
940 Exim filters are written in a syntax that is unique to Exim, but which is more
941 powerful than Sieve, which it pre-dates.
942 .endlist
944 User filters are run as part of the routing process, described below.
948 .section "Message identification" "SECTmessiden"
949 .cindex "message ids" "details of format"
950 .cindex "format" "of message id"
951 .cindex "id of message"
952 .cindex "base62"
953 .cindex "base36"
954 .cindex "Darwin"
955 .cindex "Cygwin"
956 Every message handled by Exim is given a &'message id'& which is sixteen
957 characters long. It is divided into three parts, separated by hyphens, for
958 example &`16VDhn-0001bo-D3`&. Each part is a sequence of letters and digits,
959 normally encoding numbers in base 62. However, in the Darwin operating
960 system (Mac OS X) and when Exim is compiled to run under Cygwin, base 36
961 (avoiding the use of lower case letters) is used instead, because the message
962 id is used to construct file names, and the names of files in those systems are
963 not always case-sensitive.
965 .cindex "pid (process id)" "re-use of"
966 The detail of the contents of the message id have changed as Exim has evolved.
967 Earlier versions relied on the operating system not re-using a process id (pid)
968 within one second. On modern operating systems, this assumption can no longer
969 be made, so the algorithm had to be changed. To retain backward compatibility,
970 the format of the message id was retained, which is why the following rules are
971 somewhat eccentric:
973 .ilist
974 The first six characters of the message id are the time at which the message
975 started to be received, to a granularity of one second. That is, this field
976 contains the number of seconds since the start of the epoch (the normal Unix
977 way of representing the date and time of day).
978 .next
979 After the first hyphen, the next six characters are the id of the process that
980 received the message.
981 .next
982 There are two different possibilities for the final two characters:
983 .olist
984 .oindex "&%localhost_number%&"
985 If &%localhost_number%& is not set, this value is the fractional part of the
986 time of reception, normally in units of 1/2000 of a second, but for systems
987 that must use base 36 instead of base 62 (because of case-insensitive file
988 systems), the units are 1/1000 of a second.
989 .next
990 If &%localhost_number%& is set, it is multiplied by 200 (100) and added to
991 the fractional part of the time, which in this case is in units of 1/200
992 (1/100) of a second.
993 .endlist
994 .endlist
996 After a message has been received, Exim waits for the clock to tick at the
997 appropriate resolution before proceeding, so that if another message is
998 received by the same process, or by another process with the same (re-used)
999 pid, it is guaranteed that the time will be different. In most cases, the clock
1000 will already have ticked while the message was being received.
1003 .section "Receiving mail" "SECID13"
1004 .cindex "receiving mail"
1005 .cindex "message" "reception"
1006 The only way Exim can receive mail from another host is using SMTP over
1007 TCP/IP, in which case the sender and recipient addresses are transferred using
1008 SMTP commands. However, from a locally running process (such as a user's MUA),
1009 there are several possibilities:
1011 .ilist
1012 If the process runs Exim with the &%-bm%& option, the message is read
1013 non-interactively (usually via a pipe), with the recipients taken from the
1014 command line, or from the body of the message if &%-t%& is also used.
1015 .next
1016 If the process runs Exim with the &%-bS%& option, the message is also read
1017 non-interactively, but in this case the recipients are listed at the start of
1018 the message in a series of SMTP RCPT commands, terminated by a DATA
1019 command. This is so-called &"batch SMTP"& format,
1020 but it isn't really SMTP. The SMTP commands are just another way of passing
1021 envelope addresses in a non-interactive submission.
1022 .next
1023 If the process runs Exim with the &%-bs%& option, the message is read
1024 interactively, using the SMTP protocol. A two-way pipe is normally used for
1025 passing data between the local process and the Exim process.
1026 This is &"real"& SMTP and is handled in the same way as SMTP over TCP/IP. For
1027 example, the ACLs for SMTP commands are used for this form of submission.
1028 .next
1029 A local process may also make a TCP/IP call to the host's loopback address
1030 ( or any other of its IP addresses. When receiving messages, Exim
1031 does not treat the loopback address specially. It treats all such connections
1032 in the same way as connections from other hosts.
1033 .endlist
1036 .cindex "message sender, constructed by Exim"
1037 .cindex "sender" "constructed by Exim"
1038 In the three cases that do not involve TCP/IP, the sender address is
1039 constructed from the login name of the user that called Exim and a default
1040 qualification domain (which can be set by the &%qualify_domain%& configuration
1041 option). For local or batch SMTP, a sender address that is passed using the
1042 SMTP MAIL command is ignored. However, the system administrator may allow
1043 certain users (&"trusted users"&) to specify a different sender address
1044 unconditionally, or all users to specify certain forms of different sender
1045 address. The &%-f%& option or the SMTP MAIL command is used to specify these
1046 different addresses. See section &<<SECTtrustedadmin>>& for details of trusted
1047 users, and the &%untrusted_set_sender%& option for a way of allowing untrusted
1048 users to change sender addresses.
1050 Messages received by either of the non-interactive mechanisms are subject to
1051 checking by the non-SMTP ACL, if one is defined. Messages received using SMTP
1052 (either over TCP/IP, or interacting with a local process) can be checked by a
1053 number of ACLs that operate at different times during the SMTP session. Either
1054 individual recipients, or the entire message, can be rejected if local policy
1055 requirements are not met. The &[local_scan()]& function (see chapter
1056 &<<CHAPlocalscan>>&) is run for all incoming messages.
1058 Exim can be configured not to start a delivery process when a message is
1059 received; this can be unconditional, or depend on the number of incoming SMTP
1060 connections or the system load. In these situations, new messages wait on the
1061 queue until a queue runner process picks them up. However, in standard
1062 configurations under normal conditions, delivery is started as soon as a
1063 message is received.
1069 .section "Handling an incoming message" "SECID14"
1070 .cindex "spool directory" "files that hold a message"
1071 .cindex "file" "how a message is held"
1072 When Exim accepts a message, it writes two files in its spool directory. The
1073 first contains the envelope information, the current status of the message, and
1074 the header lines, and the second contains the body of the message. The names of
1075 the two spool files consist of the message id, followed by &`-H`& for the
1076 file containing the envelope and header, and &`-D`& for the data file.
1078 .cindex "spool directory" "&_input_& sub-directory"
1079 By default all these message files are held in a single directory called
1080 &_input_& inside the general Exim spool directory. Some operating systems do
1081 not perform very well if the number of files in a directory gets large; to
1082 improve performance in such cases, the &%split_spool_directory%& option can be
1083 used. This causes Exim to split up the input files into 62 sub-directories
1084 whose names are single letters or digits. When this is done, the queue is
1085 processed one sub-directory at a time instead of all at once, which can improve
1086 overall performance even when there are not enough files in each directory to
1087 affect file system performance.
1089 The envelope information consists of the address of the message's sender and
1090 the addresses of the recipients. This information is entirely separate from
1091 any addresses contained in the header lines. The status of the message includes
1092 a list of recipients who have already received the message. The format of the
1093 first spool file is described in chapter &<<CHAPspool>>&.
1095 .cindex "rewriting" "addresses"
1096 Address rewriting that is specified in the rewrite section of the configuration
1097 (see chapter &<<CHAPrewrite>>&) is done once and for all on incoming addresses,
1098 both in the header lines and the envelope, at the time the message is accepted.
1099 If during the course of delivery additional addresses are generated (for
1100 example, via aliasing), these new addresses are rewritten as soon as they are
1101 generated. At the time a message is actually delivered (transported) further
1102 rewriting can take place; because this is a transport option, it can be
1103 different for different forms of delivery. It is also possible to specify the
1104 addition or removal of certain header lines at the time the message is
1105 delivered (see chapters &<<CHAProutergeneric>>& and
1106 &<<CHAPtransportgeneric>>&).
1110 .section "Life of a message" "SECID15"
1111 .cindex "message" "life of"
1112 .cindex "message" "frozen"
1113 A message remains in the spool directory until it is completely delivered to
1114 its recipients or to an error address, or until it is deleted by an
1115 administrator or by the user who originally created it. In cases when delivery
1116 cannot proceed &-- for example, when a message can neither be delivered to its
1117 recipients nor returned to its sender, the message is marked &"frozen"& on the
1118 spool, and no more deliveries are attempted.
1120 .cindex "frozen messages" "thawing"
1121 .cindex "message" "thawing frozen"
1122 An administrator can &"thaw"& such messages when the problem has been
1123 corrected, and can also freeze individual messages by hand if necessary. In
1124 addition, an administrator can force a delivery error, causing a bounce message
1125 to be sent.
1127 .oindex "&%timeout_frozen_after%&"
1128 .oindex "&%ignore_bounce_errors_after%&"
1129 There are options called &%ignore_bounce_errors_after%& and
1130 &%timeout_frozen_after%&, which discard frozen messages after a certain time.
1131 The first applies only to frozen bounces, the second to any frozen messages.
1133 .cindex "message" "log file for"
1134 .cindex "log" "file for each message"
1135 While Exim is working on a message, it writes information about each delivery
1136 attempt to its main log file. This includes successful, unsuccessful, and
1137 delayed deliveries for each recipient (see chapter &<<CHAPlog>>&). The log
1138 lines are also written to a separate &'message log'& file for each message.
1139 These logs are solely for the benefit of the administrator, and are normally
1140 deleted along with the spool files when processing of a message is complete.
1141 The use of individual message logs can be disabled by setting
1142 &%no_message_logs%&; this might give an improvement in performance on very busy
1143 systems.
1145 .cindex "journal file"
1146 .cindex "file" "journal"
1147 All the information Exim itself needs to set up a delivery is kept in the first
1148 spool file, along with the header lines. When a successful delivery occurs, the
1149 address is immediately written at the end of a journal file, whose name is the
1150 message id followed by &`-J`&. At the end of a delivery run, if there are some
1151 addresses left to be tried again later, the first spool file (the &`-H`& file)
1152 is updated to indicate which these are, and the journal file is then deleted.
1153 Updating the spool file is done by writing a new file and renaming it, to
1154 minimize the possibility of data loss.
1156 Should the system or the program crash after a successful delivery but before
1157 the spool file has been updated, the journal is left lying around. The next
1158 time Exim attempts to deliver the message, it reads the journal file and
1159 updates the spool file before proceeding. This minimizes the chances of double
1160 deliveries caused by crashes.
1164 .section "Processing an address for delivery" "SECTprocaddress"
1165 .cindex "drivers" "definition of"
1166 .cindex "router" "definition of"
1167 .cindex "transport" "definition of"
1168 The main delivery processing elements of Exim are called &'routers'& and
1169 &'transports'&, and collectively these are known as &'drivers'&. Code for a
1170 number of them is provided in the source distribution, and compile-time options
1171 specify which ones are included in the binary. Run time options specify which
1172 ones are actually used for delivering messages.
1174 .cindex "drivers" "instance definition"
1175 Each driver that is specified in the run time configuration is an &'instance'&
1176 of that particular driver type. Multiple instances are allowed; for example,
1177 you can set up several different &(smtp)& transports, each with different
1178 option values that might specify different ports or different timeouts. Each
1179 instance has its own identifying name. In what follows we will normally use the
1180 instance name when discussing one particular instance (that is, one specific
1181 configuration of the driver), and the generic driver name when discussing
1182 the driver's features in general.
1184 A &'router'& is a driver that operates on an address, either determining how
1185 its delivery should happen, by assigning it to a specific transport, or
1186 converting the address into one or more new addresses (for example, via an
1187 alias file). A router may also explicitly choose to fail an address, causing it
1188 to be bounced.
1190 A &'transport'& is a driver that transmits a copy of the message from Exim's
1191 spool to some destination. There are two kinds of transport: for a &'local'&
1192 transport, the destination is a file or a pipe on the local host, whereas for a
1193 &'remote'& transport the destination is some other host. A message is passed
1194 to a specific transport as a result of successful routing. If a message has
1195 several recipients, it may be passed to a number of different transports.
1197 .cindex "preconditions" "definition of"
1198 An address is processed by passing it to each configured router instance in
1199 turn, subject to certain preconditions, until a router accepts the address or
1200 specifies that it should be bounced. We will describe this process in more
1201 detail shortly. First, as a simple example, we consider how each recipient
1202 address in a message is processed in a small configuration of three routers.
1204 To make this a more concrete example, it is described in terms of some actual
1205 routers, but remember, this is only an example. You can configure Exim's
1206 routers in many different ways, and there may be any number of routers in a
1207 configuration.
1209 The first router that is specified in a configuration is often one that handles
1210 addresses in domains that are not recognized specially by the local host. These
1211 are typically addresses for arbitrary domains on the Internet. A precondition
1212 is set up which looks for the special domains known to the host (for example,
1213 its own domain name), and the router is run for addresses that do &'not'&
1214 match. Typically, this is a router that looks up domains in the DNS in order to
1215 find the hosts to which this address routes. If it succeeds, the address is
1216 assigned to a suitable SMTP transport; if it does not succeed, the router is
1217 configured to fail the address.
1219 The second router is reached only when the domain is recognized as one that
1220 &"belongs"& to the local host. This router does redirection &-- also known as
1221 aliasing and forwarding. When it generates one or more new addresses from the
1222 original, each of them is routed independently from the start. Otherwise, the
1223 router may cause an address to fail, or it may simply decline to handle the
1224 address, in which case the address is passed to the next router.
1226 The final router in many configurations is one that checks to see if the
1227 address belongs to a local mailbox. The precondition may involve a check to
1228 see if the local part is the name of a login account, or it may look up the
1229 local part in a file or a database. If its preconditions are not met, or if
1230 the router declines, we have reached the end of the routers. When this happens,
1231 the address is bounced.
1235 .section "Processing an address for verification" "SECID16"
1236 .cindex "router" "for verification"
1237 .cindex "verifying address" "overview"
1238 As well as being used to decide how to deliver to an address, Exim's routers
1239 are also used for &'address verification'&. Verification can be requested as
1240 one of the checks to be performed in an ACL for incoming messages, on both
1241 sender and recipient addresses, and it can be tested using the &%-bv%& and
1242 &%-bvs%& command line options.
1244 When an address is being verified, the routers are run in &"verify mode"&. This
1245 does not affect the way the routers work, but it is a state that can be
1246 detected. By this means, a router can be skipped or made to behave differently
1247 when verifying. A common example is a configuration in which the first router
1248 sends all messages to a message-scanning program, unless they have been
1249 previously scanned. Thus, the first router accepts all addresses without any
1250 checking, making it useless for verifying. Normally, the &%no_verify%& option
1251 would be set for such a router, causing it to be skipped in verify mode.
1256 .section "Running an individual router" "SECTrunindrou"
1257 .cindex "router" "running details"
1258 .cindex "preconditions" "checking"
1259 .cindex "router" "result of running"
1260 As explained in the example above, a number of preconditions are checked before
1261 running a router. If any are not met, the router is skipped, and the address is
1262 passed to the next router. When all the preconditions on a router &'are'& met,
1263 the router is run. What happens next depends on the outcome, which is one of
1264 the following:
1266 .ilist
1267 &'accept'&: The router accepts the address, and either assigns it to a
1268 transport, or generates one or more &"child"& addresses. Processing the
1269 original address ceases,
1270 .oindex "&%unseen%&"
1271 unless the &%unseen%& option is set on the router. This option
1272 can be used to set up multiple deliveries with different routing (for example,
1273 for keeping archive copies of messages). When &%unseen%& is set, the address is
1274 passed to the next router. Normally, however, an &'accept'& return marks the
1275 end of routing.
1277 Any child addresses generated by the router are processed independently,
1278 starting with the first router by default. It is possible to change this by
1279 setting the &%redirect_router%& option to specify which router to start at for
1280 child addresses. Unlike &%pass_router%& (see below) the router specified by
1281 &%redirect_router%& may be anywhere in the router configuration.
1282 .next
1283 &'pass'&: The router recognizes the address, but cannot handle it itself. It
1284 requests that the address be passed to another router. By default the address
1285 is passed to the next router, but this can be changed by setting the
1286 &%pass_router%& option. However, (unlike &%redirect_router%&) the named router
1287 must be below the current router (to avoid loops).
1288 .next
1289 &'decline'&: The router declines to accept the address because it does not
1290 recognize it at all. By default, the address is passed to the next router, but
1291 this can be prevented by setting the &%no_more%& option. When &%no_more%& is
1292 set, all the remaining routers are skipped. In effect, &%no_more%& converts
1293 &'decline'& into &'fail'&.
1294 .next
1295 &'fail'&: The router determines that the address should fail, and queues it for
1296 the generation of a bounce message. There is no further processing of the
1297 original address unless &%unseen%& is set on the router.
1298 .next
1299 &'defer'&: The router cannot handle the address at the present time. (A
1300 database may be offline, or a DNS lookup may have timed out.) No further
1301 processing of the address happens in this delivery attempt. It is tried again
1302 next time the message is considered for delivery.
1303 .next
1304 &'error'&: There is some error in the router (for example, a syntax error in
1305 its configuration). The action is as for defer.
1306 .endlist
1308 If an address reaches the end of the routers without having been accepted by
1309 any of them, it is bounced as unrouteable. The default error message in this
1310 situation is &"unrouteable address"&, but you can set your own message by
1311 making use of the &%cannot_route_message%& option. This can be set for any
1312 router; the value from the last router that &"saw"& the address is used.
1314 Sometimes while routing you want to fail a delivery when some conditions are
1315 met but others are not, instead of passing the address on for further routing.
1316 You can do this by having a second router that explicitly fails the delivery
1317 when the relevant conditions are met. The &(redirect)& router has a &"fail"&
1318 facility for this purpose.
1321 .section "Duplicate addresses" "SECID17"
1322 .cindex "case of local parts"
1323 .cindex "address duplicate, discarding"
1324 .cindex "duplicate addresses"
1325 Once routing is complete, Exim scans the addresses that are assigned to local
1326 and remote transports, and discards any duplicates that it finds. During this
1327 check, local parts are treated as case-sensitive. This happens only when
1328 actually delivering a message; when testing routers with &%-bt%&, all the
1329 routed addresses are shown.
