gnutls_require_protocols comment on 4.77 notes.
[exim.git] / src / README.UPDATING
CommitLineData
0f4f2a88
PH
1This document contains detailed information about incompatibilities that might
2be encountered when upgrading from one release of Exim to another. The
3information is in reverse order of release numbers. Mostly these are relatively
4small points, and the configuration file is normally upwards compatible, but
5there have been two big upheavals...
6
7
8**************************************************************************
9* There was a big reworking of the way mail routing works for release *
10* 4.00. Previously used "directors" were abolished, and all routing is *
11* now done by routers. Policy controls for incoming mail are now done by *
12* Access Control Lists instead of separate options. All this means that *
13* pre-4.00 configuration files have to be massively converted. If you *
14* are coming from a 3.xx release, please read the document in the file *
15* doc/Exim4.upgrade, and allow some time to complete the upgrade. *
16* *
17* There was a big reworking of the way domain/host/net/address lists are *
18* handled at release 3.00. If you are coming from a pre-3.00 release, it *
19* might be easier to start again from a default configuration. Otherwise *
20* you need to read doc/Exim3.upgrade and do a double conversion of your *
21* configuration file. *
22**************************************************************************
23
24
25The rest of this document contains information about changes in 4.xx releases
26that might affect a running system.
2eda48c6 27
e6acf885 28
83e2f8a2 29Exim version 4.80
dec5017e
PP
30-----------------
31
83e2f8a2
PP
32 * BEWARE backwards-incompatible changes in SSL libraries, thus the version
33 bump. See points below for details.
34
dec5017e
PP
35 * The value of $tls_peerdn is now print-escaped when written to the spool file
36 in a -tls_peerdn line, and unescaped when read back in. We received reports
37 of values with embedded newlines, which caused spool file corruption.
38
39 If you have a corrupt spool file and you wish to recover the contents after
40 upgrading, then lock the message, replace the new-lines that should be part
41 of the -tls_peerdn line with the two-character sequence \n and then unlock
42 the message. No tool has been provided as we believe this is a rare
43 occurence.
44
c80c5570
PP
45 * With OpenSSL 1.0.1+, Exim now supports TLS 1.1 and TLS 1.2. If built
46 against 1.0.1a then you will get a warning message and the
47 "openssl_options" value will not parse "no_tlsv1_1": the value changes
48 incompatibly between 1.0.1a and 1.0.1b, because the value chosen for 1.0.1a
49 is infelicitous. We advise avoiding 1.0.1a.
50
51 "openssl_options" gains "no_tlsv1_1", "no_tlsv1_2" and "no_compression".
52
da3ad30d
PP
53 COMPATIBILITY WARNING: The default value of "openssl_options" is no longer
54 "+dont_insert_empty_fragments". We default to unset. That old default was
55 grandfathered in from before openssl_options became a configuration option.
56 Empty fragments are inserted by default through TLS1.0, to partially defend
57 against certain attacks; TLS1.1+ change the protocol so that this is not
58 needed. The DIEF SSL option was required for some old releases of mail
59 clients which did not gracefully handle the empty fragments, and was
60 initially set in Exim release 4.31 (see ChangeLog, item 37).
61
62 If you still have affected mail-clients, and you see SSL protocol failures
63 with this release of Exim, set:
64 openssl_options = +dont_insert_empty_fragments
65 in the main section of your Exim configuration file. You're trading off
66 security for compatibility. Exim is now defaulting to higher security and
67 rewarding more modern clients.
68
5407bfff
JH
69 * Ldap lookups returning multi-valued attributes now separate the attributes
70 with only a comma, not a comma-space sequence. Also, an actual comma within
71 a returned attribute is doubled. This makes it possible to parse the
72 attribute as a comma-separated list. Note the distinction from multiple
73 attributes being returned, where each one is a name=value pair.
c80c5570 74
9cbad13b
PP
75 * accept_8bitmime now defaults on, which is not RFC compliant but is better
76 suited to today's Internet. See http://cr.yp.to/smtp/8bitmime.html for a
77 sane rationale. Those who wish to be strictly RFC compliant, or know that
78 they need to talk to servers that are not 8-bit-clean, now need to take
79 explicit configuration action to default this option off. This is not a
80 new option, you can safely force it off before upgrading, to decouple
81 configuration changes from the binary upgrade while remaining RFC compliant.
82
17c76198
PP
83 * The GnuTLS support has been mostly rewritten, to use 2.12.x APIs. As part
84 of this, these three options are no longer supported:
85
86 gnutls_require_kx
87 gnutls_require_mac
88 gnutls_require_protocols
89
90 Their functionality is entirely subsumed into tls_require_ciphers, which is
91 no longer parsed apart by Exim but is instead given to
92 gnutls_priority_init(3), which is no longer an Exim list. See:
93
94 http://www.gnu.org/software/gnutls/manual/html_node/Priority-Strings.html
95
96 for fuller documentation of the strings parsed. The three gnutls_require_*
97 options are still parsed by Exim and, for this release, silently ignored.
