Remove broken code in exim.h that tried to preserve EX_OK when it was
[exim.git] / doc / doc-txt / Exim3.upgrade
1$Cambridge: exim/doc/doc-txt/Exim3.upgrade,v 1.1 2004/10/07 15:04:35 ph10 Exp $
3This document contains information about upgrading Exim to the last of the 3.xx
4releases. It is provided to help anybody who is upgrading to release 4.xx from
5a release that is earlier than 3.33. It goes back as far as release 2.12. If
6you are upgrading to release 4.xx from an even earlier release, it is probably
7best to start again from the default configuration.
10Upgrading from release 3.16
131. The way LDAP returns values for multiple attributes has been changed to be
14the same as the NIS+ lookup.
16If you specify multiple attributes, they are returned as space-separated
17strings, quoted if necessary.
19e.g. ldap:///o=base?attr1,attr2?sub?(uid=fred)
21 used to give: attr1=value one, attr2=value2
22 now gives: attr1="value one" attr2=value2
24If you don't specify any attributes in the search, you now get them in
25the tagged format as well.
27e.g. ldap:///o=base??sub?(uid=fred)
29 used to give: top, value one, value2
30 now gives: objectClass=top attr1="value one" attr2=value2
32The reason for these changes is so that the results can be safely parsed -
33in fact, the existing ${extract{key}{val}} function does this nicely.
34This in turn allows a single LDAP query to be reused - one query can return
35the destination delivery address, the quota, and so forth.
37This is NOT a backwards compatible change, so there is a compile-time option
38to reverse it in the src/lookups/ldap.c module, for use in emergency. But it is
39not thought that the old behaviour was particularly useful as it stood, because
40a field that contained ',' or '=' would make the result unparseable.
42In the common case where you explicitly ask for a single attribute in your
43LDAP query, the behaviour is unchanged - the result is not quoted, and if there
44are multiple values they are comma-separated.
462. The hosts_max_try option in the smtp transport limits the number of IP
47addresses that will actually be tried during one delivery attempt. The default
48is 5. Previously, all available addresses were tried.
503. The extension of the "extract" expansion item has resulted in a change to
51the way Exim decides between the keyed form and the numeric form. If the first
52argument consists entirely of digits, the numeric form is assumed. This means
53that it is impossible to have keys that are digit strings, without manipulating
54the data first (e.g. by using ${sg} to add a letter to each key).
57Upgrading from release 3.15
601. The handling of "freeze" and "fail" in system filter files has changed.
61Previously, any deliveries set up by a filter that ended with "freeze" or
62"fail" were discarded. This no longer happens; such deliveries are honoured.
63A consequence of this is that first_delivery becomes false after freezing in a
64system filter; previously it remained true until a real delivery attempt
68Upgrading from release 3.13
711. The handling of maildir_tag has been changed (see NewStuff). There are two
72small incompatibilities: (a) Exim now inserts a leading colon only if the
73string begins with an alphanumeric character. So if you were using a string
74starting with a special character, you will have to add the leading colon to
75it to remain compatible. (b) The expansion of maildir_tag now happens after the
76file has been written, and $message_size is updated to the correct file size
77before the expansion. The tag is not used on the temporary file (it was
802. The handling of Exim's configuration has changed in two ways:
82 (a) Any line may be continued by ending it with a backslash. Trailing white
83 space after the backslash, and leading white space on continuation lines is
84 ignored. This means that quotes are no longer needed just to make it possible
85 to continue an option setting. The difference between quoted and non-quoted
86 strings is that quoted strings are processed for internal backslashed items
87 such as \n. The only possible incompatibility of this change is if any
88 existing configuration has a non-quoted line ended in backslash, which seems
89 a very remote possibility.
91 (b) All lists, with the exception of log_file_path, can now use a different
92 character to colon as the separator. This is specified by starting the list
93 with <x where x is any punctuation character. For example:
95 local_interfaces = <; ; ::1
97 The new feature is provided to make life easier with IPv6 addresses. It is
98 recommended that its use be confined to circumstances where it really is
99 needed, and that colon be used in most cases. I don't believe this change
100 is incompatible, because I don't think any list item can legitimately begin
101 with a '<' character.