1333 .section "Router preconditions" "SECTrouprecon"
1334 .cindex "router" "preconditions, order of processing"
1335 .cindex "preconditions" "order of processing"
1336 The preconditions that are tested for each router are listed below, in the
1337 order in which they are tested. The individual configuration options are
1338 described in more detail in chapter &<<CHAProutergeneric>>&.
1340 .ilist
1341 The &%local_part_prefix%& and &%local_part_suffix%& options can specify that
1342 the local parts handled by the router may or must have certain prefixes and/or
1343 suffixes. If a mandatory affix (prefix or suffix) is not present, the router is
1344 skipped. These conditions are tested first. When an affix is present, it is
1345 removed from the local part before further processing, including the evaluation
1346 of any other conditions.
1347 .next
1348 Routers can be designated for use only when not verifying an address, that is,
1349 only when routing it for delivery (or testing its delivery routing). If the
1350 &%verify%& option is set false, the router is skipped when Exim is verifying an
1351 address.
1352 Setting the &%verify%& option actually sets two options, &%verify_sender%& and
1353 &%verify_recipient%&, which independently control the use of the router for
1354 sender and recipient verification. You can set these options directly if
1355 you want a router to be used for only one type of verification.
1356 .next
1357 If the &%address_test%& option is set false, the router is skipped when Exim is
1358 run with the &%-bt%& option to test an address routing. This can be helpful
1359 when the first router sends all new messages to a scanner of some sort; it
1360 makes it possible to use &%-bt%& to test subsequent delivery routing without
1361 having to simulate the effect of the scanner.
1362 .next
1363 Routers can be designated for use only when verifying an address, as
1364 opposed to routing it for delivery. The &%verify_only%& option controls this.
1365 .next
1366 Individual routers can be explicitly skipped when running the routers to
1367 check an address given in the SMTP EXPN command (see the &%expn%& option).
1368 .next
1369 If the &%domains%& option is set, the domain of the address must be in the set
1370 of domains that it defines.
1371 .next
1372 .vindex "&$local_part_prefix$&"
1373 .vindex "&$local_part$&"
1374 .vindex "&$local_part_suffix$&"
1375 If the &%local_parts%& option is set, the local part of the address must be in
1376 the set of local parts that it defines. If &%local_part_prefix%& or
1377 &%local_part_suffix%& is in use, the prefix or suffix is removed from the local
1378 part before this check. If you want to do precondition tests on local parts
1379 that include affixes, you can do so by using a &%condition%& option (see below)
1380 that uses the variables &$local_part$&, &$local_part_prefix$&, and
1381 &$local_part_suffix$& as necessary.
1382 .next
1383 .vindex "&$local_user_uid$&"
1384 .vindex "&$local_user_gid$&"
1385 .vindex "&$home$&"
1386 If the &%check_local_user%& option is set, the local part must be the name of
1387 an account on the local host. If this check succeeds, the uid and gid of the
1388 local user are placed in &$local_user_uid$& and &$local_user_gid$& and the
1389 user's home directory is placed in &$home$&; these values can be used in the
1390 remaining preconditions.
1391 .next
1392 If the &%router_home_directory%& option is set, it is expanded at this point,
1393 because it overrides the value of &$home$&. If this expansion were left till
1394 later, the value of &$home$& as set by &%check_local_user%& would be used in
1395 subsequent tests. Having two different values of &$home$& in the same router
1396 could lead to confusion.
1397 .next
1398 If the &%senders%& option is set, the envelope sender address must be in the
1399 set of addresses that it defines.
1400 .next
1401 If the &%require_files%& option is set, the existence or non-existence of
1402 specified files is tested.
1403 .next
1404 .cindex "customizing" "precondition"
1405 If the &%condition%& option is set, it is evaluated and tested. This option
1406 uses an expanded string to allow you to set up your own custom preconditions.
1407 Expanded strings are described in chapter &<<CHAPexpand>>&.
1408 .endlist
1411 Note that &%require_files%& comes near the end of the list, so you cannot use
1412 it to check for the existence of a file in which to lookup up a domain, local
1413 part, or sender. However, as these options are all expanded, you can use the
1414 &%exists%& expansion condition to make such tests within each condition. The
1415 &%require_files%& option is intended for checking files that the router may be
1416 going to use internally, or which are needed by a specific transport (for
1417 example, &_.procmailrc_&).
1421 .section "Delivery in detail" "SECID18"
1422 .cindex "delivery" "in detail"
1423 When a message is to be delivered, the sequence of events is as follows:
1425 .ilist
1426 If a system-wide filter file is specified, the message is passed to it. The
1427 filter may add recipients to the message, replace the recipients, discard the
1428 message, cause a new message to be generated, or cause the message delivery to
1429 fail. The format of the system filter file is the same as for Exim user filter
1430 files, described in the separate document entitled &'Exim's interfaces to mail
1431 filtering'&.
1432 .cindex "Sieve filter" "not available for system filter"
1433 (&*Note*&: Sieve cannot be used for system filter files.)
1435 Some additional features are available in system filters &-- see chapter
1436 &<<CHAPsystemfilter>>& for details. Note that a message is passed to the system
1437 filter only once per delivery attempt, however many recipients it has. However,
1438 if there are several delivery attempts because one or more addresses could not
1439 be immediately delivered, the system filter is run each time. The filter
1440 condition &%first_delivery%& can be used to detect the first run of the system
1441 filter.
1442 .next
1443 Each recipient address is offered to each configured router in turn, subject to
1444 its preconditions, until one is able to handle it. If no router can handle the
1445 address, that is, if they all decline, the address is failed. Because routers
1446 can be targeted at particular domains, several locally handled domains can be
1447 processed entirely independently of each other.
1448 .next
1449 .cindex "routing" "loops in"
1450 .cindex "loop" "while routing"
1451 A router that accepts an address may assign it to a local or a remote
1452 transport. However, the transport is not run at this time. Instead, the address
1453 is placed on a list for the particular transport, which will be run later.
1454 Alternatively, the router may generate one or more new addresses (typically
1455 from alias, forward, or filter files). New addresses are fed back into this
1456 process from the top, but in order to avoid loops, a router ignores any address
1457 which has an identically-named ancestor that was processed by itself.
1458 .next
1459 When all the routing has been done, addresses that have been successfully
1460 handled are passed to their assigned transports. When local transports are
1461 doing real local deliveries, they handle only one address at a time, but if a
1462 local transport is being used as a pseudo-remote transport (for example, to
1463 collect batched SMTP messages for transmission by some other means) multiple
1464 addresses can be handled. Remote transports can always handle more than one
1465 address at a time, but can be configured not to do so, or to restrict multiple
1466 addresses to the same domain.
1467 .next
1468 Each local delivery to a file or a pipe runs in a separate process under a
1469 non-privileged uid, and these deliveries are run one at a time. Remote
1470 deliveries also run in separate processes, normally under a uid that is private
1471 to Exim (&"the Exim user"&), but in this case, several remote deliveries can be
1472 run in parallel. The maximum number of simultaneous remote deliveries for any
1473 one message is set by the &%remote_max_parallel%& option.
1474 The order in which deliveries are done is not defined, except that all local
1475 deliveries happen before any remote deliveries.
1476 .next
1477 .cindex "queue runner"
1478 When it encounters a local delivery during a queue run, Exim checks its retry
1479 database to see if there has been a previous temporary delivery failure for the
1480 address before running the local transport. If there was a previous failure,
1481 Exim does not attempt a new delivery until the retry time for the address is
1482 reached. However, this happens only for delivery attempts that are part of a
1483 queue run. Local deliveries are always attempted when delivery immediately
1484 follows message reception, even if retry times are set for them. This makes for
1485 better behaviour if one particular message is causing problems (for example,
1486 causing quota overflow, or provoking an error in a filter file).
1487 .next
1488 .cindex "delivery" "retry in remote transports"
1489 Remote transports do their own retry handling, since an address may be
1490 deliverable to one of a number of hosts, each of which may have a different
1491 retry time. If there have been previous temporary failures and no host has
1492 reached its retry time, no delivery is attempted, whether in a queue run or
1493 not. See chapter &<<CHAPretry>>& for details of retry strategies.
1494 .next
1495 If there were any permanent errors, a bounce message is returned to an
1496 appropriate address (the sender in the common case), with details of the error
1497 for each failing address. Exim can be configured to send copies of bounce
1498 messages to other addresses.
1499 .next
1500 .cindex "delivery" "deferral"
1501 If one or more addresses suffered a temporary failure, the message is left on
1502 the queue, to be tried again later. Delivery of these addresses is said to be
1503 &'deferred'&.
1504 .next
1505 When all the recipient addresses have either been delivered or bounced,
1506 handling of the message is complete. The spool files and message log are
1507 deleted, though the message log can optionally be preserved if required.
1508 .endlist
1513 .section "Retry mechanism" "SECID19"
1514 .cindex "delivery" "retry mechanism"
1515 .cindex "retry" "description of mechanism"
1516 .cindex "queue runner"
1517 Exim's mechanism for retrying messages that fail to get delivered at the first
1518 attempt is the queue runner process. You must either run an Exim daemon that
1519 uses the &%-q%& option with a time interval to start queue runners at regular
1520 intervals, or use some other means (such as &'cron'&) to start them. If you do
1521 not arrange for queue runners to be run, messages that fail temporarily at the
1522 first attempt will remain on your queue for ever. A queue runner process works
1523 its way through the queue, one message at a time, trying each delivery that has
1524 passed its retry time.
1525 You can run several queue runners at once.
1527 Exim uses a set of configured rules to determine when next to retry the failing
1528 address (see chapter &<<CHAPretry>>&). These rules also specify when Exim
1529 should give up trying to deliver to the address, at which point it generates a
1530 bounce message. If no retry rules are set for a particular host, address, and
1531 error combination, no retries are attempted, and temporary errors are treated
1532 as permanent.
1536 .section "Temporary delivery failure" "SECID20"
1537 .cindex "delivery" "temporary failure"
1538 There are many reasons why a message may not be immediately deliverable to a
1539 particular address. Failure to connect to a remote machine (because it, or the
1540 connection to it, is down) is one of the most common. Temporary failures may be
1541 detected during routing as well as during the transport stage of delivery.
1542 Local deliveries may be delayed if NFS files are unavailable, or if a mailbox
1543 is on a file system where the user is over quota. Exim can be configured to
1544 impose its own quotas on local mailboxes; where system quotas are set they will
1545 also apply.
1547 If a host is unreachable for a period of time, a number of messages may be
1548 waiting for it by the time it recovers, and sending them in a single SMTP
1549 connection is clearly beneficial. Whenever a delivery to a remote host is
1550 deferred,
1552 .cindex "hints database"
1553 Exim makes a note in its hints database, and whenever a successful
1554 SMTP delivery has happened, it looks to see if any other messages are waiting
1555 for the same host. If any are found, they are sent over the same SMTP
1556 connection, subject to a configuration limit as to the maximum number in any
1557 one connection.
1562 .section "Permanent delivery failure" "SECID21"
1563 .cindex "delivery" "permanent failure"
1564 .cindex "bounce message" "when generated"
1565 When a message cannot be delivered to some or all of its intended recipients, a
1566 bounce message is generated. Temporary delivery failures turn into permanent
1567 errors when their timeout expires. All the addresses that fail in a given
1568 delivery attempt are listed in a single message. If the original message has
1569 many recipients, it is possible for some addresses to fail in one delivery
1570 attempt and others to fail subsequently, giving rise to more than one bounce
1571 message. The wording of bounce messages can be customized by the administrator.
1572 See chapter &<<CHAPemsgcust>>& for details.
1574 .cindex "&'X-Failed-Recipients:'& header line"
1575 Bounce messages contain an &'X-Failed-Recipients:'& header line that lists the
1576 failed addresses, for the benefit of programs that try to analyse such messages
1577 automatically.
1579 .cindex "bounce message" "recipient of"
1580 A bounce message is normally sent to the sender of the original message, as
1581 obtained from the message's envelope. For incoming SMTP messages, this is the
1582 address given in the MAIL command. However, when an address is expanded via a
1583 forward or alias file, an alternative address can be specified for delivery
1584 failures of the generated addresses. For a mailing list expansion (see section
1585 &<<SECTmailinglists>>&) it is common to direct bounce messages to the manager
1586 of the list.
1590 .section "Failures to deliver bounce messages" "SECID22"
1591 .cindex "bounce message" "failure to deliver"
1592 If a bounce message (either locally generated or received from a remote host)
1593 itself suffers a permanent delivery failure, the message is left on the queue,
1594 but it is frozen, awaiting the attention of an administrator. There are options
1595 that can be used to make Exim discard such failed messages, or to keep them
1596 for only a short time (see &%timeout_frozen_after%& and
1597 &%ignore_bounce_errors_after%&).
1603 . ////////////////////////////////////////////////////////////////////////////
1604 . ////////////////////////////////////////////////////////////////////////////
1606 .chapter "Building and installing Exim" "CHID3"
1607 .scindex IIDbuex "building Exim"
1609 .section "Unpacking" "SECID23"
1610 Exim is distributed as a gzipped or bzipped tar file which, when unpacked,
1611 creates a directory with the name of the current release (for example,
1612 &_exim-&version;_&) into which the following files are placed:
1614 .table2 140pt
1615 .irow &_ACKNOWLEDGMENTS_& "contains some acknowledgments"
1616 .irow &_CHANGES_& "contains a reference to where changes are &&&
1617 documented"
1618 .irow &_LICENCE_& "the GNU General Public Licence"
1619 .irow &_Makefile_& "top-level make file"
1620 .irow &_NOTICE_& "conditions for the use of Exim"
1621 .irow &_README_& "list of files, directories and simple build &&&
1622 instructions"
1623 .endtable
1625 Other files whose names begin with &_README_& may also be present. The
1626 following subdirectories are created:
1628 .table2 140pt
1629 .irow &_Local_& "an empty directory for local configuration files"
1630 .irow &_OS_& "OS-specific files"
1631 .irow &_doc_& "documentation files"
1632 .irow &_exim_monitor_& "source files for the Exim monitor"
1633 .irow &_scripts_& "scripts used in the build process"
1634 .irow &_src_& "remaining source files"
1635 .irow &_util_& "independent utilities"
1636 .endtable
1638 The main utility programs are contained in the &_src_& directory, and are built
1639 with the Exim binary. The &_util_& directory contains a few optional scripts
1640 that may be useful to some sites.
1643 .section "Multiple machine architectures and operating systems" "SECID24"
1644 .cindex "building Exim" "multiple OS/architectures"
1645 The building process for Exim is arranged to make it easy to build binaries for
1646 a number of different architectures and operating systems from the same set of
1647 source files. Compilation does not take place in the &_src_& directory.
1648 Instead, a &'build directory'& is created for each architecture and operating
1649 system.
1650 .cindex "symbolic link" "to build directory"
1651 Symbolic links to the sources are installed in this directory, which is where
1652 the actual building takes place. In most cases, Exim can discover the machine
1653 architecture and operating system for itself, but the defaults can be
1654 overridden if necessary.
1657 .section "PCRE library" "SECTdb"
1658 .cindex "PCRE library"
1659 Exim no longer has an embedded PCRE library as the vast majority of
1660 modern systems include PCRE as a system library, although you may need
1661 to install the PCRE or PCRE development package for your operating
1662 system. If your system has a normal PCRE installation the Exim build
1663 process will need no further configuration. If the library or the
1664 headers are in an unusual location you will need to set the PCRE_LIBS
1665 and INCLUDE directives appropriately. If your operating system has no
1666 PCRE support then you will need to obtain and build the current PCRE
1667 from &url(ftp://ftp.csx.cam.ac.uk/pub/software/programming/pcre/).
1669 .section "DBM libraries" "SECTdb"
1670 .cindex "DBM libraries" "discussion of"
1671 .cindex "hints database" "DBM files used for"
1672 Even if you do not use any DBM files in your configuration, Exim still needs a
1673 DBM library in order to operate, because it uses indexed files for its hints
1674 databases. Unfortunately, there are a number of DBM libraries in existence, and
1675 different operating systems often have different ones installed.
1677 .cindex "Solaris" "DBM library for"
1678 .cindex "IRIX, DBM library for"
1679 .cindex "BSD, DBM library for"
1680 .cindex "Linux, DBM library for"
1681 If you are using Solaris, IRIX, one of the modern BSD systems, or a modern
1682 Linux distribution, the DBM configuration should happen automatically, and you
1683 may be able to ignore this section. Otherwise, you may have to learn more than
1684 you would like about DBM libraries from what follows.
1686 .cindex "&'ndbm'& DBM library"
1687 Licensed versions of Unix normally contain a library of DBM functions operating
1688 via the &'ndbm'& interface, and this is what Exim expects by default. Free
1689 versions of Unix seem to vary in what they contain as standard. In particular,
1690 some early versions of Linux have no default DBM library, and different
1691 distributors have chosen to bundle different libraries with their packaged
1692 versions. However, the more recent releases seem to have standardized on the
1693 Berkeley DB library.
1695 Different DBM libraries have different conventions for naming the files they
1696 use. When a program opens a file called &_dbmfile_&, there are several
1697 possibilities:
1699 .olist
1700 A traditional &'ndbm'& implementation, such as that supplied as part of
1701 Solaris, operates on two files called &_dbmfile.dir_& and &_dbmfile.pag_&.
1702 .next
1703 .cindex "&'gdbm'& DBM library"
1704 The GNU library, &'gdbm'&, operates on a single file. If used via its &'ndbm'&
1705 compatibility interface it makes two different hard links to it with names
1706 &_dbmfile.dir_& and &_dbmfile.pag_&, but if used via its native interface, the
1707 file name is used unmodified.
1708 .next
1709 .cindex "Berkeley DB library"
1710 The Berkeley DB package, if called via its &'ndbm'& compatibility interface,
1711 operates on a single file called &_dbmfile.db_&, but otherwise looks to the
1712 programmer exactly the same as the traditional &'ndbm'& implementation.
1713 .next
1714 If the Berkeley package is used in its native mode, it operates on a single
1715 file called &_dbmfile_&; the programmer's interface is somewhat different to
1716 the traditional &'ndbm'& interface.
1717 .next
1718 To complicate things further, there are several very different versions of the
1719 Berkeley DB package. Version 1.85 was stable for a very long time, releases
1720 2.&'x'& and 3.&'x'& were current for a while, but the latest versions are now
1721 numbered 4.&'x'&. Maintenance of some of the earlier releases has ceased. All
1722 versions of Berkeley DB can be obtained from
1723 &url(http://www.sleepycat.com/).
1724 .next
1725 .cindex "&'tdb'& DBM library"
1726 Yet another DBM library, called &'tdb'&, is available from
1727 &url(http://download.sourceforge.net/tdb). It has its own interface, and also
1728 operates on a single file.
1729 .endlist
1731 .cindex "USE_DB"
1732 .cindex "DBM libraries" "configuration for building"
1733 Exim and its utilities can be compiled to use any of these interfaces. In order
1734 to use any version of the Berkeley DB package in native mode, you must set
1735 USE_DB in an appropriate configuration file (typically
1736 &_Local/Makefile_&). For example:
1737 .code
1738 USE_DB=yes
1739 .endd
1740 Similarly, for gdbm you set USE_GDBM, and for tdb you set USE_TDB. An
1741 error is diagnosed if you set more than one of these.
1743 At the lowest level, the build-time configuration sets none of these options,
1744 thereby assuming an interface of type (1). However, some operating system
1745 configuration files (for example, those for the BSD operating systems and
1746 Linux) assume type (4) by setting USE_DB as their default, and the
1747 configuration files for Cygwin set USE_GDBM. Anything you set in
1748 &_Local/Makefile_&, however, overrides these system defaults.
1750 As well as setting USE_DB, USE_GDBM, or USE_TDB, it may also be
1751 necessary to set DBMLIB, to cause inclusion of the appropriate library, as
1752 in one of these lines:
1753 .code
1754 DBMLIB = -ldb
1755 DBMLIB = -ltdb
1756 .endd
1757 Settings like that will work if the DBM library is installed in the standard
1758 place. Sometimes it is not, and the library's header file may also not be in
1759 the default path. You may need to set INCLUDE to specify where the header
1760 file is, and to specify the path to the library more fully in DBMLIB, as in
1761 this example:
1762 .code
1763 INCLUDE=-I/usr/local/include/db-4.1
1764 DBMLIB=/usr/local/lib/db-4.1/libdb.a
1765 .endd
1766 There is further detailed discussion about the various DBM libraries in the
1767 file &_doc/dbm.discuss.txt_& in the Exim distribution.
1771 .section "Pre-building configuration" "SECID25"
1772 .cindex "building Exim" "pre-building configuration"
1773 .cindex "configuration for building Exim"
1774 .cindex "&_Local/Makefile_&"
1775 .cindex "&_src/EDITME_&"
1776 Before building Exim, a local configuration file that specifies options
1777 independent of any operating system has to be created with the name
1778 &_Local/Makefile_&. A template for this file is supplied as the file
1779 &_src/EDITME_&, and it contains full descriptions of all the option settings
1780 therein. These descriptions are therefore not repeated here. If you are
1781 building Exim for the first time, the simplest thing to do is to copy
1782 &_src/EDITME_& to &_Local/Makefile_&, then read it and edit it appropriately.
1784 There are three settings that you must supply, because Exim will not build
1785 without them. They are the location of the run time configuration file
1786 (CONFIGURE_FILE), the directory in which Exim binaries will be installed
1787 (BIN_DIRECTORY), and the identity of the Exim user (EXIM_USER and
1788 maybe EXIM_GROUP as well). The value of CONFIGURE_FILE can in fact be
1789 a colon-separated list of file names; Exim uses the first of them that exists.
1791 There are a few other parameters that can be specified either at build time or
1792 at run time, to enable the same binary to be used on a number of different
1793 machines. However, if the locations of Exim's spool directory and log file
1794 directory (if not within the spool directory) are fixed, it is recommended that
1795 you specify them in &_Local/Makefile_& instead of at run time, so that errors
1796 detected early in Exim's execution (such as a malformed configuration file) can
1797 be logged.
1799 .cindex "content scanning" "specifying at build time"
1800 Exim's interfaces for calling virus and spam scanning software directly from
1801 access control lists are not compiled by default. If you want to include these
1802 facilities, you need to set
1803 .code
1805 .endd
1806 in your &_Local/Makefile_&. For details of the facilities themselves, see
1807 chapter &<<CHAPexiscan>>&.
1810 .cindex "&_Local/eximon.conf_&"
1811 .cindex "&_exim_monitor/EDITME_&"
1812 If you are going to build the Exim monitor, a similar configuration process is
1813 required. The file &_exim_monitor/EDITME_& must be edited appropriately for
1814 your installation and saved under the name &_Local/eximon.conf_&. If you are
1815 happy with the default settings described in &_exim_monitor/EDITME_&,
1816 &_Local/eximon.conf_& can be empty, but it must exist.
1818 This is all the configuration that is needed in straightforward cases for known
1819 operating systems. However, the building process is set up so that it is easy
1820 to override options that are set by default or by operating-system-specific
1821 configuration files, for example to change the name of the C compiler, which
1822 defaults to &%gcc%&. See section &<<SECToverride>>& below for details of how to
1823 do this.
1827 .section "Support for iconv()" "SECID26"
1828 .cindex "&[iconv()]& support"
1829 .cindex "RFC 2047"
1830 The contents of header lines in messages may be encoded according to the rules
1831 described RFC 2047. This makes it possible to transmit characters that are not
1832 in the ASCII character set, and to label them as being in a particular
1833 character set. When Exim is inspecting header lines by means of the &%$h_%&
1834 mechanism, it decodes them, and translates them into a specified character set
1835 (default ISO-8859-1). The translation is possible only if the operating system
1836 supports the &[iconv()]& function.
1838 However, some of the operating systems that supply &[iconv()]& do not support
1839 very many conversions. The GNU &%libiconv%& library (available from
1840 &url(http://www.gnu.org/software/libiconv/)) can be installed on such
1841 systems to remedy this deficiency, as well as on systems that do not supply
1842 &[iconv()]& at all. After installing &%libiconv%&, you should add
1843 .code
1844 HAVE_ICONV=yes
1845 .endd
1846 to your &_Local/Makefile_& and rebuild Exim.
1850 .section "Including TLS/SSL encryption support" "SECTinctlsssl"
1851 .cindex "TLS" "including support for TLS"
1852 .cindex "encryption" "including support for"
1853 .cindex "SUPPORT_TLS"
1854 .cindex "OpenSSL" "building Exim with"
1855 .cindex "GnuTLS" "building Exim with"
1856 Exim can be built to support encrypted SMTP connections, using the STARTTLS
1857 command as per RFC 2487. It can also support legacy clients that expect to
1858 start a TLS session immediately on connection to a non-standard port (see the
1859 &%tls_on_connect_ports%& runtime option and the &%-tls-on-connect%& command
1860 line option).
1862 If you want to build Exim with TLS support, you must first install either the
1863 OpenSSL or GnuTLS library. There is no cryptographic code in Exim itself for
1864 implementing SSL.
1866 If OpenSSL is installed, you should set
1867 .code
1868 SUPPORT_TLS=yes
1869 TLS_LIBS=-lssl -lcrypto
1870 .endd
1871 in &_Local/Makefile_&. You may also need to specify the locations of the
1872 OpenSSL library and include files. For example:
1873 .code
1874 SUPPORT_TLS=yes
1875 TLS_LIBS=-L/usr/local/openssl/lib -lssl -lcrypto
1876 TLS_INCLUDE=-I/usr/local/openssl/include/
1877 .endd
1878 .cindex "USE_GNUTLS"
1879 If GnuTLS is installed, you should set
1880 .code
1881 SUPPORT_TLS=yes
1882 USE_GNUTLS=yes
1883 TLS_LIBS=-lgnutls -ltasn1 -lgcrypt
1884 .endd
1885 in &_Local/Makefile_&, and again you may need to specify the locations of the
1886 library and include files. For example:
1887 .code
1888 SUPPORT_TLS=yes
1889 USE_GNUTLS=yes
1890 TLS_LIBS=-L/usr/gnu/lib -lgnutls -ltasn1 -lgcrypt
1891 TLS_INCLUDE=-I/usr/gnu/include
1892 .endd
1893 You do not need to set TLS_INCLUDE if the relevant directory is already
1894 specified in INCLUDE. Details of how to configure Exim to make use of TLS are
1895 given in chapter &<<CHAPTLS>>&.
1900 .section "Use of tcpwrappers" "SECID27"
1901 .cindex "tcpwrappers, building Exim to support"
1902 .cindex "USE_TCP_WRAPPERS"
1903 Exim can be linked with the &'tcpwrappers'& library in order to check incoming
1904 SMTP calls using the &'tcpwrappers'& control files. This may be a convenient
1905 alternative to Exim's own checking facilities for installations that are
1906 already making use of &'tcpwrappers'& for other purposes. To do this, you
1907 should set USE_TCP_WRAPPERS in &_Local/Makefile_&, arrange for the file
1908 &_tcpd.h_& to be available at compile time, and also ensure that the library
1909 &_libwrap.a_& is available at link time, typically by including &%-lwrap%& in
1910 EXTRALIBS_EXIM. For example, if &'tcpwrappers'& is installed in &_/usr/local_&,
1911 you might have
1912 .code
1914 CFLAGS=-O -I/usr/local/include
1915 EXTRALIBS_EXIM=-L/usr/local/lib -lwrap
1916 .endd
1917 in &_Local/Makefile_&. The name to use in the &'tcpwrappers'& control files is
1918 &"exim"&. For example, the line
1919 .code
1920 exim : LOCAL 192.168.1. .friendly.domain.example
1921 .endd
1922 in your &_/etc/hosts.allow_& file allows connections from the local host, from
1923 the subnet, and from all hosts in &'friendly.domain.example'&.
1924 All other connections are denied. Consult the &'tcpwrappers'& documentation for
1925 further details.
1929 .section "Including support for IPv6" "SECID28"
1930 .cindex "IPv6" "including support for"
1931 Exim contains code for use on systems that have IPv6 support. Setting
1932 &`HAVE_IPV6=YES`& in &_Local/Makefile_& causes the IPv6 code to be included;
1933 it may also be necessary to set IPV6_INCLUDE and IPV6_LIBS on systems
1934 where the IPv6 support is not fully integrated into the normal include and
1935 library files.
1937 Two different types of DNS record for handling IPv6 addresses have been
1938 defined. AAAA records (analogous to A records for IPv4) are in use, and are
1939 currently seen as the mainstream. Another record type called A6 was proposed
1940 as better than AAAA because it had more flexibility. However, it was felt to be
1941 over-complex, and its status was reduced to &"experimental"&. It is not known
1942 if anyone is actually using A6 records. Exim has support for A6 records, but
1943 this is included only if you set &`SUPPORT_A6=YES`& in &_Local/Makefile_&. The
1944 support has not been tested for some time.
1948 .section "The building process" "SECID29"
1949 .cindex "build directory"
1950 Once &_Local/Makefile_& (and &_Local/eximon.conf_&, if required) have been
1951 created, run &'make'& at the top level. It determines the architecture and
1952 operating system types, and creates a build directory if one does not exist.
1953 For example, on a Sun system running Solaris 8, the directory
1954 &_build-SunOS5-5.8-sparc_& is created.
1955 .cindex "symbolic link" "to source files"
1956 Symbolic links to relevant source files are installed in the build directory.
1958 &*Warning*&: The &%-j%& (parallel) flag must not be used with &'make'&; the
1959 building process fails if it is set.
1961 If this is the first time &'make'& has been run, it calls a script that builds
1962 a make file inside the build directory, using the configuration files from the
1963 &_Local_& directory. The new make file is then passed to another instance of
1964 &'make'&. This does the real work, building a number of utility scripts, and
1965 then compiling and linking the binaries for the Exim monitor (if configured), a
1966 number of utility programs, and finally Exim itself. The command &`make
1967 makefile`& can be used to force a rebuild of the make file in the build
1968 directory, should this ever be necessary.
1970 If you have problems building Exim, check for any comments there may be in the
1971 &_README_& file concerning your operating system, and also take a look at the
1972 FAQ, where some common problems are covered.
1976 .section 'Output from &"make"&' "SECID283"
1977 The output produced by the &'make'& process for compile lines is often very
1978 unreadable, because these lines can be very long. For this reason, the normal
1979 output is suppressed by default, and instead output similar to that which
1980 appears when compiling the 2.6 Linux kernel is generated: just a short line for
1981 each module that is being compiled or linked. However, it is still possible to
1982 get the full output, by calling &'make'& like this:
1983 .code
1984 FULLECHO='' make -e
1985 .endd
1986 The value of FULLECHO defaults to &"@"&, the flag character that suppresses
1987 command reflection in &'make'&. When you ask for the full output, it is
1988 given in addition to the short output.
1992 .section "Overriding build-time options for Exim" "SECToverride"
1993 .cindex "build-time options, overriding"
1994 The main make file that is created at the beginning of the building process
1995 consists of the concatenation of a number of files which set configuration
1996 values, followed by a fixed set of &'make'& instructions. If a value is set
1997 more than once, the last setting overrides any previous ones. This provides a
1998 convenient way of overriding defaults. The files that are concatenated are, in
1999 order:
2000 .display
2001 &_OS/Makefile-Default_&
2002 &_OS/Makefile-_&<&'ostype'&>
2003 &_Local/Makefile_&
2004 &_Local/Makefile-_&<&'ostype'&>
2005 &_Local/Makefile-_&<&'archtype'&>
2006 &_Local/Makefile-_&<&'ostype'&>-<&'archtype'&>
2007 &_OS/Makefile-Base_&
2008 .endd
2009 .cindex "&_Local/Makefile_&"
2010 .cindex "building Exim" "operating system type"
2011 .cindex "building Exim" "architecture type"
2012 where <&'ostype'&> is the operating system type and <&'archtype'&> is the
2013 architecture type. &_Local/Makefile_& is required to exist, and the building
2014 process fails if it is absent. The other three &_Local_& files are optional,
2015 and are often not needed.
2017 The values used for <&'ostype'&> and <&'archtype'&> are obtained from scripts
2018 called &_scripts/os-type_& and &_scripts/arch-type_& respectively. If either of
2019 the environment variables EXIM_OSTYPE or EXIM_ARCHTYPE is set, their
2020 values are used, thereby providing a means of forcing particular settings.
2021 Otherwise, the scripts try to get values from the &%uname%& command. If this
2022 fails, the shell variables OSTYPE and ARCHTYPE are inspected. A number
2023 of &'ad hoc'& transformations are then applied, to produce the standard names
2024 that Exim expects. You can run these scripts directly from the shell in order
2025 to find out what values are being used on your system.
2028 &_OS/Makefile-Default_& contains comments about the variables that are set
2029 therein. Some (but not all) are mentioned below. If there is something that
2030 needs changing, review the contents of this file and the contents of the make
2031 file for your operating system (&_OS/Makefile-<ostype>_&) to see what the
2032 default values are.
2035 .cindex "building Exim" "overriding default settings"
2036 If you need to change any of the values that are set in &_OS/Makefile-Default_&
2037 or in &_OS/Makefile-<ostype>_&, or to add any new definitions, you do not
2038 need to change the original files. Instead, you should make the changes by
2039 putting the new values in an appropriate &_Local_& file. For example,
2040 .cindex "Tru64-Unix build-time settings"
2041 when building Exim in many releases of the Tru64-Unix (formerly Digital UNIX,
2042 formerly DEC-OSF1) operating system, it is necessary to specify that the C
2043 compiler is called &'cc'& rather than &'gcc'&. Also, the compiler must be
2044 called with the option &%-std1%&, to make it recognize some of the features of
2045 Standard C that Exim uses. (Most other compilers recognize Standard C by
2046 default.) To do this, you should create a file called &_Local/Makefile-OSF1_&
2047 containing the lines
2048 .code
2049 CC=cc
2050 CFLAGS=-std1
2051 .endd
2052 If you are compiling for just one operating system, it may be easier to put
2053 these lines directly into &_Local/Makefile_&.
2055 Keeping all your local configuration settings separate from the distributed
2056 files makes it easy to transfer them to new versions of Exim simply by copying
2057 the contents of the &_Local_& directory.
2060 .cindex "NIS lookup type" "including support for"
2061 .cindex "NIS+ lookup type" "including support for"
2062 .cindex "LDAP" "including support for"
2063 .cindex "lookup" "inclusion in binary"
2064 Exim contains support for doing LDAP, NIS, NIS+, and other kinds of file
2065 lookup, but not all systems have these components installed, so the default is
2066 not to include the relevant code in the binary. All the different kinds of file
2067 and database lookup that Exim supports are implemented as separate code modules
2068 which are included only if the relevant compile-time options are set. In the
2069 case of LDAP, NIS, and NIS+, the settings for &_Local/Makefile_& are:
2070 .code
2071 LOOKUP_LDAP=yes
2072 LOOKUP_NIS=yes
2074 .endd
2075 and similar settings apply to the other lookup types. They are all listed in
2076 &_src/EDITME_&. In many cases the relevant include files and interface
2077 libraries need to be installed before compiling Exim.
2078 .cindex "cdb" "including support for"
2079 However, there are some optional lookup types (such as cdb) for which
2080 the code is entirely contained within Exim, and no external include
2081 files or libraries are required. When a lookup type is not included in the
2082 binary, attempts to configure Exim to use it cause run time configuration
2083 errors.
2085 .cindex "Perl" "including support for"
2086 Exim can be linked with an embedded Perl interpreter, allowing Perl
2087 subroutines to be called during string expansion. To enable this facility,
2088 .code
2089 EXIM_PERL=perl.o
2090 .endd
2091 must be defined in &_Local/Makefile_&. Details of this facility are given in
2092 chapter &<<CHAPperl>>&.
2094 .cindex "X11 libraries, location of"
2095 The location of the X11 libraries is something that varies a lot between
2096 operating systems, and there may be different versions of X11 to cope
2097 with. Exim itself makes no use of X11, but if you are compiling the Exim
2098 monitor, the X11 libraries must be available.