1033. Previously, Exim took no action to ensure that the timestamps in its log
104files were "wall clock time". If the TZ environment variable was set when Exim
105was called, it could cause strange times to be logged. For the majority of
106operating systems, I have been able to fix this problem by deleting the entire
107environment. However, this doesn't work in some systems, and a macro called
108HANDS_OFF_ENVIRONMENT is defined in their OS/os.h files to suppress the action.
109These OS are: AIX, DGUX, HP-UX, IRIX, and SCO, and their behaviour should be
110unchanged from previous releases. On any other OS, if you find you are getting
111weird timestamps, it may be that your OS needs HANDS_OFF_ENVIRONMENT.
1134. As a result of the change described in 3, there may be some cases where Exim
114runs an external program that previously got passed the environment, and now do
115not. This does *not* apply to the pipe transport, where the environment has
116always been set up specifically, as described in the manual.
1185. The way in which Exim scans its queue when split_spool_directory is set has
119changed, but this shouldn't make any noticeable difference. See doc/NewStuff
120for defails.
123Upgrading from release 3.03
126The from_hack option in the appendfile and pipe transports has been replace by
127two string options, check_string and escape_string. If your configuration
128contains any references to from_hack they should be replaced. Exim continues to
129recognize from_hack as a transitional measure. If no_from_hack is specified in
130an appendfile transport, the two new options are forced to be unset. Otherwise
131the setting of from_hack is ignored.
134Upgrading from release 3.02
137The exim_dbmbuild utility has been changed to write a warning to stderr on
138encountering a duplicate key, and to return a value of 1. Formerly, it ignored
139all but the last of a set of duplicates; now it ignores all but the first, to
140make dbm-searched files behave the same way as lsearch-searched files. However,
141there is an option -lastdup which makes it behave as before. The -nowarn option
142suppresses the individual warnings, but the number of duplicates is always
143listed on stdout at the end.
146Updating from a release prior to 3.00
149Prior to release 3.00 a lot of options which contained lists of various kinds
150came in groups such as sender_accept, sender_reject, sender_reject_except. This
151style of configuration has been abolished. Instead, it is now possible to put
152negative entries in such lists, so that a single option is all that is
153required. In addition to this, net lists have been abolished, and instead,
154host lists can now contain items that specify networks as well as hosts. The
155names of some of these options have also been changed.
157As a result of these changes, most configuration files used for earlier
158versions of Exim need to be changed. The opportunity has therefore been taken
159to remove a number of other obsolete features and options.
161A Perl script is built in the file util/convert4r3 to assist in updating Exim
162configuration files. It reads a configuration file on the standard input,
163writes a modified file on the standard output, and writes comments about what
164it has done to the standard error file. It assumes that the input is a valid
165Exim configuration file. A typical call to the conversion script might be
167 util/convert4r3 </opt/exim/configure >/opt/exim/
169The way the script merges an accept/reject/reject_except triple into a single
170accept option is to put the reject_except list first, followed by the reject
171list with every item negated, followed by the accept list. For example, if an
172old configuration file contains
174 sender_host_accept_relay = *.c.d : e.f.g
175 sender_host_reject_relay = *.b.c.d
176 sender_host_reject_relay_except = a.b.c.d
178the new configuration will contain
180 host_accept_relay = a.b.c.d : ! *.b.c.d : *.c.d : e.f.g
182The same ordering is used to merge a triple into a reject option, but this time
183the first and third sublists are negated. For example, if an old configuration
184file contains
186 sender_host_accept = *.c.d : e.f.g
187 sender_host_reject = *.b.c.d
188 sender_host_reject_except = a.b.c.d
190the new configuration file will contain
192 host_reject = ! a.b.c.d : *.b.c.d : ! *.c.d : ! e.f.g : *
194The output file should be checked before trying to use it. Each option change
195is preceded by an identifying comment. There are several specific things that
196you should look out for when checking:
198(1) If you are using macros to contain lists of items, and these have to be
199 negated in the new world, convert4r3 won't get it right. For example, if
200 the old configuration contains
202 ACCEPTHOSTS = *.c.d : e.f.g
203 sender_host_reject = ACCEPTHOSTS
205 then the rewritten configuration will be
207 ACCEPTHOSTS = *.c.d : e.f.g
208 host_reject = !ACCEPTHOSTS
210 but because this is just textual macro handling, that is equivalent to
212 host_reject = !*.c.d : e.f.g
214 which is not the correct translation, because the second item is not
215 negated. There is unfortunately no easy way to use a macro to provide a
216 list of things that are sometimes negated.