2099 The following three variables are set in &_OS/Makefile-Default_&:
2100 .code
2101 X11=/usr/X11R6
2102 XINCLUDE=-I$(X11)/include
2103 XLFLAGS=-L$(X11)/lib
2104 .endd
2105 These are overridden in some of the operating-system configuration files. For
2106 example, in &_OS/Makefile-SunOS5_& there is
2107 .code
2108 X11=/usr/openwin
2109 XINCLUDE=-I$(X11)/include
2110 XLFLAGS=-L$(X11)/lib -R$(X11)/lib
2111 .endd
2112 If you need to override the default setting for your operating system, place a
2113 definition of all three of these variables into your
2114 &_Local/Makefile-<ostype>_& file.
2116 .cindex "EXTRALIBS"
2117 If you need to add any extra libraries to the link steps, these can be put in a
2118 variable called EXTRALIBS, which appears in all the link commands, but by
2119 default is not defined. In contrast, EXTRALIBS_EXIM is used only on the
2120 command for linking the main Exim binary, and not for any associated utilities.
2122 .cindex "DBM libraries" "configuration for building"
2123 There is also DBMLIB, which appears in the link commands for binaries that
2124 use DBM functions (see also section &<<SECTdb>>&). Finally, there is
2125 EXTRALIBS_EXIMON, which appears only in the link step for the Exim monitor
2126 binary, and which can be used, for example, to include additional X11
2127 libraries.
2129 .cindex "configuration file" "editing"
2130 The make file copes with rebuilding Exim correctly if any of the configuration
2131 files are edited. However, if an optional configuration file is deleted, it is
2132 necessary to touch the associated non-optional file (that is,
2133 &_Local/Makefile_& or &_Local/eximon.conf_&) before rebuilding.
2136 .section "OS-specific header files" "SECID30"
2137 .cindex "&_os.h_&"
2138 .cindex "building Exim" "OS-specific C header files"
2139 The &_OS_& directory contains a number of files with names of the form
2140 &_os.h-<ostype>_&. These are system-specific C header files that should not
2141 normally need to be changed. There is a list of macro settings that are
2142 recognized in the file &_OS/os.configuring_&, which should be consulted if you
2143 are porting Exim to a new operating system.
2147 .section "Overriding build-time options for the monitor" "SECID31"
2148 .cindex "building Eximon"
2149 A similar process is used for overriding things when building the Exim monitor,
2150 where the files that are involved are
2151 .display
2152 &_OS/eximon.conf-Default_&
2153 &_OS/eximon.conf-_&<&'ostype'&>
2154 &_Local/eximon.conf_&
2155 &_Local/eximon.conf-_&<&'ostype'&>
2156 &_Local/eximon.conf-_&<&'archtype'&>
2157 &_Local/eximon.conf-_&<&'ostype'&>-<&'archtype'&>
2158 .endd
2159 .cindex "&_Local/eximon.conf_&"
2160 As with Exim itself, the final three files need not exist, and in this case the
2161 &_OS/eximon.conf-<ostype>_& file is also optional. The default values in
2162 &_OS/eximon.conf-Default_& can be overridden dynamically by setting environment
2163 variables of the same name, preceded by EXIMON_. For example, setting
2164 EXIMON_LOG_DEPTH in the environment overrides the value of
2165 LOG_DEPTH at run time.
2166 .ecindex IIDbuex
2169 .section "Installing Exim binaries and scripts" "SECID32"
2170 .cindex "installing Exim"
2171 .cindex "BIN_DIRECTORY"
2172 The command &`make install`& runs the &(exim_install)& script with no
2173 arguments. The script copies binaries and utility scripts into the directory
2174 whose name is specified by the BIN_DIRECTORY setting in &_Local/Makefile_&.
2175 .cindex "setuid" "installing Exim with"
2176 The install script copies files only if they are newer than the files they are
2177 going to replace. The Exim binary is required to be owned by root and have the
2178 &'setuid'& bit set, for normal configurations. Therefore, you must run &`make
2179 install`& as root so that it can set up the Exim binary in this way. However, in
2180 some special situations (for example, if a host is doing no local deliveries)
2181 it may be possible to run Exim without making the binary setuid root (see
2182 chapter &<<CHAPsecurity>>& for details).
2184 .cindex "CONFIGURE_FILE"
2185 Exim's run time configuration file is named by the CONFIGURE_FILE setting
2186 in &_Local/Makefile_&. If this names a single file, and the file does not
2187 exist, the default configuration file &_src/configure.default_& is copied there
2188 by the installation script. If a run time configuration file already exists, it
2189 is left alone. If CONFIGURE_FILE is a colon-separated list, naming several
2190 alternative files, no default is installed.
2192 .cindex "system aliases file"
2193 .cindex "&_/etc/aliases_&"
2194 One change is made to the default configuration file when it is installed: the
2195 default configuration contains a router that references a system aliases file.
2196 The path to this file is set to the value specified by
2197 SYSTEM_ALIASES_FILE in &_Local/Makefile_& (&_/etc/aliases_& by default).
2198 If the system aliases file does not exist, the installation script creates it,
2199 and outputs a comment to the user.
2201 The created file contains no aliases, but it does contain comments about the
2202 aliases a site should normally have. Mail aliases have traditionally been
2203 kept in &_/etc/aliases_&. However, some operating systems are now using
2204 &_/etc/mail/aliases_&. You should check if yours is one of these, and change
2205 Exim's configuration if necessary.
2207 The default configuration uses the local host's name as the only local domain,
2208 and is set up to do local deliveries into the shared directory &_/var/mail_&,
2209 running as the local user. System aliases and &_.forward_& files in users' home
2210 directories are supported, but no NIS or NIS+ support is configured. Domains
2211 other than the name of the local host are routed using the DNS, with delivery
2212 over SMTP.
2214 It is possible to install Exim for special purposes (such as building a binary
2215 distribution) in a private part of the file system. You can do this by a
2216 command such as
2217 .code
2218 make DESTDIR=/some/directory/ install
2219 .endd
2220 This has the effect of pre-pending the specified directory to all the file
2221 paths, except the name of the system aliases file that appears in the default
2222 configuration. (If a default alias file is created, its name &'is'& modified.)
2223 For backwards compatibility, ROOT is used if DESTDIR is not set,
2224 but this usage is deprecated.
2226 .cindex "installing Exim" "what is not installed"
2227 Running &'make install'& does not copy the Exim 4 conversion script
2228 &'convert4r4'&, or the &'pcretest'& test program. You will probably run the
2229 first of these only once (if you are upgrading from Exim 3), and the second
2230 isn't really part of Exim. None of the documentation files in the &_doc_&
2231 directory are copied, except for the info files when you have set
2232 INFO_DIRECTORY, as described in section &<<SECTinsinfdoc>>& below.
2234 For the utility programs, old versions are renamed by adding the suffix &_.O_&
2235 to their names. The Exim binary itself, however, is handled differently. It is
2236 installed under a name that includes the version number and the compile number,
2237 for example &_exim-&version;-1_&. The script then arranges for a symbolic link
2238 called &_exim_& to point to the binary. If you are updating a previous version
2239 of Exim, the script takes care to ensure that the name &_exim_& is never absent
2240 from the directory (as seen by other processes).
2242 .cindex "installing Exim" "testing the script"
2243 If you want to see what the &'make install'& will do before running it for
2244 real, you can pass the &%-n%& option to the installation script by this
2245 command:
2246 .code
2247 make INSTALL_ARG=-n install
2248 .endd
2249 The contents of the variable INSTALL_ARG are passed to the installation
2250 script. You do not need to be root to run this test. Alternatively, you can run
2251 the installation script directly, but this must be from within the build
2252 directory. For example, from the top-level Exim directory you could use this
2253 command:
2254 .code
2255 (cd build-SunOS5-5.5.1-sparc; ../scripts/exim_install -n)
2256 .endd
2257 .cindex "installing Exim" "install script options"
2258 There are two other options that can be supplied to the installation script.
2260 .ilist
2261 &%-no_chown%& bypasses the call to change the owner of the installed binary
2262 to root, and the call to make it a setuid binary.
2263 .next
2264 &%-no_symlink%& bypasses the setting up of the symbolic link &_exim_& to the
2265 installed binary.
2266 .endlist
2268 INSTALL_ARG can be used to pass these options to the script. For example:
2269 .code
2270 make INSTALL_ARG=-no_symlink install
2271 .endd
2272 The installation script can also be given arguments specifying which files are
2273 to be copied. For example, to install just the Exim binary, and nothing else,
2274 without creating the symbolic link, you could use:
2275 .code
2276 make INSTALL_ARG='-no_symlink exim' install
2277 .endd
2281 .section "Installing info documentation" "SECTinsinfdoc"
2282 .cindex "installing Exim" "&'info'& documentation"
2283 Not all systems use the GNU &'info'& system for documentation, and for this
2284 reason, the Texinfo source of Exim's documentation is not included in the main
2285 distribution. Instead it is available separately from the ftp site (see section
2286 &<<SECTavail>>&).
2288 If you have defined INFO_DIRECTORY in &_Local/Makefile_& and the Texinfo
2289 source of the documentation is found in the source tree, running &`make
2290 install`& automatically builds the info files and installs them.
2294 .section "Setting up the spool directory" "SECID33"
2295 .cindex "spool directory" "creating"
2296 When it starts up, Exim tries to create its spool directory if it does not
2297 exist. The Exim uid and gid are used for the owner and group of the spool
2298 directory. Sub-directories are automatically created in the spool directory as
2299 necessary.
2304 .section "Testing" "SECID34"
2305 .cindex "testing" "installation"
2306 Having installed Exim, you can check that the run time configuration file is
2307 syntactically valid by running the following command, which assumes that the
2308 Exim binary directory is within your PATH environment variable:
2309 .code
2310 exim -bV
2311 .endd
2312 If there are any errors in the configuration file, Exim outputs error messages.
2313 Otherwise it outputs the version number and build date,
2314 the DBM library that is being used, and information about which drivers and
2315 other optional code modules are included in the binary.
2316 Some simple routing tests can be done by using the address testing option. For
2317 example,
2318 .display
2319 &`exim -bt`& <&'local username'&>
2320 .endd
2321 should verify that it recognizes a local mailbox, and
2322 .display
2323 &`exim -bt`& <&'remote address'&>
2324 .endd
2325 a remote one. Then try getting it to deliver mail, both locally and remotely.
2326 This can be done by passing messages directly to Exim, without going through a
2327 user agent. For example:
2328 .code
2329 exim -v postmaster@your.domain.example
2330 From: user@your.domain.example
2331 To: postmaster@your.domain.example
2332 Subject: Testing Exim
2334 This is a test message.
2335 ^D
2336 .endd
2337 The &%-v%& option causes Exim to output some verification of what it is doing.
2338 In this case you should see copies of three log lines, one for the message's
2339 arrival, one for its delivery, and one containing &"Completed"&.
2341 .cindex "delivery" "problems with"
2342 If you encounter problems, look at Exim's log files (&'mainlog'& and
2343 &'paniclog'&) to see if there is any relevant information there. Another source
2344 of information is running Exim with debugging turned on, by specifying the
2345 &%-d%& option. If a message is stuck on Exim's spool, you can force a delivery
2346 with debugging turned on by a command of the form
2347 .display
2348 &`exim -d -M`& <&'exim-message-id'&>
2349 .endd
2350 You must be root or an &"admin user"& in order to do this. The &%-d%& option
2351 produces rather a lot of output, but you can cut this down to specific areas.
2352 For example, if you use &%-d-all+route%& only the debugging information
2353 relevant to routing is included. (See the &%-d%& option in chapter
2354 &<<CHAPcommandline>>& for more details.)
2356 .cindex '&"sticky"& bit'
2357 .cindex "lock files"
2358 One specific problem that has shown up on some sites is the inability to do
2359 local deliveries into a shared mailbox directory, because it does not have the
2360 &"sticky bit"& set on it. By default, Exim tries to create a lock file before
2361 writing to a mailbox file, and if it cannot create the lock file, the delivery
2362 is deferred. You can get round this either by setting the &"sticky bit"& on the
2363 directory, or by setting a specific group for local deliveries and allowing
2364 that group to create files in the directory (see the comments above the
2365 &(local_delivery)& transport in the default configuration file). Another
2366 approach is to configure Exim not to use lock files, but just to rely on
2367 &[fcntl()]& locking instead. However, you should do this only if all user
2368 agents also use &[fcntl()]& locking. For further discussion of locking issues,
2369 see chapter &<<CHAPappendfile>>&.
2371 One thing that cannot be tested on a system that is already running an MTA is
2372 the receipt of incoming SMTP mail on the standard SMTP port. However, the
2373 &%-oX%& option can be used to run an Exim daemon that listens on some other
2374 port, or &'inetd'& can be used to do this. The &%-bh%& option and the
2375 &'exim_checkaccess'& utility can be used to check out policy controls on
2376 incoming SMTP mail.
2378 Testing a new version on a system that is already running Exim can most easily
2379 be done by building a binary with a different CONFIGURE_FILE setting. From
2380 within the run time configuration, all other file and directory names
2381 that Exim uses can be altered, in order to keep it entirely clear of the
2382 production version.
2385 .section "Replacing another MTA with Exim" "SECID35"
2386 .cindex "replacing another MTA"
2387 Building and installing Exim for the first time does not of itself put it in
2388 general use. The name by which the system's MTA is called by mail user agents
2389 is either &_/usr/sbin/sendmail_&, or &_/usr/lib/sendmail_& (depending on the
2390 operating system), and it is necessary to make this name point to the &'exim'&
2391 binary in order to get the user agents to pass messages to Exim. This is
2392 normally done by renaming any existing file and making &_/usr/sbin/sendmail_&
2393 or &_/usr/lib/sendmail_&
2394 .cindex "symbolic link" "to &'exim'& binary"
2395 a symbolic link to the &'exim'& binary. It is a good idea to remove any setuid
2396 privilege and executable status from the old MTA. It is then necessary to stop
2397 and restart the mailer daemon, if one is running.
2399 .cindex "FreeBSD, MTA indirection"
2400 .cindex "&_/etc/mail/mailer.conf_&"
2401 Some operating systems have introduced alternative ways of switching MTAs. For
2402 example, if you are running FreeBSD, you need to edit the file
2403 &_/etc/mail/mailer.conf_& instead of setting up a symbolic link as just
2404 described. A typical example of the contents of this file for running Exim is
2405 as follows:
2406 .code
2407 sendmail /usr/exim/bin/exim
2408 send-mail /usr/exim/bin/exim
2409 mailq /usr/exim/bin/exim -bp
2410 newaliases /usr/bin/true
2411 .endd
2412 Once you have set up the symbolic link, or edited &_/etc/mail/mailer.conf_&,
2413 your Exim installation is &"live"&. Check it by sending a message from your
2414 favourite user agent.
2416 You should consider what to tell your users about the change of MTA. Exim may
2417 have different capabilities to what was previously running, and there are
2418 various operational differences such as the text of messages produced by
2419 command line options and in bounce messages. If you allow your users to make
2420 use of Exim's filtering capabilities, you should make the document entitled
2421 &'Exim's interface to mail filtering'& available to them.
2425 .section "Upgrading Exim" "SECID36"
2426 .cindex "upgrading Exim"
2427 If you are already running Exim on your host, building and installing a new
2428 version automatically makes it available to MUAs, or any other programs that
2429 call the MTA directly. However, if you are running an Exim daemon, you do need
2430 to send it a HUP signal, to make it re-execute itself, and thereby pick up the
2431 new binary. You do not need to stop processing mail in order to install a new
2432 version of Exim. The install script does not modify an existing runtime
2433 configuration file.
2438 .section "Stopping the Exim daemon on Solaris" "SECID37"
2439 .cindex "Solaris" "stopping Exim on"
2440 The standard command for stopping the mailer daemon on Solaris is
2441 .code
2442 /etc/init.d/sendmail stop
2443 .endd
2444 If &_/usr/lib/sendmail_& has been turned into a symbolic link, this script
2445 fails to stop Exim because it uses the command &'ps -e'& and greps the output
2446 for the text &"sendmail"&; this is not present because the actual program name
2447 (that is, &"exim"&) is given by the &'ps'& command with these options. A
2448 solution is to replace the line that finds the process id with something like
2449 .code
2450 pid=`cat /var/spool/exim/exim-daemon.pid`
2451 .endd
2452 to obtain the daemon's pid directly from the file that Exim saves it in.
2454 Note, however, that stopping the daemon does not &"stop Exim"&. Messages can
2455 still be received from local processes, and if automatic delivery is configured
2456 (the normal case), deliveries will still occur.
2461 . ////////////////////////////////////////////////////////////////////////////
2462 . ////////////////////////////////////////////////////////////////////////////
2464 .chapter "The Exim command line" "CHAPcommandline"
2465 .scindex IIDclo1 "command line" "options"
2466 .scindex IIDclo2 "options" "command line"
2467 Exim's command line takes the standard Unix form of a sequence of options,
2468 each starting with a hyphen character, followed by a number of arguments. The
2469 options are compatible with the main options of Sendmail, and there are also
2470 some additional options, some of which are compatible with Smail 3. Certain
2471 combinations of options do not make sense, and provoke an error if used.
2472 The form of the arguments depends on which options are set.
2475 .section "Setting options by program name" "SECID38"
2476 .cindex "&'mailq'&"
2477 If Exim is called under the name &'mailq'&, it behaves as if the option &%-bp%&
2478 were present before any other options.
2479 The &%-bp%& option requests a listing of the contents of the mail queue on the
2480 standard output.
2481 This feature is for compatibility with some systems that contain a command of
2482 that name in one of the standard libraries, symbolically linked to
2483 &_/usr/sbin/sendmail_& or &_/usr/lib/sendmail_&.
2485 .cindex "&'rsmtp'&"
2486 If Exim is called under the name &'rsmtp'& it behaves as if the option &%-bS%&
2487 were present before any other options, for compatibility with Smail. The
2488 &%-bS%& option is used for reading in a number of messages in batched SMTP
2489 format.
2491 .cindex "&'rmail'&"
2492 If Exim is called under the name &'rmail'& it behaves as if the &%-i%& and
2493 &%-oee%& options were present before any other options, for compatibility with
2494 Smail. The name &'rmail'& is used as an interface by some UUCP systems.
2496 .cindex "&'runq'&"
2497 .cindex "queue runner"
2498 If Exim is called under the name &'runq'& it behaves as if the option &%-q%&
2499 were present before any other options, for compatibility with Smail. The &%-q%&
2500 option causes a single queue runner process to be started.
2502 .cindex "&'newaliases'&"
2503 .cindex "alias file" "building"
2504 .cindex "Sendmail compatibility" "calling Exim as &'newaliases'&"
2505 If Exim is called under the name &'newaliases'& it behaves as if the option
2506 &%-bi%& were present before any other options, for compatibility with Sendmail.
2507 This option is used for rebuilding Sendmail's alias file. Exim does not have
2508 the concept of a single alias file, but can be configured to run a given
2509 command if called with the &%-bi%& option.
2512 .section "Trusted and admin users" "SECTtrustedadmin"
2513 Some Exim options are available only to &'trusted users'& and others are
2514 available only to &'admin users'&. In the description below, the phrases &"Exim
2515 user"& and &"Exim group"& mean the user and group defined by EXIM_USER and
2516 EXIM_GROUP in &_Local/Makefile_& or set by the &%exim_user%& and
2517 &%exim_group%& options. These do not necessarily have to use the name &"exim"&.
2519 .ilist
2520 .cindex "trusted users" "definition of"
2521 .cindex "user" "trusted definition of"
2522 The trusted users are root, the Exim user, any user listed in the
2523 &%trusted_users%& configuration option, and any user whose current group or any
2524 supplementary group is one of those listed in the &%trusted_groups%&
2525 configuration option. Note that the Exim group is not automatically trusted.
2527 .cindex '&"From"& line'
2528 .cindex "envelope sender"
2529 Trusted users are always permitted to use the &%-f%& option or a leading
2530 &"From&~"& line to specify the envelope sender of a message that is passed to
2531 Exim through the local interface (see the &%-bm%& and &%-f%& options below).
2532 See the &%untrusted_set_sender%& option for a way of permitting non-trusted
2533 users to set envelope senders.
2535 .cindex "&'From:'& header line"
2536 .cindex "&'Sender:'& header line"
2537 For a trusted user, there is never any check on the contents of the &'From:'&
2538 header line, and a &'Sender:'& line is never added. Furthermore, any existing
2539 &'Sender:'& line in incoming local (non-TCP/IP) messages is not removed.
2541 Trusted users may also specify a host name, host address, interface address,
2542 protocol name, ident value, and authentication data when submitting a message
2543 locally. Thus, they are able to insert messages into Exim's queue locally that
2544 have the characteristics of messages received from a remote host. Untrusted
2545 users may in some circumstances use &%-f%&, but can never set the other values
2546 that are available to trusted users.
2547 .next
2548 .cindex "user" "admin definition of"
2549 .cindex "admin user" "definition of"
2550 The admin users are root, the Exim user, and any user that is a member of the
2551 Exim group or of any group listed in the &%admin_groups%& configuration option.
2552 The current group does not have to be one of these groups.
2554 Admin users are permitted to list the queue, and to carry out certain
2555 operations on messages, for example, to force delivery failures. It is also
2556 necessary to be an admin user in order to see the full information provided by
2557 the Exim monitor, and full debugging output.
2559 By default, the use of the &%-M%&, &%-q%&, &%-R%&, and &%-S%& options to cause
2560 Exim to attempt delivery of messages on its queue is restricted to admin users.
2561 However, this restriction can be relaxed by setting the &%prod_requires_admin%&
2562 option false (that is, specifying &%no_prod_requires_admin%&).
2564 Similarly, the use of the &%-bp%& option to list all the messages in the queue
2565 is restricted to admin users unless &%queue_list_requires_admin%& is set
2566 false.
2567 .endlist
2570 &*Warning*&: If you configure your system so that admin users are able to
2571 edit Exim's configuration file, you are giving those users an easy way of
2572 getting root. There is further discussion of this issue at the start of chapter
2573 &<<CHAPconf>>&.
2578 .section "Command line options" "SECID39"
2579 Exim's command line options are described in alphabetical order below. If none
2580 of the options that specifies a specific action (such as starting the daemon or
2581 a queue runner, or testing an address, or receiving a message in a specific
2582 format, or listing the queue) are present, and there is at least one argument
2583 on the command line, &%-bm%& (accept a local message on the standard input,
2584 with the arguments specifying the recipients) is assumed. Otherwise, Exim
2585 outputs a brief message about itself and exits.
2587 . ////////////////////////////////////////////////////////////////////////////
2588 . Insert a stylized XML comment here, to identify the start of the command line
2589 . options. This is for the benefit of the Perl script that automatically
2590 . creates a man page for the options.
2591 . ////////////////////////////////////////////////////////////////////////////
2593 .literal xml
2594 <!-- === Start of command line options === -->
2595 .literal off
2598 .vlist
2599 .vitem &%--%&
2600 .oindex "--"
2601 .cindex "options" "command line; terminating"
2602 This is a pseudo-option whose only purpose is to terminate the options and
2603 therefore to cause subsequent command line items to be treated as arguments
2604 rather than options, even if they begin with hyphens.
2606 .vitem &%--help%&
2607 .oindex "&%--help%&"
2608 This option causes Exim to output a few sentences stating what it is.
2609 The same output is generated if the Exim binary is called with no options and
2610 no arguments.
2612 .vitem &%-B%&<&'type'&>
2613 .oindex "&%-B%&"
2614 .cindex "8-bit characters"
2615 .cindex "Sendmail compatibility" "8-bit characters"
2616 This is a Sendmail option for selecting 7 or 8 bit processing. Exim is 8-bit
2617 clean; it ignores this option.
2619 .vitem &%-bd%&
2620 .oindex "&%-bd%&"
2621 .cindex "daemon"
2622 .cindex "SMTP" "listener"
2623 .cindex "queue runner"
2624 This option runs Exim as a daemon, awaiting incoming SMTP connections. Usually
2625 the &%-bd%& option is combined with the &%-q%&<&'time'&> option, to specify
2626 that the daemon should also initiate periodic queue runs.
2628 The &%-bd%& option can be used only by an admin user. If either of the &%-d%&
2629 (debugging) or &%-v%& (verifying) options are set, the daemon does not
2630 disconnect from the controlling terminal. When running this way, it can be
2631 stopped by pressing ctrl-C.
2633 By default, Exim listens for incoming connections to the standard SMTP port on
2634 all the host's running interfaces. However, it is possible to listen on other
2635 ports, on multiple ports, and only on specific interfaces. Chapter
2636 &<<CHAPinterfaces>>& contains a description of the options that control this.
2638 When a listening daemon
2639 .cindex "daemon" "process id (pid)"
2640 .cindex "pid (process id)" "of daemon"
2641 is started without the use of &%-oX%& (that is, without overriding the normal
2642 configuration), it writes its process id to a file called &_exim-daemon.pid_&
2643 in Exim's spool directory. This location can be overridden by setting
2644 PID_FILE_PATH in &_Local/Makefile_&. The file is written while Exim is still
2645 running as root.
2647 When &%-oX%& is used on the command line to start a listening daemon, the
2648 process id is not written to the normal pid file path. However, &%-oP%& can be
2649 used to specify a path on the command line if a pid file is required.
2651 The SIGHUP signal
2652 .cindex "SIGHUP"
2653 .cindex "daemon" "restarting"
2654 can be used to cause the daemon to re-execute itself. This should be done
2655 whenever Exim's configuration file, or any file that is incorporated into it by
2656 means of the &%.include%& facility, is changed, and also whenever a new version
2657 of Exim is installed. It is not necessary to do this when other files that are
2658 referenced from the configuration (for example, alias files) are changed,
2659 because these are reread each time they are used.
2661 .vitem &%-bdf%&
2662 .oindex "&%-bdf%&"
2663 This option has the same effect as &%-bd%& except that it never disconnects
2664 from the controlling terminal, even when no debugging is specified.
2666 .vitem &%-be%&
2667 .oindex "&%-be%&"
2668 .cindex "testing" "string expansion"
2669 .cindex "expansion" "testing"
2670 Run Exim in expansion testing mode. Exim discards its root privilege, to
2671 prevent ordinary users from using this mode to read otherwise inaccessible
2672 files. If no arguments are given, Exim runs interactively, prompting for lines
2673 of data. Otherwise, it processes each argument in turn.
2675 If Exim was built with USE_READLINE=yes in &_Local/Makefile_&, it tries
2676 to load the &%libreadline%& library dynamically whenever the &%-be%& option is
2677 used without command line arguments. If successful, it uses the &[readline()]&
2678 function, which provides extensive line-editing facilities, for reading the
2679 test data. A line history is supported.
2681 Long expansion expressions can be split over several lines by using backslash
2682 continuations. As in Exim's run time configuration, white space at the start of
2683 continuation lines is ignored. Each argument or data line is passed through the
2684 string expansion mechanism, and the result is output. Variable values from the
2685 configuration file (for example, &$qualify_domain$&) are available, but no
2686 message-specific values (such as &$sender_domain$&) are set, because no message
2687 is being processed (but see &%-bem%& and &%-Mset%&).
2689 &*Note*&: If you use this mechanism to test lookups, and you change the data
2690 files or databases you are using, you must exit and restart Exim before trying
2691 the same lookup again. Otherwise, because each Exim process caches the results
2692 of lookups, you will just get the same result as before.
2694 .vitem &%-bem%&&~<&'filename'&>
2695 .oindex "&%-bem%&"
2696 .cindex "testing" "string expansion"
2697 .cindex "expansion" "testing"
2698 This option operates like &%-be%& except that it must be followed by the name
2699 of a file. For example:
2700 .code
2701 exim -bem /tmp/testmessage
2702 .endd
2703 The file is read as a message (as if receiving a locally-submitted non-SMTP
2704 message) before any of the test expansions are done. Thus, message-specific
2705 variables such as &$message_size$& and &$header_from:$& are available. However,
2706 no &'Received:'& header is added to the message. If the &%-t%& option is set,
2707 recipients are read from the headers in the normal way, and are shown in the
2708 &$recipients$& variable. Note that recipients cannot be given on the command
2709 line, because further arguments are taken as strings to expand (just like
2710 &%-be%&).
2712 .vitem &%-bF%&&~<&'filename'&>
2713 .oindex "&%-bF%&"
2714 .cindex "system filter" "testing"
2715 .cindex "testing" "system filter"
2716 This option is the same as &%-bf%& except that it assumes that the filter being
2717 tested is a system filter. The additional commands that are available only in
2718 system filters are recognized.
2720 .vitem &%-bf%&&~<&'filename'&>
2721 .oindex "&%-bf%&"
2722 .cindex "filter" "testing"
2723 .cindex "testing" "filter file"
2724 .cindex "forward file" "testing"
2725 .cindex "testing" "forward file"
2726 .cindex "Sieve filter" "testing"
2727 This option runs Exim in user filter testing mode; the file is the filter file
2728 to be tested, and a test message must be supplied on the standard input. If
2729 there are no message-dependent tests in the filter, an empty file can be
2730 supplied.
2732 If you want to test a system filter file, use &%-bF%& instead of &%-bf%&. You
2733 can use both &%-bF%& and &%-bf%& on the same command, in order to test a system
2734 filter and a user filter in the same run. For example:
2735 .code
2736 exim -bF /system/filter -bf /user/filter </test/message
2737 .endd
2738 This is helpful when the system filter adds header lines or sets filter
2739 variables that are used by the user filter.
2741 If the test filter file does not begin with one of the special lines
2742 .code
2743 # Exim filter
2744 # Sieve filter
2745 .endd
2746 it is taken to be a normal &_.forward_& file, and is tested for validity under
2747 that interpretation. See sections &<<SECTitenonfilred>>& to
2748 &<<SECTspecitredli>>& for a description of the possible contents of non-filter
2749 redirection lists.
2751 The result of an Exim command that uses &%-bf%&, provided no errors are
2752 detected, is a list of the actions that Exim would try to take if presented
2753 with the message for real. More details of filter testing are given in the
2754 separate document entitled &'Exim's interfaces to mail filtering'&.
2756 When testing a filter file,
2757 .cindex "&""From""& line"
2758 .cindex "envelope sender"
2759 .oindex "&%-f%&" "for filter testing"
2760 the envelope sender can be set by the &%-f%& option,
2761 or by a &"From&~"& line at the start of the test message. Various parameters
2762 that would normally be taken from the envelope recipient address of the message
2763 can be set by means of additional command line options (see the next four
2764 options).
2766 .vitem &%-bfd%&&~<&'domain'&>
2767 .oindex "&%-bfd%&"
2768 .vindex "&$qualify_domain$&"
2769 This sets the domain of the recipient address when a filter file is being
2770 tested by means of the &%-bf%& option. The default is the value of
2771 &$qualify_domain$&.
2773 .vitem &%-bfl%&&~<&'local&~part'&>
2774 .oindex "&%-bfl%&"
2775 This sets the local part of the recipient address when a filter file is being
2776 tested by means of the &%-bf%& option. The default is the username of the
2777 process that calls Exim. A local part should be specified with any prefix or
2778 suffix stripped, because that is how it appears to the filter when a message is
2779 actually being delivered.
2781 .vitem &%-bfp%&&~<&'prefix'&>
2782 .oindex "&%-bfp%&"
2783 This sets the prefix of the local part of the recipient address when a filter
2784 file is being tested by means of the &%-bf%& option. The default is an empty
2785 prefix.
2787 .vitem &%-bfs%&&~<&'suffix'&>
2788 .oindex "&%-bfs%&"
2789 This sets the suffix of the local part of the recipient address when a filter
2790 file is being tested by means of the &%-bf%& option. The default is an empty
2791 suffix.
2793 .vitem &%-bh%&&~<&'IP&~address'&>
2794 .oindex "&%-bh%&"
2795 .cindex "testing" "incoming SMTP"
2796 .cindex "SMTP" "testing incoming"
2797 .cindex "testing" "relay control"
2798 .cindex "relaying" "testing configuration"
2799 .cindex "policy control" "testing"
2800 .cindex "debugging" "&%-bh%& option"
2801 This option runs a fake SMTP session as if from the given IP address, using the
2802 standard input and output. The IP address may include a port number at the end,
2803 after a full stop. For example:
2804 .code
2805 exim -bh
2806 exim -bh fe80::a00:20ff:fe86:a061.5678
2807 .endd
2808 When an IPv6 address is given, it is converted into canonical form. In the case
2809 of the second example above, the value of &$sender_host_address$& after
2810 conversion to the canonical form is
2811 &`fe80:0000:0000:0a00:20ff:fe86:a061.5678`&.
2813 Comments as to what is going on are written to the standard error file. These
2814 include lines beginning with &"LOG"& for anything that would have been logged.
2815 This facility is provided for testing configuration options for incoming
2816 messages, to make sure they implement the required policy. For example, you can
2817 test your relay controls using &%-bh%&.
2819 &*Warning 1*&:
2820 .cindex "RFC 1413"
2821 You can test features of the configuration that rely on ident (RFC 1413)
2822 information by using the &%-oMt%& option. However, Exim cannot actually perform
2823 an ident callout when testing using &%-bh%& because there is no incoming SMTP
2824 connection.
2826 &*Warning 2*&: Address verification callouts (see section &<<SECTcallver>>&)
2827 are also skipped when testing using &%-bh%&. If you want these callouts to
2828 occur, use &%-bhc%& instead.
2830 Messages supplied during the testing session are discarded, and nothing is
2831 written to any of the real log files. There may be pauses when DNS (and other)
2832 lookups are taking place, and of course these may time out. The &%-oMi%& option
2833 can be used to specify a specific IP interface and port if this is important,
2834 and &%-oMaa%& and &%-oMai%& can be used to set parameters as if the SMTP
2835 session were authenticated.
2837 The &'exim_checkaccess'& utility is a &"packaged"& version of &%-bh%& whose
2838 output just states whether a given recipient address from a given host is
2839 acceptable or not. See section &<<SECTcheckaccess>>&.
2841 Features such as authentication and encryption, where the client input is not
2842 plain text, cannot easily be tested with &%-bh%&. Instead, you should use a
2843 specialized SMTP test program such as
2844 &url(http://jetmore.org/john/code/#swaks,swaks).
2846 .vitem &%-bhc%&&~<&'IP&~address'&>
2847 .oindex "&%-bhc%&"
2848 This option operates in the same way as &%-bh%&, except that address
2849 verification callouts are performed if required. This includes consulting and
2850 updating the callout cache database.
2852 .vitem &%-bi%&
2853 .oindex "&%-bi%&"
2854 .cindex "alias file" "building"
2855 .cindex "building alias file"
2856 .cindex "Sendmail compatibility" "&%-bi%& option"
2857 Sendmail interprets the &%-bi%& option as a request to rebuild its alias file.
2858 Exim does not have the concept of a single alias file, and so it cannot mimic
2859 this behaviour. However, calls to &_/usr/lib/sendmail_& with the &%-bi%& option
2860 tend to appear in various scripts such as NIS make files, so the option must be
2861 recognized.
2863 If &%-bi%& is encountered, the command specified by the &%bi_command%&
2864 configuration option is run, under the uid and gid of the caller of Exim. If
2865 the &%-oA%& option is used, its value is passed to the command as an argument.
2866 The command set by &%bi_command%& may not contain arguments. The command can
2867 use the &'exim_dbmbuild'& utility, or some other means, to rebuild alias files
2868 if this is required. If the &%bi_command%& option is not set, calling Exim with
2869 &%-bi%& is a no-op.
2871 .vitem &%-bm%&
2872 .oindex "&%-bm%&"
2873 .cindex "local message reception"
2874 This option runs an Exim receiving process that accepts an incoming,
2875 locally-generated message on the current input. The recipients are given as the
2876 command arguments (except when &%-t%& is also present &-- see below). Each
2877 argument can be a comma-separated list of RFC 2822 addresses. This is the
2878 default option for selecting the overall action of an Exim call; it is assumed
2879 if no other conflicting option is present.