218(2) The conversion adds some settings of file_transport, pipe_transport, and
219 reply_transport to aliasfile and forwardfile directors. This is done
220 because the global implicit defaults for these options have been removed.
221 The default configuration now contains explicit settings, so convert4r3
222 makes these additions to be compatible with that. If your aliasfile and
223 forwardfile directors do not make use of the pipe, file, or autoreply
224 facilities, you can remove these new settings.
226(3) If you are using +allow_unknown in a host list which also has an exception
227 list, you may need to move +allow_unknown in the new configuration. For
228 example, if the old configuration contains
230 sender_host_reject = +allow_unknown : *.b.c
231 sender_host_reject_except = *.a.b.c
233 then the rewritten configuration will be
235 host_reject = ! *.a.b.c : +allow_unknown : *.b.c
237 Because the negated item contains a wild card, the reverse lookup for the
238 host name will occur before +allow_unknown is encountered, and therefore
239 +allow_unknown will have no effect. It should be moved to the start of the
240 list.
242One way of upgrading Exim from a pre-3.00 release to a post-3.00 release is as
2451. Suppose your configuration file is called /opt/exim/configure, and you want
246 to continue with this name after upgrading. The first thing to do is to make
247 another copy of this file called, say, /opt/exim/configure.pre-3.00.
2492. Rebuild your existing Exim to use the copy of the configuration file instead
250 of the standard file. Install this version of Exim under a special name such
251 as exim-2.12, and point a symbolic link called "exim" at it. Then HUP your
252 daemon. You can check on the name of the configuration file by running
254 exim -bP configure_file
256 Ensure that everything is running smoothly.
2583. Build the new release, configured to use the standard configuration file.
2604. Use the convert4r3 utility to upgrade your configuration file for the new
261 release. After running it, check the file by hand.
2635. If any of the options that convert4r3 rewrote contained regular expressions
264 that had backslashes in them, and were not previously in quotes, they will
265 need modification if convert4r3 has put them into quotes. Either re-arrange
266 the option to remove the quoting, or escape each backslash. For example, if
267 you had
269 sender_reject_recipients = ^\d{8}@
270 sender_reject_except = ^\d{8}@x.y.z
272 convert4r3 will have combined the two settings into
274 sender_reject_recipients = "! ^\d{8}@x.y.z : \
275 ^\d{8}@"
277 This must be changed to
279 sender_reject_recipients = ! ^\d{8}@x.y.z : ^\d{8}@
280 or
281 sender_reject_recipients = "! ^\\d{8}@x.y.z : ^\\d{8}@"
283 In the second case, the quoted string could of course still be split
284 over several lines.
2866. If your configuration refers to any external lists of networks, check them
287 to ensure that all the masks are in the single-number form, because Exim no
288 longer recognizes the dotted quad form of mask. For example, if an item in
289 a netlist file is
293 you must change it to
297 Otherwise Exim will not recognize it as a masked IP address, and will treat
298 it as a host name. The convert4r3 utility makes this conversion for networks
299 that are mentioned inline in the configuration, but it does not handle
300 referenced files.
3027. Check the newly-built Exim as much as possible without installing; you can,
303 for example, use a command such as
305 ./exim -bV
307 in the build directory to test that it successfully reads the new
308 configuration file. You can also do tests using -bt and -bh.
3108. Install the new release under a special name such as exim-3.00.
3129. You can then easily change between the new and old releases simply by moving
313 the symbolic link and HUPping your daemon.
316Details of syntax changes at 3.00
3191. A bare file name without a preceding search type may appear in a domain
320list; this causes each line of the file to be read and processed as if it were
321an item in the list, except that it cannot itself be a bare file name (that is,
322this facility cannot be used recursively). Wild cards and regular expressions
323may be used in the lines of the file just as in the main list.
324For example, if
326 local_domains = /etc/local-domains
328then the file could contain lines like
330 *
332This is different to an lsearch file, which operates like any other lookup type
333and does an exact search for the key. If a # character appears anywhere in a
334line of the file, it and all following characters are ignored. Blank lines are
335also ignored.