2881 If any addresses in the message are unqualified (have no domain), they are
2882 qualified by the values of the &%qualify_domain%& or &%qualify_recipient%&
2883 options, as appropriate. The &%-bnq%& option (see below) provides a way of
2884 suppressing this for special cases.
2886 Policy checks on the contents of local messages can be enforced by means of
2887 the non-SMTP ACL. See chapter &<<CHAPACL>>& for details.
2889 .cindex "return code" "for &%-bm%&"
2890 The return code is zero if the message is successfully accepted. Otherwise, the
2891 action is controlled by the &%-oe%&&'x'& option setting &-- see below.
2893 The format
2894 .cindex "message" "format"
2895 .cindex "format" "message"
2896 .cindex "&""From""& line"
2897 .cindex "UUCP" "&""From""& line"
2898 .cindex "Sendmail compatibility" "&""From""& line"
2899 of the message must be as defined in RFC 2822, except that, for
2900 compatibility with Sendmail and Smail, a line in one of the forms
2901 .code
2902 From sender Fri Jan 5 12:55 GMT 1997
2903 From sender Fri, 5 Jan 97 12:55:01
2904 .endd
2905 (with the weekday optional, and possibly with additional text after the date)
2906 is permitted to appear at the start of the message. There appears to be no
2907 authoritative specification of the format of this line. Exim recognizes it by
2908 matching against the regular expression defined by the &%uucp_from_pattern%&
2909 option, which can be changed if necessary.
2911 .oindex "&%-f%&" "overriding &""From""& line"
2912 The specified sender is treated as if it were given as the argument to the
2913 &%-f%& option, but if a &%-f%& option is also present, its argument is used in
2914 preference to the address taken from the message. The caller of Exim must be a
2915 trusted user for the sender of a message to be set in this way.
2917 .vitem &%-bnq%&
2918 .oindex "&%-bnq%&"
2919 .cindex "address qualification, suppressing"
2920 By default, Exim automatically qualifies unqualified addresses (those
2921 without domains) that appear in messages that are submitted locally (that
2922 is, not over TCP/IP). This qualification applies both to addresses in
2923 envelopes, and addresses in header lines. Sender addresses are qualified using
2924 &%qualify_domain%&, and recipient addresses using &%qualify_recipient%& (which
2925 defaults to the value of &%qualify_domain%&).
2927 Sometimes, qualification is not wanted. For example, if &%-bS%& (batch SMTP) is
2928 being used to re-submit messages that originally came from remote hosts after
2929 content scanning, you probably do not want to qualify unqualified addresses in
2930 header lines. (Such lines will be present only if you have not enabled a header
2931 syntax check in the appropriate ACL.)
2933 The &%-bnq%& option suppresses all qualification of unqualified addresses in
2934 messages that originate on the local host. When this is used, unqualified
2935 addresses in the envelope provoke errors (causing message rejection) and
2936 unqualified addresses in header lines are left alone.
2939 .vitem &%-bP%&
2940 .oindex "&%-bP%&"
2941 .cindex "configuration options" "extracting"
2942 .cindex "options" "configuration &-- extracting"
2943 If this option is given with no arguments, it causes the values of all Exim's
2944 main configuration options to be written to the standard output. The values
2945 of one or more specific options can be requested by giving their names as
2946 arguments, for example:
2947 .code
2948 exim -bP qualify_domain hold_domains
2949 .endd
2950 .cindex "hiding configuration option values"
2951 .cindex "configuration options" "hiding value of"
2952 .cindex "options" "hiding value of"
2953 However, any option setting that is preceded by the word &"hide"& in the
2954 configuration file is not shown in full, except to an admin user. For other
2955 users, the output is as in this example:
2956 .code
2957 mysql_servers = <value not displayable>
2958 .endd
2959 If &%configure_file%& is given as an argument, the name of the run time
2960 configuration file is output.
2961 If a list of configuration files was supplied, the value that is output here
2962 is the name of the file that was actually used.
2964 .cindex "daemon" "process id (pid)"
2965 .cindex "pid (process id)" "of daemon"
2966 If &%log_file_path%& or &%pid_file_path%& are given, the names of the
2967 directories where log files and daemon pid files are written are output,
2968 respectively. If these values are unset, log files are written in a
2969 sub-directory of the spool directory called &%log%&, and the pid file is
2970 written directly into the spool directory.
2972 If &%-bP%& is followed by a name preceded by &`+`&, for example,
2973 .code
2974 exim -bP +local_domains
2975 .endd
2976 it searches for a matching named list of any type (domain, host, address, or
2977 local part) and outputs what it finds.
2979 .cindex "options" "router &-- extracting"
2980 .cindex "options" "transport &-- extracting"
2981 If one of the words &%router%&, &%transport%&, or &%authenticator%& is given,
2982 followed by the name of an appropriate driver instance, the option settings for
2983 that driver are output. For example:
2984 .code
2985 exim -bP transport local_delivery
2986 .endd
2987 The generic driver options are output first, followed by the driver's private
2988 options. A list of the names of drivers of a particular type can be obtained by
2989 using one of the words &%router_list%&, &%transport_list%&, or
2990 &%authenticator_list%&, and a complete list of all drivers with their option
2991 settings can be obtained by using &%routers%&, &%transports%&, or
2992 &%authenticators%&.
2995 .vitem &%-bp%&
2996 .oindex "&%-bp%&"
2997 .cindex "queue" "listing messages on"
2998 .cindex "listing" "messages on the queue"
2999 This option requests a listing of the contents of the mail queue on the
3000 standard output. If the &%-bp%& option is followed by a list of message ids,
3001 just those messages are listed. By default, this option can be used only by an
3002 admin user. However, the &%queue_list_requires_admin%& option can be set false
3003 to allow any user to see the queue.
3005 Each message on the queue is displayed as in the following example:
3006 .code
3007 25m 2.9K 0t5C6f-0000c8-00 <alice@wonderland.fict.example>
3008 red.king@looking-glass.fict.example
3009 <other addresses>
3010 .endd
3011 .cindex "message" "size in queue listing"
3012 .cindex "size" "of message"
3013 The first line contains the length of time the message has been on the queue
3014 (in this case 25 minutes), the size of the message (2.9K), the unique local
3015 identifier for the message, and the message sender, as contained in the
3016 envelope. For bounce messages, the sender address is empty, and appears as
3017 &"<>"&. If the message was submitted locally by an untrusted user who overrode
3018 the default sender address, the user's login name is shown in parentheses
3019 before the sender address.
3021 .cindex "frozen messages" "in queue listing"
3022 If the message is frozen (attempts to deliver it are suspended) then the text
3023 &"*** frozen ***"& is displayed at the end of this line.
3025 The recipients of the message (taken from the envelope, not the headers) are
3026 displayed on subsequent lines. Those addresses to which the message has already
3027 been delivered are marked with the letter D. If an original address gets
3028 expanded into several addresses via an alias or forward file, the original is
3029 displayed with a D only when deliveries for all of its child addresses are
3030 complete.
3033 .vitem &%-bpa%&
3034 .oindex "&%-bpa%&"
3035 This option operates like &%-bp%&, but in addition it shows delivered addresses
3036 that were generated from the original top level address(es) in each message by
3037 alias or forwarding operations. These addresses are flagged with &"+D"& instead
3038 of just &"D"&.
3041 .vitem &%-bpc%&
3042 .oindex "&%-bpc%&"
3043 .cindex "queue" "count of messages on"
3044 This option counts the number of messages on the queue, and writes the total
3045 to the standard output. It is restricted to admin users, unless
3046 &%queue_list_requires_admin%& is set false.
3049 .vitem &%-bpr%&
3050 .oindex "&%-bpr%&"
3051 This option operates like &%-bp%&, but the output is not sorted into
3052 chronological order of message arrival. This can speed it up when there are
3053 lots of messages on the queue, and is particularly useful if the output is
3054 going to be post-processed in a way that doesn't need the sorting.
3056 .vitem &%-bpra%&
3057 .oindex "&%-bpra%&"
3058 This option is a combination of &%-bpr%& and &%-bpa%&.
3060 .vitem &%-bpru%&
3061 .oindex "&%-bpru%&"
3062 This option is a combination of &%-bpr%& and &%-bpu%&.
3065 .vitem &%-bpu%&
3066 .oindex "&%-bpu%&"
3067 This option operates like &%-bp%& but shows only undelivered top-level
3068 addresses for each message displayed. Addresses generated by aliasing or
3069 forwarding are not shown, unless the message was deferred after processing by a
3070 router with the &%one_time%& option set.
3073 .vitem &%-brt%&
3074 .oindex "&%-brt%&"
3075 .cindex "testing" "retry configuration"
3076 .cindex "retry" "configuration testing"
3077 This option is for testing retry rules, and it must be followed by up to three
3078 arguments. It causes Exim to look for a retry rule that matches the values
3079 and to write it to the standard output. For example:
3080 .code
3081 exim -brt bach.comp.mus.example
3082 Retry rule: *.comp.mus.example F,2h,15m; F,4d,30m;
3083 .endd
3084 See chapter &<<CHAPretry>>& for a description of Exim's retry rules. The first
3085 argument, which is required, can be a complete address in the form
3086 &'local_part@domain'&, or it can be just a domain name. If the second argument
3087 contains a dot, it is interpreted as an optional second domain name; if no
3088 retry rule is found for the first argument, the second is tried. This ties in
3089 with Exim's behaviour when looking for retry rules for remote hosts &-- if no
3090 rule is found that matches the host, one that matches the mail domain is
3091 sought. Finally, an argument that is the name of a specific delivery error, as
3092 used in setting up retry rules, can be given. For example:
3093 .code
3094 exim -brt haydn.comp.mus.example quota_3d
3095 Retry rule: *@haydn.comp.mus.example quota_3d F,1h,15m
3096 .endd
3098 .vitem &%-brw%&
3099 .oindex "&%-brw%&"
3100 .cindex "testing" "rewriting"
3101 .cindex "rewriting" "testing"
3102 This option is for testing address rewriting rules, and it must be followed by
3103 a single argument, consisting of either a local part without a domain, or a
3104 complete address with a fully qualified domain. Exim outputs how this address
3105 would be rewritten for each possible place it might appear. See chapter
3106 &<<CHAPrewrite>>& for further details.
3108 .vitem &%-bS%&
3109 .oindex "&%-bS%&"
3110 .cindex "SMTP" "batched incoming"
3111 .cindex "batched SMTP input"
3112 This option is used for batched SMTP input, which is an alternative interface
3113 for non-interactive local message submission. A number of messages can be
3114 submitted in a single run. However, despite its name, this is not really SMTP
3115 input. Exim reads each message's envelope from SMTP commands on the standard
3116 input, but generates no responses. If the caller is trusted, or
3117 &%untrusted_set_sender%& is set, the senders in the SMTP MAIL commands are
3118 believed; otherwise the sender is always the caller of Exim.
3120 The message itself is read from the standard input, in SMTP format (leading
3121 dots doubled), terminated by a line containing just a single dot. An error is
3122 provoked if the terminating dot is missing. A further message may then follow.
3124 As for other local message submissions, the contents of incoming batch SMTP
3125 messages can be checked using the non-SMTP ACL (see chapter &<<CHAPACL>>&).
3126 Unqualified addresses are automatically qualified using &%qualify_domain%& and
3127 &%qualify_recipient%&, as appropriate, unless the &%-bnq%& option is used.
3129 Some other SMTP commands are recognized in the input. HELO and EHLO act
3130 as RSET; VRFY, EXPN, ETRN, and HELP act as NOOP;
3131 QUIT quits, ignoring the rest of the standard input.
3133 .cindex "return code" "for &%-bS%&"
3134 If any error is encountered, reports are written to the standard output and
3135 error streams, and Exim gives up immediately. The return code is 0 if no error
3136 was detected; it is 1 if one or more messages were accepted before the error
3137 was detected; otherwise it is 2.
3139 More details of input using batched SMTP are given in section
3140 &<<SECTincomingbatchedSMTP>>&.
3142 .vitem &%-bs%&
3143 .oindex "&%-bs%&"
3144 .cindex "SMTP" "local input"
3145 .cindex "local SMTP input"
3146 This option causes Exim to accept one or more messages by reading SMTP commands
3147 on the standard input, and producing SMTP replies on the standard output. SMTP
3148 policy controls, as defined in ACLs (see chapter &<<CHAPACL>>&) are applied.
3149 Some user agents use this interface as a way of passing locally-generated
3150 messages to the MTA.
3152 In
3153 .cindex "sender" "source of"
3154 this usage, if the caller of Exim is trusted, or &%untrusted_set_sender%& is
3155 set, the senders of messages are taken from the SMTP MAIL commands.
3156 Otherwise the content of these commands is ignored and the sender is set up as
3157 the calling user. Unqualified addresses are automatically qualified using
3158 &%qualify_domain%& and &%qualify_recipient%&, as appropriate, unless the
3159 &%-bnq%& option is used.
3161 .cindex "inetd"
3162 The
3163 &%-bs%& option is also used to run Exim from &'inetd'&, as an alternative to
3164 using a listening daemon. Exim can distinguish the two cases by checking
3165 whether the standard input is a TCP/IP socket. When Exim is called from
3166 &'inetd'&, the source of the mail is assumed to be remote, and the comments
3167 above concerning senders and qualification do not apply. In this situation,
3168 Exim behaves in exactly the same way as it does when receiving a message via
3169 the listening daemon.
3171 .vitem &%-bt%&
3172 .oindex "&%-bt%&"
3173 .cindex "testing" "addresses"
3174 .cindex "address" "testing"
3175 This option runs Exim in address testing mode, in which each argument is taken
3176 as a recipient address to be tested for deliverability. The results are
3177 written to the standard output. If a test fails, and the caller is not an admin
3178 user, no details of the failure are output, because these might contain
3179 sensitive information such as usernames and passwords for database lookups.
3181 If no arguments are given, Exim runs in an interactive manner, prompting with a
3182 right angle bracket for addresses to be tested.
3184 Unlike the &%-be%& test option, you cannot arrange for Exim to use the
3185 &[readline()]& function, because it is running as &'root'& and there are
3186 security issues.
3188 Each address is handled as if it were the recipient address of a message
3189 (compare the &%-bv%& option). It is passed to the routers and the result is
3190 written to the standard output. However, any router that has
3191 &%no_address_test%& set is bypassed. This can make &%-bt%& easier to use for
3192 genuine routing tests if your first router passes everything to a scanner
3193 program.
3195 .cindex "return code" "for &%-bt%&"
3196 The return code is 2 if any address failed outright; it is 1 if no address
3197 failed outright but at least one could not be resolved for some reason. Return
3198 code 0 is given only when all addresses succeed.
3200 .cindex "duplicate addresses"
3201 &*Note*&: When actually delivering a message, Exim removes duplicate recipient
3202 addresses after routing is complete, so that only one delivery takes place.
3203 This does not happen when testing with &%-bt%&; the full results of routing are
3204 always shown.
3206 &*Warning*&: &%-bt%& can only do relatively simple testing. If any of the
3207 routers in the configuration makes any tests on the sender address of a
3208 message,
3209 .oindex "&%-f%&" "for address testing"
3210 you can use the &%-f%& option to set an appropriate sender when running
3211 &%-bt%& tests. Without it, the sender is assumed to be the calling user at the
3212 default qualifying domain. However, if you have set up (for example) routers
3213 whose behaviour depends on the contents of an incoming message, you cannot test
3214 those conditions using &%-bt%&. The &%-N%& option provides a possible way of
3215 doing such tests.
3217 .vitem &%-bV%&
3218 .oindex "&%-bV%&"
3219 .cindex "version number of Exim"
3220 This option causes Exim to write the current version number, compilation
3221 number, and compilation date of the &'exim'& binary to the standard output.
3222 It also lists the DBM library this is being used, the optional modules (such as
3223 specific lookup types), the drivers that are included in the binary, and the
3224 name of the run time configuration file that is in use.
3226 As part of its operation, &%-bV%& causes Exim to read and syntax check its
3227 configuration file. However, this is a static check only. It cannot check
3228 values that are to be expanded. For example, although a misspelt ACL verb is
3229 detected, an error in the verb's arguments is not. You cannot rely on &%-bV%&
3230 alone to discover (for example) all the typos in the configuration; some
3231 realistic testing is needed. The &%-bh%& and &%-N%& options provide more
3232 dynamic testing facilities.
3234 .vitem &%-bv%&
3235 .oindex "&%-bv%&"
3236 .cindex "verifying address" "using &%-bv%&"
3237 .cindex "address" "verification"
3238 This option runs Exim in address verification mode, in which each argument is
3239 taken as a recipient address to be verified by the routers. (This does
3240 not involve any verification callouts). During normal operation, verification
3241 happens mostly as a consequence processing a &%verify%& condition in an ACL
3242 (see chapter &<<CHAPACL>>&). If you want to test an entire ACL, possibly
3243 including callouts, see the &%-bh%& and &%-bhc%& options.
3245 If verification fails, and the caller is not an admin user, no details of the
3246 failure are output, because these might contain sensitive information such as
3247 usernames and passwords for database lookups.
3249 If no arguments are given, Exim runs in an interactive manner, prompting with a
3250 right angle bracket for addresses to be verified.
3252 Unlike the &%-be%& test option, you cannot arrange for Exim to use the
3253 &[readline()]& function, because it is running as &'exim'& and there are
3254 security issues.
3256 Verification differs from address testing (the &%-bt%& option) in that routers
3257 that have &%no_verify%& set are skipped, and if the address is accepted by a
3258 router that has &%fail_verify%& set, verification fails. The address is
3259 verified as a recipient if &%-bv%& is used; to test verification for a sender
3260 address, &%-bvs%& should be used.
3262 If the &%-v%& option is not set, the output consists of a single line for each
3263 address, stating whether it was verified or not, and giving a reason in the
3264 latter case. Without &%-v%&, generating more than one address by redirection
3265 causes verification to end successfully, without considering the generated
3266 addresses. However, if just one address is generated, processing continues,
3267 and the generated address must verify successfully for the overall verification
3268 to succeed.
3270 When &%-v%& is set, more details are given of how the address has been handled,
3271 and in the case of address redirection, all the generated addresses are also
3272 considered. Verification may succeed for some and fail for others.
3274 The
3275 .cindex "return code" "for &%-bv%&"
3276 return code is 2 if any address failed outright; it is 1 if no address
3277 failed outright but at least one could not be resolved for some reason. Return
3278 code 0 is given only when all addresses succeed.
3280 If any of the routers in the configuration makes any tests on the sender
3281 address of a message, you should use the &%-f%& option to set an appropriate
3282 sender when running &%-bv%& tests. Without it, the sender is assumed to be the
3283 calling user at the default qualifying domain.
3285 .vitem &%-bvs%&
3286 .oindex "&%-bvs%&"
3287 This option acts like &%-bv%&, but verifies the address as a sender rather
3288 than a recipient address. This affects any rewriting and qualification that
3289 might happen.
3291 .vitem &%-C%&&~<&'filelist'&>
3292 .oindex "&%-C%&"
3293 .cindex "configuration file" "alternate"
3294 .cindex "CONFIGURE_FILE"
3295 .cindex "alternate configuration file"
3296 This option causes Exim to find the run time configuration file from the given
3297 list instead of from the list specified by the CONFIGURE_FILE
3298 compile-time setting. Usually, the list will consist of just a single file
3299 name, but it can be a colon-separated list of names. In this case, the first
3300 file that exists is used. Failure to open an existing file stops Exim from
3301 proceeding any further along the list, and an error is generated.
3303 When this option is used by a caller other than root or the Exim user, and the
3304 list is different from the compiled-in list, Exim gives up its root privilege
3305 immediately, and runs with the real and effective uid and gid set to those of
3306 the caller. However, if ALT_CONFIG_ROOT_ONLY is defined in
3307 &_Local/Makefile_&, root privilege is retained for &%-C%& only if the caller of
3308 Exim is root.
3310 That is, the Exim user is no longer privileged in this regard. This build-time
3311 option is not set by default in the Exim source distribution tarbundle.
3312 However, if you are using a &"packaged"& version of Exim (source or binary),
3313 the packagers might have enabled it.
3315 Setting ALT_CONFIG_ROOT_ONLY locks out the possibility of testing a
3316 configuration using &%-C%& right through message reception and delivery, even
3317 if the caller is root. The reception works, but by that time, Exim is running
3318 as the Exim user, so when it re-executes to regain privilege for the delivery,
3319 the use of &%-C%& causes privilege to be lost. However, root can test reception
3320 and delivery using two separate commands (one to put a message on the queue,
3321 using &%-odq%&, and another to do the delivery, using &%-M%&).
3323 If ALT_CONFIG_PREFIX is defined &_in Local/Makefile_&, it specifies a
3324 prefix string with which any file named in a &%-C%& command line option
3325 must start. In addition, the file name must not contain the sequence &`/../`&.
3326 However, if the value of the &%-C%& option is identical to the value of
3327 CONFIGURE_FILE in &_Local/Makefile_&, Exim ignores &%-C%& and proceeds as
3328 usual. There is no default setting for ALT_CONFIG_PREFIX; when it is
3329 unset, any file name can be used with &%-C%&.
3331 ALT_CONFIG_PREFIX can be used to confine alternative configuration files
3332 to a directory to which only root has access. This prevents someone who has
3333 broken into the Exim account from running a privileged Exim with an arbitrary
3334 configuration file.
3336 The &%-C%& facility is useful for ensuring that configuration files are
3337 syntactically correct, but cannot be used for test deliveries, unless the
3338 caller is privileged, or unless it is an exotic configuration that does not
3339 require privilege. No check is made on the owner or group of the files
3340 specified by this option.
3342 .vitem &%-D%&<&'macro'&>=<&'value'&>
3343 .oindex "&%-D%&"
3344 .cindex "macro" "setting on command line"
3345 This option can be used to override macro definitions in the configuration file
3346 (see section &<<SECTmacrodefs>>&). However, like &%-C%&, if it is used by an
3347 unprivileged caller, it causes Exim to give up its root privilege.
3348 If DISABLE_D_OPTION is defined in &_Local/Makefile_&, the use of &%-D%& is
3349 completely disabled, and its use causes an immediate error exit.
3351 The entire option (including equals sign if present) must all be within one
3352 command line item. &%-D%& can be used to set the value of a macro to the empty
3353 string, in which case the equals sign is optional. These two commands are
3354 synonymous:
3355 .code
3356 exim -DABC ...
3357 exim -DABC= ...
3358 .endd
3359 To include spaces in a macro definition item, quotes must be used. If you use
3360 quotes, spaces are permitted around the macro name and the equals sign. For
3361 example:
3362 .code
3363 exim '-D ABC = something' ...
3364 .endd
3365 &%-D%& may be repeated up to 10 times on a command line.
3367 .vitem &%-d%&<&'debug&~options'&>
3368 .oindex "&%-d%&"
3369 .cindex "debugging" "list of selectors"
3370 .cindex "debugging" "&%-d%& option"
3371 This option causes debugging information to be written to the standard
3372 error stream. It is restricted to admin users because debugging output may show
3373 database queries that contain password information. Also, the details of users'
3374 filter files should be protected. If a non-admin user uses &%-d%&, Exim
3375 writes an error message to the standard error stream and exits with a non-zero
3376 return code.
3378 When &%-d%& is used, &%-v%& is assumed. If &%-d%& is given on its own, a lot of
3379 standard debugging data is output. This can be reduced, or increased to include
3380 some more rarely needed information, by directly following &%-d%& with a string
3381 made up of names preceded by plus or minus characters. These add or remove sets
3382 of debugging data, respectively. For example, &%-d+filter%& adds filter
3383 debugging, whereas &%-d-all+filter%& selects only filter debugging. Note that
3384 no spaces are allowed in the debug setting. The available debugging categories
3385 are:
3386 .display
3387 &`acl `& ACL interpretation
3388 &`auth `& authenticators
3389 &`deliver `& general delivery logic
3390 &`dns `& DNS lookups (see also resolver)
3391 &`dnsbl `& DNS black list (aka RBL) code
3392 &`exec `& arguments for &[execv()]& calls
3393 &`expand `& detailed debugging for string expansions
3394 &`filter `& filter handling
3395 &`hints_lookup `& hints data lookups
3396 &`host_lookup `& all types of name-to-IP address handling
3397 &`ident `& ident lookup
3398 &`interface `& lists of local interfaces
3399 &`lists `& matching things in lists
3400 &`load `& system load checks
3401 &`local_scan `& can be used by &[local_scan()]& (see chapter &&&
3402 &<<CHAPlocalscan>>&)
3403 &`lookup `& general lookup code and all lookups
3404 &`memory `& memory handling
3405 &`pid `& add pid to debug output lines
3406 &`process_info `& setting info for the process log
3407 &`queue_run `& queue runs
3408 &`receive `& general message reception logic
3409 &`resolver `& turn on the DNS resolver's debugging output
3410 &`retry `& retry handling
3411 &`rewrite `& address rewriting
3412 &`route `& address routing
3413 &`timestamp `& add timestamp to debug output lines
3414 &`tls `& TLS logic
3415 &`transport `& transports
3416 &`uid `& changes of uid/gid and looking up uid/gid
3417 &`verify `& address verification logic
3418 &`all `& almost all of the above (see below), and also &%-v%&
3419 .endd
3420 The &`all`& option excludes &`memory`& when used as &`+all`&, but includes it
3421 for &`-all`&. The reason for this is that &`+all`& is something that people
3422 tend to use when generating debug output for Exim maintainers. If &`+memory`&
3423 is included, an awful lot of output that is very rarely of interest is
3424 generated, so it now has to be explicitly requested. However, &`-all`& does
3425 turn everything off.
3427 .cindex "resolver, debugging output"
3428 .cindex "DNS resolver, debugging output"
3429 The &`resolver`& option produces output only if the DNS resolver was compiled
3430 with DEBUG enabled. This is not the case in some operating systems. Also,
3431 unfortunately, debugging output from the DNS resolver is written to stdout
3432 rather than stderr.
3434 The default (&%-d%& with no argument) omits &`expand`&, &`filter`&,
3435 &`interface`&, &`load`&, &`memory`&, &`pid`&, &`resolver`&, and &`timestamp`&.
3436 However, the &`pid`& selector is forced when debugging is turned on for a
3437 daemon, which then passes it on to any re-executed Exims. Exim also
3438 automatically adds the pid to debug lines when several remote deliveries are
3439 run in parallel.
3441 The &`timestamp`& selector causes the current time to be inserted at the start
3442 of all debug output lines. This can be useful when trying to track down delays
3443 in processing.
3445 If the &%debug_print%& option is set in any driver, it produces output whenever
3446 any debugging is selected, or if &%-v%& is used.
3448 .vitem &%-dd%&<&'debug&~options'&>
3449 .oindex "&%-dd%&"
3450 This option behaves exactly like &%-d%& except when used on a command that
3451 starts a daemon process. In that case, debugging is turned off for the
3452 subprocesses that the daemon creates. Thus, it is useful for monitoring the
3453 behaviour of the daemon without creating as much output as full debugging does.
3455 .vitem &%-dropcr%&
3456 .oindex "&%-dropcr%&"
3457 This is an obsolete option that is now a no-op. It used to affect the way Exim
3458 handled CR and LF characters in incoming messages. What happens now is
3459 described in section &<<SECTlineendings>>&.
3461 .vitem &%-E%&
3462 .oindex "&%-E%&"
3463 .cindex "bounce message" "generating"
3464 This option specifies that an incoming message is a locally-generated delivery
3465 failure report. It is used internally by Exim when handling delivery failures
3466 and is not intended for external use. Its only effect is to stop Exim
3467 generating certain messages to the postmaster, as otherwise message cascades
3468 could occur in some situations. As part of the same option, a message id may
3469 follow the characters &%-E%&. If it does, the log entry for the receipt of the
3470 new message contains the id, following &"R="&, as a cross-reference.
3472 .vitem &%-e%&&'x'&
3473 .oindex "&%-e%&&'x'&"
3474 There are a number of Sendmail options starting with &%-oe%& which seem to be
3475 called by various programs without the leading &%o%& in the option. For
3476 example, the &%vacation%& program uses &%-eq%&. Exim treats all options of the
3477 form &%-e%&&'x'& as synonymous with the corresponding &%-oe%&&'x'& options.
3479 .vitem &%-F%&&~<&'string'&>
3480 .oindex "&%-F%&"
3481 .cindex "sender" "name"
3482 .cindex "name" "of sender"
3483 This option sets the sender's full name for use when a locally-generated
3484 message is being accepted. In the absence of this option, the user's &'gecos'&
3485 entry from the password data is used. As users are generally permitted to alter
3486 their &'gecos'& entries, no security considerations are involved. White space
3487 between &%-F%& and the <&'string'&> is optional.
3489 .vitem &%-f%&&~<&'address'&>
3490 .oindex "&%-f%&"
3491 .cindex "sender" "address"
3492 .cindex "address" "sender"
3493 .cindex "trusted users"
3494 .cindex "envelope sender"
3495 .cindex "user" "trusted"
3496 This option sets the address of the envelope sender of a locally-generated
3497 message (also known as the return path). The option can normally be used only
3498 by a trusted user, but &%untrusted_set_sender%& can be set to allow untrusted
3499 users to use it.
3501 Processes running as root or the Exim user are always trusted. Other
3502 trusted users are defined by the &%trusted_users%& or &%trusted_groups%&
3503 options. In the absence of &%-f%&, or if the caller is not trusted, the sender
3504 of a local message is set to the caller's login name at the default qualify
3505 domain.
3507 There is one exception to the restriction on the use of &%-f%&: an empty sender
3508 can be specified by any user, trusted or not, to create a message that can
3509 never provoke a bounce. An empty sender can be specified either as an empty
3510 string, or as a pair of angle brackets with nothing between them, as in these
3511 examples of shell commands:
3512 .code
3513 exim -f '<>' user@domain
3514 exim -f "" user@domain
3515 .endd
3516 In addition, the use of &%-f%& is not restricted when testing a filter file
3517 with &%-bf%& or when testing or verifying addresses using the &%-bt%& or
3518 &%-bv%& options.
3520 Allowing untrusted users to change the sender address does not of itself make
3521 it possible to send anonymous mail. Exim still checks that the &'From:'& header
3522 refers to the local user, and if it does not, it adds a &'Sender:'& header,
3523 though this can be overridden by setting &%no_local_from_check%&.
3525 White
3526 .cindex "&""From""& line"
3527 space between &%-f%& and the <&'address'&> is optional (that is, they can be
3528 given as two arguments or one combined argument). The sender of a
3529 locally-generated message can also be set (when permitted) by an initial
3530 &"From&~"& line in the message &-- see the description of &%-bm%& above &-- but
3531 if &%-f%& is also present, it overrides &"From&~"&.
3533 .vitem &%-G%&
3534 .oindex "&%-G%&"
3535 .cindex "Sendmail compatibility" "&%-G%& option ignored"
3536 This is a Sendmail option which is ignored by Exim.
3538 .vitem &%-h%&&~<&'number'&>
3539 .oindex "&%-h%&"
3540 .cindex "Sendmail compatibility" "&%-h%& option ignored"
3541 This option is accepted for compatibility with Sendmail, but has no effect. (In
3542 Sendmail it overrides the &"hop count"& obtained by counting &'Received:'&
3543 headers.)
3545 .vitem &%-i%&
3546 .oindex "&%-i%&"
3547 .cindex "Solaris" "&'mail'& command"
3548 .cindex "dot" "in incoming non-SMTP message"
3549 This option, which has the same effect as &%-oi%&, specifies that a dot on a
3550 line by itself should not terminate an incoming, non-SMTP message. I can find
3551 no documentation for this option in Solaris 2.4 Sendmail, but the &'mailx'&
3552 command in Solaris 2.4 uses it. See also &%-ti%&.
3554 .vitem &%-M%&&~<&'message&~id'&>&~<&'message&~id'&>&~...
3555 .oindex "&%-M%&"
3556 .cindex "forcing delivery"
3557 .cindex "delivery" "forcing attempt"
3558 .cindex "frozen messages" "forcing delivery"
3559 This option requests Exim to run a delivery attempt on each message in turn. If
3560 any of the messages are frozen, they are automatically thawed before the
3561 delivery attempt. The settings of &%queue_domains%&, &%queue_smtp_domains%&,
3562 and &%hold_domains%& are ignored.
3564 Retry
3565 .cindex "hints database" "overriding retry hints"
3566 hints for any of the addresses are overridden &-- Exim tries to deliver even if
3567 the normal retry time has not yet been reached. This option requires the caller
3568 to be an admin user. However, there is an option called &%prod_requires_admin%&
3569 which can be set false to relax this restriction (and also the same requirement
3570 for the &%-q%&, &%-R%&, and &%-S%& options).
3572 The deliveries happen synchronously, that is, the original Exim process does
3573 not terminate until all the delivery attempts have finished. No output is
3574 produced unless there is a serious error. If you want to see what is happening,
3575 use the &%-v%& option as well, or inspect Exim's main log.
3577 .vitem &%-Mar%&&~<&'message&~id'&>&~<&'address'&>&~<&'address'&>&~...
3578 .oindex "&%-Mar%&"
3579 .cindex "message" "adding recipients"
3580 .cindex "recipient" "adding"
3581 This option requests Exim to add the addresses to the list of recipients of the
3582 message (&"ar"& for &"add recipients"&). The first argument must be a message
3583 id, and the remaining ones must be email addresses. However, if the message is
3584 active (in the middle of a delivery attempt), it is not altered. This option
3585 can be used only by an admin user.
3587 .vitem "&%-MC%&&~<&'transport'&>&~<&'hostname'&>&~<&'sequence&~number'&>&&&
3588 &~<&'message&~id'&>"
3589 .oindex "&%-MC%&"
3590 .cindex "SMTP" "passed connection"
3591 .cindex "SMTP" "multiple deliveries"
3592 .cindex "multiple SMTP deliveries"
3593 This option is not intended for use by external callers. It is used internally
3594 by Exim to invoke another instance of itself to deliver a waiting message using
3595 an existing SMTP connection, which is passed as the standard input. Details are
3596 given in chapter &<<CHAPSMTP>>&. This must be the final option, and the caller
3597 must be root or the Exim user in order to use it.
3599 .vitem &%-MCA%&
3600 .oindex "&%-MCA%&"
3601 This option is not intended for use by external callers. It is used internally
3602 by Exim in conjunction with the &%-MC%& option. It signifies that the
3603 connection to the remote host has been authenticated.
3605 .vitem &%-MCP%&
3606 .oindex "&%-MCP%&"
3607 This option is not intended for use by external callers. It is used internally
3608 by Exim in conjunction with the &%-MC%& option. It signifies that the server to
3609 which Exim is connected supports pipelining.
3611 .vitem &%-MCQ%&&~<&'process&~id'&>&~<&'pipe&~fd'&>
3612 .oindex "&%-MCQ%&"
3613 This option is not intended for use by external callers. It is used internally
3614 by Exim in conjunction with the &%-MC%& option when the original delivery was
3615 started by a queue runner. It passes on the process id of the queue runner,
3616 together with the file descriptor number of an open pipe. Closure of the pipe
3617 signals the final completion of the sequence of processes that are passing
3618 messages through the same SMTP connection.
3620 .vitem &%-MCS%&
3621 .oindex "&%-MCS%&"
3622 This option is not intended for use by external callers. It is used internally
3623 by Exim in conjunction with the &%-MC%& option, and passes on the fact that the
3624 SMTP SIZE option should be used on messages delivered down the existing
3625 connection.
3627 .vitem &%-MCT%&
3628 .oindex "&%-MCT%&"
3629 This option is not intended for use by external callers. It is used internally
3630 by Exim in conjunction with the &%-MC%& option, and passes on the fact that the
3631 host to which Exim is connected supports TLS encryption.
3633 .vitem &%-Mc%&&~<&'message&~id'&>&~<&'message&~id'&>&~...