3372. Any item in a domain list (including a bare file name) can be preceded by an
338exclamation mark character, to indicate negation. White space after the ! is
339ignored. If the domain matches the rest of the item, it is *not* in the set of
340domains that the option is defining. If the end of the list is reached, the
341domain is accepted if the last item was a negative one, but not if it was a
342positive one. If ! precedes a bare file name, then all items in the file are
343negated, unless they are preceded by another exclamation mark. For example:
345 relay_domains = !a.b.c : *.b.c
347sets up a.b.c as an exception to the more general item *.b.c, because lists are
348processed from left to right. If the domain that is being checked matches
349neither a.b.c nor *.b.c, then it is not accepted as a relay domain, because the
350last item in the list is a positive item. However, if the option were just
352 relay_domains = !a.b.c
354then all domains other than a.b.c would be relay domains, because the last item
355in the list is a negative item. In effect, a list that ends with a negative
356item has ": *" appended to it.
3583. Negation and bare file names are available as above in lists of local parts
359(e.g. in local_parts options) and complete addresses (address lists). For the
360special "@@" lookup form in address lists, negation also can be used in the
361list of local parts that is looked up for the domain. For example, with
363 sender_reject_recipients = @@dbm;/etc/reject-by-domain
365the file could contain lines like this:
367 !postmaster : !hostmaster : *
369If a local part that actually begins with ! is required, it has to be specified
370using a regular expression. Because local parts may legitimately contain #
371characters, a comment in the file is recognized only if # is followed by white
372space or the end of the line.
3744. Host lists may now contain network items, as in the former net list options,
375which have all been abolished. The only form of network masking is the /n
376variety. Negation and bare file names can appear in host lists, and there is a
377new type of item which allows masked network numbers to be used as keys in
378lookups, thus making it possible to used DBM files for faster checking when the
379list of networks is large.
381The complete list of types of item which can now appear in a host list is:
383. An item may be a bare file name; each line of the file may take the form of
384 any of the items below, but it may not itself be another bare file name. If
385 the file name is preceded by ! then all items in the file are negated, unless
386 they are preceded by another exclamation mark. Comments in the file are
387 introduced by # and blank lines are ignored.
389. If the entire item is "*" it matches any host.
391. If the item is in the form of an IP address, it is matched against the IP
392 address of the incoming call.
394. If the item is in the form of an IP address followed by a slash and a mask
395 length (e.g. then it is matched against the IP address of the
396 incoming call, subject to the mask.
398. If the item is of the form "net<number>-<search-type>;<search-data>", for
399 example:
401 net24-dbm;/networks.db
403 then the IP address of the incoming call is masked using <number> as the mask
404 length; a textual string is then constructed from the masked value, followed
405 by the mask, and this is then used as the key for the lookup. For example, if
406 the incoming IP address is then the key that is looked up for
407 the above example is "".
409. If the entire item is "@" the primary host name is used as the the match
410 item, and the following applies:
412. If the item is a plain domain name, then a forward DNS lookup is done on that
413 name to find its IP address(es), and the result is compared with the IP
414 address of the incoming call.
416The remaining items require the host name to be obtained by a reverse DNS
417lookup. If the lookup fails, Exim takes a hard line by default and access is
418not permitted. If the list is an "accept" list, Exim behaves as if the current
419host is not in the set defined by the list, whereas if it is a "reject" list,
420it behaves as if it is.
422To change this behaviour, the special item "+allow_unknown" may appear in the
423list (at top level - it is not recognized in an indirected file); if any
424subsequent items require a host name, and the reverse DNS lookup fails, Exim
425permits the access, that is, its behaviour is the opposite to the default.
427. If the item starts with "*" then the remainder of the item must match the end
428 of the host name. For example, *.b.c matches all hosts whose names end in
429 .b.c. This special simple form is provided because this is a very common
430 requirement. Other kinds of wildcarding require the use of a regular
431 expression.
433. If the item starts with "^" then it is taken to be a regular expression which
434 is matched against the host name. For example, ^(a|b)\.c\.d$ matches either
435 of the two hosts a.c.d or b.c.d. If the option string in which this occurs is
436 given in quotes, then the backslash characters must be doubled, because they
437 are significant in quoted strings. The following two settings are exactly
438 equivalent:
440 host_accept = ^(a|b)\.c\.d$
441 host_accept = "^(a|b)\\.c\\.d$"
443. If the item is of the form <search-type>;<filename or query>, for example
445 dbm;/host/accept/list
447 then the host name is looked up using the search type and file name or query
448 (as appropriate). The actual data that is looked up is not used.
4505. Early versions of Exim required commas and semicolons to terminate option
451settings in drivers. This hasn't been the case for quite some time. The code to
452handle them has now been removed.
455Details of option changes at 3.00
458Main options
461 * address_directory_transport, address_directory2_transport,
462 address_file_transport, address_pipe_transport, and address_reply_transport
463 have been abolished as obsolete. The aliasfile and forwardfile directors
464 have been able for some time to set the transports they want to use for
465 these special kinds of delivery; there seems little need for global
466 defaults. The default configuration has been altered to add settings for
467 file_transport and pipe_transport to the aliasfile and forwardfile
468 directors, and to add reply_transport to forwardfile.
470 * check_dns_names, a deprecated synonym for dns_check_names, has been
471 abolished.
473 * helo_accept_junk_nets is abolished; nets can now appear in
474 helo_accept_junk_hosts.
476 * helo_verify_except_hosts and helo_verify_except_nets have been abolished,
477 and helo_verify has been changed from a boolean to a host list, listing
478 those hosts for which HELO verification is required.
480 * the obsolete option helo_verify_nets (a synonym for host_lookup_nets) has
481 been abolished. Note that host_lookup_nets itself has been replaced by
482 host_lookup.
484 * hold_domains_except has been abolished. Use negated items in hold_domains.
486 * host_lookup_nets has been replaced by host_lookup, which can contain hosts
487 and nets.
489 * ignore_fromline_nets has been replaced by ignore_fromline_hosts.
491 * If message_filter is set and the filter generates any deliveries to files,
492 pipes, or any autoreplies, then the appropriate message_filter_*_transport
493 options must be set to define the transports, following the abolition of
494 the global defaults (see above).
496 * queue_remote and queue_remote_except have been abolished and replaced by
497 queue_remote_domains, which lists those domains that should be queued. The
498 effect of queue_remote=true is now obtained by queue_remote_domains=*.
500 * queue_smtp and queue_smtp_except have been abolished and replaced by
501 queue_smtp_domains, which lists those domains that should be queued after
502 routing. The effect of queue_smtp=true is now obtained by
503 queue_smtp_domains=*.
505 * rbl_except_nets has been abolished and replaced by rbl_hosts, which can
506 contain hosts and nets. This defaults to "*" and defines the set of hosts
507 for which RBL checking is done.
509 * receiver_unqualified_nets is abolished; nets can now appear in
510 receiver_unqualified_hosts.
512 * receiver_verify_except_hosts and receiver_verify_except_nets have been
513 abolished and replaced by receiver_verify_hosts, which defaults to "*".
514 This is used, however, only when receiver_verify is set - together with the
515 other conditions (receiver_verify_addresses, receiver_verify_senders).
517 * receiver_verify_senders_except has been abolished; the functionality is now
518 available by using negation in receiver_verify_senders.
520 * rfc1413_except_hosts and rfc1413_except_nets have been abolished, and
521 replaced by rfc1413_hosts, which defaults to "*".
523 * sender_accept, sender_accept_recipients and sender_reject_except have
524 been abolished; the functionality is now available via sender_reject and
525 sender_reject_recipients.
527 * sender_host_accept, sender_net_accept, sender_host_reject,
528 sender_net_reject, sender_host_reject_except, sender_net_reject_except,
529 sender_host_reject_recipients and sender_net_reject_recipients
530 have all been abolished, and replaced by the options host_reject and
531 host_reject_recipients.
533 * sender_host_accept_relay, sender_net_accept_relay,
534 sender_host_reject_relay, sender_host_reject_relay_except,
535 sender_net_reject_relay, and sender_net_reject_relay_except are abolished,
536 and replaced by host_accept_relay. This defaults unset, and this means that
537 all relaying is now by default locked out in the Exim binary. Previously,
538 if no relaying options were set, relaying was permitted.
540 * sender_unqualified_nets has been abolished; nets can now appear in
541 sender_unqualified_hosts.