3634 .oindex "&%-Mc%&"
3635 .cindex "hints database" "not overridden by &%-Mc%&"
3636 .cindex "delivery" "manually started &-- not forced"
3637 This option requests Exim to run a delivery attempt on each message in turn,
3638 but unlike the &%-M%& option, it does check for retry hints, and respects any
3639 that are found. This option is not very useful to external callers. It is
3640 provided mainly for internal use by Exim when it needs to re-invoke itself in
3641 order to regain root privilege for a delivery (see chapter &<<CHAPsecurity>>&).
3642 However, &%-Mc%& can be useful when testing, in order to run a delivery that
3643 respects retry times and other options such as &%hold_domains%& that are
3644 overridden when &%-M%& is used. Such a delivery does not count as a queue run.
3645 If you want to run a specific delivery as if in a queue run, you should use
3646 &%-q%& with a message id argument. A distinction between queue run deliveries
3647 and other deliveries is made in one or two places.
3649 .vitem &%-Mes%&&~<&'message&~id'&>&~<&'address'&>
3650 .oindex "&%-Mes%&"
3651 .cindex "message" "changing sender"
3652 .cindex "sender" "changing"
3653 This option requests Exim to change the sender address in the message to the
3654 given address, which must be a fully qualified address or &"<>"& (&"es"& for
3655 &"edit sender"&). There must be exactly two arguments. The first argument must
3656 be a message id, and the second one an email address. However, if the message
3657 is active (in the middle of a delivery attempt), its status is not altered.
3658 This option can be used only by an admin user.
3660 .vitem &%-Mf%&&~<&'message&~id'&>&~<&'message&~id'&>&~...
3661 .oindex "&%-Mf%&"
3662 .cindex "freezing messages"
3663 .cindex "message" "manually freezing"
3664 This option requests Exim to mark each listed message as &"frozen"&. This
3665 prevents any delivery attempts taking place until the message is &"thawed"&,
3666 either manually or as a result of the &%auto_thaw%& configuration option.
3667 However, if any of the messages are active (in the middle of a delivery
3668 attempt), their status is not altered. This option can be used only by an admin
3669 user.
3671 .vitem &%-Mg%&&~<&'message&~id'&>&~<&'message&~id'&>&~...
3672 .oindex "&%-Mg%&"
3673 .cindex "giving up on messages"
3674 .cindex "message" "abandoning delivery attempts"
3675 .cindex "delivery" "abandoning further attempts"
3676 This option requests Exim to give up trying to deliver the listed messages,
3677 including any that are frozen. However, if any of the messages are active,
3678 their status is not altered. For non-bounce messages, a delivery error message
3679 is sent to the sender, containing the text &"cancelled by administrator"&.
3680 Bounce messages are just discarded. This option can be used only by an admin
3681 user.
3683 .vitem &%-Mmad%&&~<&'message&~id'&>&~<&'message&~id'&>&~...
3684 .oindex "&%-Mmad%&"
3685 .cindex "delivery" "cancelling all"
3686 This option requests Exim to mark all the recipient addresses in the messages
3687 as already delivered (&"mad"& for &"mark all delivered"&). However, if any
3688 message is active (in the middle of a delivery attempt), its status is not
3689 altered. This option can be used only by an admin user.
3691 .vitem &%-Mmd%&&~<&'message&~id'&>&~<&'address'&>&~<&'address'&>&~...
3692 .oindex "&%-Mmd%&"
3693 .cindex "delivery" "cancelling by address"
3694 .cindex "recipient" "removing"
3695 .cindex "removing recipients"
3696 This option requests Exim to mark the given addresses as already delivered
3697 (&"md"& for &"mark delivered"&). The first argument must be a message id, and
3698 the remaining ones must be email addresses. These are matched to recipient
3699 addresses in the message in a case-sensitive manner. If the message is active
3700 (in the middle of a delivery attempt), its status is not altered. This option
3701 can be used only by an admin user.
3703 .vitem &%-Mrm%&&~<&'message&~id'&>&~<&'message&~id'&>&~...
3704 .oindex "&%-Mrm%&"
3705 .cindex "removing messages"
3706 .cindex "abandoning mail"
3707 .cindex "message" "manually discarding"
3708 This option requests Exim to remove the given messages from the queue. No
3709 bounce messages are sent; each message is simply forgotten. However, if any of
3710 the messages are active, their status is not altered. This option can be used
3711 only by an admin user or by the user who originally caused the message to be
3712 placed on the queue.
3714 .vitem &%-Mset%&&~<&'message&~id'&>
3715 .oindex "&%-Mset%&
3716 .cindex "testing" "string expansion"
3717 .cindex "expansion" "testing"
3718 This option is useful only in conjunction with &%-be%& (that is, when testing
3719 string expansions). Exim loads the given message from its spool before doing
3720 the test expansions, thus setting message-specific variables such as
3721 &$message_size$& and the header variables. The &$recipients$& variable is made
3722 available. This feature is provided to make it easier to test expansions that
3723 make use of these variables. However, this option can be used only by an admin
3724 user. See also &%-bem%&.
3726 .vitem &%-Mt%&&~<&'message&~id'&>&~<&'message&~id'&>&~...
3727 .oindex "&%-Mt%&"
3728 .cindex "thawing messages"
3729 .cindex "unfreezing messages"
3730 .cindex "frozen messages" "thawing"
3731 .cindex "message" "thawing frozen"
3732 This option requests Exim to &"thaw"& any of the listed messages that are
3733 &"frozen"&, so that delivery attempts can resume. However, if any of the
3734 messages are active, their status is not altered. This option can be used only
3735 by an admin user.
3737 .vitem &%-Mvb%&&~<&'message&~id'&>
3738 .oindex "&%-Mvb%&"
3739 .cindex "listing" "message body"
3740 .cindex "message" "listing body of"
3741 This option causes the contents of the message body (-D) spool file to be
3742 written to the standard output. This option can be used only by an admin user.
3744 .vitem &%-Mvc%&&~<&'message&~id'&>
3745 .oindex "&%-Mvc%&"
3746 .cindex "message" "listing in RFC 2822 format"
3747 .cindex "listing" "message in RFC 2922 format"
3748 This option causes a copy of the complete message (header lines plus body) to
3749 be written to the standard output in RFC 2822 format. This option can be used
3750 only by an admin user.
3752 .vitem &%-Mvh%&&~<&'message&~id'&>
3753 .oindex "&%-Mvh%&"
3754 .cindex "listing" "message headers"
3755 .cindex "header lines" "listing"
3756 .cindex "message" "listing header lines"
3757 This option causes the contents of the message headers (-H) spool file to be
3758 written to the standard output. This option can be used only by an admin user.
3760 .vitem &%-Mvl%&&~<&'message&~id'&>
3761 .oindex "&%-Mvl%&"
3762 .cindex "listing" "message log"
3763 .cindex "message" "listing message log"
3764 This option causes the contents of the message log spool file to be written to
3765 the standard output. This option can be used only by an admin user.
3767 .vitem &%-m%&
3768 .oindex "&%-m%&"
3769 This is apparently a synonym for &%-om%& that is accepted by Sendmail, so Exim
3770 treats it that way too.
3772 .vitem &%-N%&
3773 .oindex "&%-N%&"
3774 .cindex "debugging" "&%-N%& option"
3775 .cindex "debugging" "suppressing delivery"
3776 This is a debugging option that inhibits delivery of a message at the transport
3777 level. It implies &%-v%&. Exim goes through many of the motions of delivery &--
3778 it just doesn't actually transport the message, but instead behaves as if it
3779 had successfully done so. However, it does not make any updates to the retry
3780 database, and the log entries for deliveries are flagged with &"*>"& rather
3781 than &"=>"&.
3783 Because &%-N%& discards any message to which it applies, only root or the Exim
3784 user are allowed to use it with &%-bd%&, &%-q%&, &%-R%& or &%-M%&. In other
3785 words, an ordinary user can use it only when supplying an incoming message to
3786 which it will apply. Although transportation never fails when &%-N%& is set, an
3787 address may be deferred because of a configuration problem on a transport, or a
3788 routing problem. Once &%-N%& has been used for a delivery attempt, it sticks to
3789 the message, and applies to any subsequent delivery attempts that may happen
3790 for that message.
3792 .vitem &%-n%&
3793 .oindex "&%-n%&"
3794 .cindex "Sendmail compatibility" "&%-n%& option ignored"
3795 This option is interpreted by Sendmail to mean &"no aliasing"&. It is ignored
3796 by Exim.
3798 .vitem &%-O%&&~<&'data'&>
3799 .oindex "&%-O%&"
3800 This option is interpreted by Sendmail to mean &`set option`&. It is ignored by
3801 Exim.
3803 .vitem &%-oA%&&~<&'file&~name'&>
3804 .oindex "&%-oA%&"
3805 .cindex "Sendmail compatibility" "&%-oA%& option"
3806 This option is used by Sendmail in conjunction with &%-bi%& to specify an
3807 alternative alias file name. Exim handles &%-bi%& differently; see the
3808 description above.
3810 .vitem &%-oB%&&~<&'n'&>
3811 .oindex "&%-oB%&"
3812 .cindex "SMTP" "passed connection"
3813 .cindex "SMTP" "multiple deliveries"
3814 .cindex "multiple SMTP deliveries"
3815 This is a debugging option which limits the maximum number of messages that can
3816 be delivered down one SMTP connection, overriding the value set in any &(smtp)&
3817 transport. If <&'n'&> is omitted, the limit is set to 1.
3819 .vitem &%-odb%&
3820 .oindex "&%-odb%&"
3821 .cindex "background delivery"
3822 .cindex "delivery" "in the background"
3823 This option applies to all modes in which Exim accepts incoming messages,
3824 including the listening daemon. It requests &"background"& delivery of such
3825 messages, which means that the accepting process automatically starts a
3826 delivery process for each message received, but does not wait for the delivery
3827 processes to finish.
3829 When all the messages have been received, the reception process exits,
3830 leaving the delivery processes to finish in their own time. The standard output
3831 and error streams are closed at the start of each delivery process.
3832 This is the default action if none of the &%-od%& options are present.
3834 If one of the queueing options in the configuration file
3835 (&%queue_only%& or &%queue_only_file%&, for example) is in effect, &%-odb%&
3836 overrides it if &%queue_only_override%& is set true, which is the default
3837 setting. If &%queue_only_override%& is set false, &%-odb%& has no effect.
3839 .vitem &%-odf%&
3840 .oindex "&%-odf%&"
3841 .cindex "foreground delivery"
3842 .cindex "delivery" "in the foreground"
3843 This option requests &"foreground"& (synchronous) delivery when Exim has
3844 accepted a locally-generated message. (For the daemon it is exactly the same as
3845 &%-odb%&.) A delivery process is automatically started to deliver the message,
3846 and Exim waits for it to complete before proceeding.
3848 The original Exim reception process does not finish until the delivery
3849 process for the final message has ended. The standard error stream is left open
3850 during deliveries.
3852 However, like &%-odb%&, this option has no effect if &%queue_only_override%& is
3853 false and one of the queueing options in the configuration file is in effect.
3855 If there is a temporary delivery error during foreground delivery, the
3856 message is left on the queue for later delivery, and the original reception
3857 process exits. See chapter &<<CHAPnonqueueing>>& for a way of setting up a
3858 restricted configuration that never queues messages.
3861 .vitem &%-odi%&
3862 .oindex "&%-odi%&"
3863 This option is synonymous with &%-odf%&. It is provided for compatibility with
3864 Sendmail.
3866 .vitem &%-odq%&
3867 .oindex "&%-odq%&"
3868 .cindex "non-immediate delivery"
3869 .cindex "delivery" "suppressing immediate"
3870 .cindex "queueing incoming messages"
3871 This option applies to all modes in which Exim accepts incoming messages,
3872 including the listening daemon. It specifies that the accepting process should
3873 not automatically start a delivery process for each message received. Messages
3874 are placed on the queue, and remain there until a subsequent queue runner
3875 process encounters them. There are several configuration options (such as
3876 &%queue_only%&) that can be used to queue incoming messages under certain
3877 conditions. This option overrides all of them and also &%-odqs%&. It always
3878 forces queueing.
3880 .vitem &%-odqs%&
3881 .oindex "&%-odqs%&"
3882 .cindex "SMTP" "delaying delivery"
3883 This option is a hybrid between &%-odb%&/&%-odi%& and &%-odq%&.
3884 However, like &%-odb%& and &%-odi%&, this option has no effect if
3885 &%queue_only_override%& is false and one of the queueing options in the
3886 configuration file is in effect.
3888 When &%-odqs%& does operate, a delivery process is started for each incoming
3889 message, in the background by default, but in the foreground if &%-odi%& is
3890 also present. The recipient addresses are routed, and local deliveries are done
3891 in the normal way. However, if any SMTP deliveries are required, they are not
3892 done at this time, so the message remains on the queue until a subsequent queue
3893 runner process encounters it. Because routing was done, Exim knows which
3894 messages are waiting for which hosts, and so a number of messages for the same
3895 host can be sent in a single SMTP connection. The &%queue_smtp_domains%&
3896 configuration option has the same effect for specific domains. See also the
3897 &%-qq%& option.
3899 .vitem &%-oee%&
3900 .oindex "&%-oee%&"
3901 .cindex "error" "reporting"
3902 If an error is detected while a non-SMTP message is being received (for
3903 example, a malformed address), the error is reported to the sender in a mail
3904 message.
3906 .cindex "return code" "for &%-oee%&"
3907 Provided
3908 this error message is successfully sent, the Exim receiving process
3909 exits with a return code of zero. If not, the return code is 2 if the problem
3910 is that the original message has no recipients, or 1 any other error. This is
3911 the default &%-oe%&&'x'& option if Exim is called as &'rmail'&.
3913 .vitem &%-oem%&
3914 .oindex "&%-oem%&"
3915 .cindex "error" "reporting"
3916 .cindex "return code" "for &%-oem%&"
3917 This is the same as &%-oee%&, except that Exim always exits with a non-zero
3918 return code, whether or not the error message was successfully sent.
3919 This is the default &%-oe%&&'x'& option, unless Exim is called as &'rmail'&.
3921 .vitem &%-oep%&
3922 .oindex "&%-oep%&"
3923 .cindex "error" "reporting"
3924 If an error is detected while a non-SMTP message is being received, the
3925 error is reported by writing a message to the standard error file (stderr).
3926 .cindex "return code" "for &%-oep%&"
3927 The return code is 1 for all errors.
3929 .vitem &%-oeq%&
3930 .oindex "&%-oeq%&"
3931 .cindex "error" "reporting"
3932 This option is supported for compatibility with Sendmail, but has the same
3933 effect as &%-oep%&.
3935 .vitem &%-oew%&
3936 .oindex "&%-oew%&"
3937 .cindex "error" "reporting"
3938 This option is supported for compatibility with Sendmail, but has the same
3939 effect as &%-oem%&.
3941 .vitem &%-oi%&
3942 .oindex "&%-oi%&"
3943 .cindex "dot" "in incoming non-SMTP message"
3944 This option, which has the same effect as &%-i%&, specifies that a dot on a
3945 line by itself should not terminate an incoming, non-SMTP message. Otherwise, a
3946 single dot does terminate, though Exim does no special processing for other
3947 lines that start with a dot. This option is set by default if Exim is called as
3948 &'rmail'&. See also &%-ti%&.
3950 .vitem &%-oitrue%&
3951 .oindex "&%-oitrue%&"
3952 This option is treated as synonymous with &%-oi%&.
3954 .vitem &%-oMa%&&~<&'host&~address'&>
3955 .oindex "&%-oMa%&"
3956 .cindex "sender" "host address, specifying for local message"
3957 A number of options starting with &%-oM%& can be used to set values associated
3958 with remote hosts on locally-submitted messages (that is, messages not received
3959 over TCP/IP). These options can be used by any caller in conjunction with the
3960 &%-bh%&, &%-be%&, &%-bf%&, &%-bF%&, &%-bt%&, or &%-bv%& testing options. In
3961 other circumstances, they are ignored unless the caller is trusted.
3963 The &%-oMa%& option sets the sender host address. This may include a port
3964 number at the end, after a full stop (period). For example:
3965 .code
3966 exim -bs -oMa
3967 .endd
3968 An alternative syntax is to enclose the IP address in square brackets,
3969 followed by a colon and the port number:
3970 .code
3971 exim -bs -oMa []:1234
3972 .endd
3973 The IP address is placed in the &$sender_host_address$& variable, and the
3974 port, if present, in &$sender_host_port$&. If both &%-oMa%& and &%-bh%&
3975 are present on the command line, the sender host IP address is taken from
3976 whichever one is last.
3978 .vitem &%-oMaa%&&~<&'name'&>
3979 .oindex "&%-oMaa%&"
3980 .cindex "authentication" "name, specifying for local message"
3981 See &%-oMa%& above for general remarks about the &%-oM%& options. The &%-oMaa%&
3982 option sets the value of &$sender_host_authenticated$& (the authenticator
3983 name). See chapter &<<CHAPSMTPAUTH>>& for a discussion of SMTP authentication.
3984 This option can be used with &%-bh%& and &%-bs%& to set up an
3985 authenticated SMTP session without actually using the SMTP AUTH command.
3987 .vitem &%-oMai%&&~<&'string'&>
3988 .oindex "&%-oMai%&"
3989 .cindex "authentication" "id, specifying for local message"
3990 See &%-oMa%& above for general remarks about the &%-oM%& options. The &%-oMai%&
3991 option sets the value of &$authenticated_id$& (the id that was authenticated).
3992 This overrides the default value (the caller's login id, except with &%-bh%&,
3993 where there is no default) for messages from local sources. See chapter
3994 &<<CHAPSMTPAUTH>>& for a discussion of authenticated ids.
3996 .vitem &%-oMas%&&~<&'address'&>
3997 .oindex "&%-oMas%&"
3998 .cindex "authentication" "sender, specifying for local message"
3999 See &%-oMa%& above for general remarks about the &%-oM%& options. The &%-oMas%&
4000 option sets the authenticated sender value in &$authenticated_sender$&. It