543 * sender_verify_except_hosts and sender_verify_except_nets have been
544 abolished and replaced by sender_verify_hosts, which defaults to "*". This
545 is used, however, only when sender_verify is set (to make it similar to
546 receiver_verify, even though there aren't at present any other conditions.)
548 * sender_verify_log_details has been abolished. This was a little-used
549 debugging option.
551 * smtp_etrn_nets has been abolished; nets can now appear in smtp_etrn_hosts.
553 * smtp_expn_nets has been abolished; nets can now appear in smtp_expn_hosts.
555 * smtp_log_connections, a deprecated synonym for log_smtp_connections, has
556 been abolished.
558 * smtp_reserve_nets is abolished; nets can now appear in smtp_reserve_hosts.
560Generic director and router options
563 * except_domains, except_local_parts, and except_senders have been abolished.
564 Use negated items in domains, local_parts, and senders instead, for
565 example, replace
567 except_domains = a.b.c
569 with
571 domains = !a.b.c
573 If you already have a domains setting, add any negative items to the front
574 of it.
576The aliasfile director
579 * The option "directory", an obsolete synonym for home_directory, has been
580 abolished.
582The forwardfile director
585 * The option "directory", an obsolete synonym for file_directory, has been
586 abolished.
588 * The option forbid_filter_log, an obsolete synonym for
589 forbid_filter_logwrite, has been abolished.
591The localuser director
594 * The option "directory", an obsolete synonym for match_directory, has been
595 abolished.
597The lookuphost router
600 * mx_domains_except and its obsolete old name non_mx_domains have been
601 abolished. Use negated items in mx_domains.
603The pipe transport
606 * The option "directory", an obsolete synonym for home_directory, has been
607 abolished.
609The smtp transport
612 * mx_domains_except and its obsolete old name non_mx_domains have been
613 abolished. Use negated items in mx_domains.
615 * serialize_nets has been abolished; nets may now appear in serialize_hosts.
618Other items relevant to upgrading from Exim 2.12
6211. RFC 2505 (Anti-Spam Recommendations for SMTP MTAs) recommends that the
622checking of addresses for spam blocks should be done entirely caselessly.
623Previously, although Exim retained the case of the local part, in accordance
624with the RFC 821 rule that local parts are case sensitive, some of the string
625comparisons were nevertheless done caselessly, but file lookups used the
626unmodified address.
628The way addresses are compared with options whose values are address lists has
629been changed. At the start of the comparison, both the local part and the
630domain are now forced to lower case, and any comparisons that are done with
631in-line strings are done caselessly. For example,
633 sender_reject = A@b.c
635rejects both A@b.c and a@b.c. Any lookups that occur use lowercased strings as
636their keys. If the @@ lookup facility is used, the lookup is done on the lower
637cased domain name, but any subsequent string comparisons on local parts are
638done caselessly.
640To retain possibility of caseful matching, the pseudo-item "+caseful" can
641appear in an address list. It causes any subsequent items to do caseful matches
642on local parts. The domain, however, remains lower cased.
6442. The handling of incoming batched SMTP has been re-worked so as to behave in
645a more useful way in cases of error:
647 (i) The option sender_verify_batch now defaults false.
648 (ii) EOF is no longer interpreted as end-of-message; the "." line must be
649 present.
650 (iii) Exim stops immediately in cases of error, writing information to stdout
651 and stderr, and setting the return code to 1 if some messages have been
652 accepted, and 2 otherwise.
6543. The first message delivered by -R, and all messages delivered by -Rf and -qf
655are "forced" in the sense that retry information is over-ridden. Previously,
656Exim also forcibly thawed any of these messages that was frozen. This no longer
657happens. Additional options -Rff and -qff have been implemented to force
658thawing as well as delivery.
6604. When recipients are being rejected because the sending host is in an RBL
661list, Exim used just to show the RBL text, if any, as part of the rejection
662response. Now, if prohibition_message is set, it expands that string instead,
663with the RBL message available in $rbl_text, and $prohibition_reason set to
6665. When a trusted caller passed a message to Exim, it used to check the From:
667header against the caller's login (even though the caller was trusted) unless
668the -f option had been used to supply a different sender. This has been changed
669so that From: is never checked if the caller is trusted.
671Philip Hazel
672May 1999