98 A future release will add warnings, before a later still release removes
99 parsing entirely and the presence of the options will be a configuration
100 error.
101
83e2f8a2
PP
102 Note that by default, GnuTLS will not accept RSA-MD5 signatures in chains.
103 A tls_require_ciphers value of NORMAL:%VERIFY_ALLOW_SIGN_RSA_MD5 may
104 re-enable support, but this is not supported by the Exim maintainers.
105 Our test suite no longer includes MD5-based certificates.
106
17c76198
PP
107 This rewrite means that Exim will continue to build against GnuTLS in the
108 future, brings Exim closer to other GnuTLS applications and lets us add
109 support for SNI and other features more readily. We regret that it wasn't
110 feasible to retain the three dropped options.
111
dec5017e 112
c566dd90
PP
113Exim version 4.77
114-----------------
115
116 * GnuTLS will now attempt to use TLS 1.2 and TLS 1.1 before TLS 1.0 and SSL3,
117 if supported by your GnuTLS library. Use the existing
118 "gnutls_require_protocols" option to downgrade this if that will be a
119 problem. Prior to this release, supported values were "TLS1" and "SSL3",
120 so you should be able to update configuration prior to update.
121
0215ec07
PP
122 [nb: gnutls_require_protocols removed in Exim 4.80, instead use
123 tls_require_ciphers to provide a priority string; see notes above]
124
39257585
PP
125 * The match_<type>{string1}{string2} expansion conditions no longer subject
126 string2 to string expansion, unless Exim was built with the new
127 "EXPAND_LISTMATCH_RHS" option. Too many people have inadvertently created
128 insecure configurations that way. If you need the functionality and turn on
129 that build option, please let the developers know, and know why, so we can
130 try to provide a safer mechanism for you.
131
a7ee5955
PP
132 The match{}{} expansion condition (for regular expressions) is NOT affected.
133 For match_<type>{s1}{s2}, all list functionality is unchanged. The only
134 change is that a '$' appearing in s2 will not trigger expansion, but instead
135 will be treated as a literal $ sign; the effect is very similar to having
136 wrapped s2 with \N...\N. If s2 contains a named list and the list definition
137 uses $expansions then those _will_ be processed as normal. It is only the
138 point at which s2 is read where expansion is inhibited.
139
140 If you are trying to test if two email addresses are equal, use eqi{s1}{s2}.
141 If you are testing if the address in s1 occurs in the list of items given
142 in s2, either use the new inlisti{s1}{s2} condition (added in 4.77) or use
143 the pre-existing forany{s2}{eqi{$item}{s1}} condition.
144
c566dd90 145
e6acf885
PP
146Exim version 4.74
147-----------------
148
4050a044
PP
149 * The integrated support for dynamically loadable lookup modules has an ABI
150 change from the modules supported by some OS vendors through an unofficial
151 patch. Don't try to mix & match.
152
153 * Some parts of the build system are now beginning to assume that the host
154 environment is POSIX. If you're building on a system where POSIX tools are
155 not the default, you might have an easier time if you switch to the POSIX
156 tools. Feel free to report non-POSIX issues as a request for a feature
157 enhancement, but if the POSIX variants are available then the fix will
158 probably just involve some coercion. See the README instructions for
159 building on such hosts.
e6acf885
PP
160
161
162Exim version 4.73
163-----------------
164
165 * The Exim run-time user can no longer be root; this was always
166 strongly discouraged, but is now prohibited both at build and
167 run-time. If you need Exim to run routinely as root, you'll need to
168 patch the source and accept the risk. Here be dragons.
169
170 * Exim will no longer accept a configuration file owned by the Exim
171 run-time user, unless that account is explicitly the value in
172 CONFIGURE_OWNER, which we discourage. Exim now checks to ensure that
a7ee5955 173 files are not writeable by other accounts.
e6acf885
PP
174
175 * The ALT_CONFIG_ROOT_ONLY build option is no longer optional and is forced
176 on; the Exim user can, by default, no longer use -C/-D and retain privilege.
177 Two new build options mitigate this.
178
179 * TRUSTED_CONFIG_LIST defines a file containing a whitelist of config
180 files that are trusted to be selected by the Exim user; one per line.
181 This is the recommended approach going forward.
182
183 * WHITELIST_D_MACROS defines a colon-separated list of macro names which
184 the Exim run-time user may safely pass without dropping privileges.
185 Because changes to this involve a recompile, this is not the recommended
186 approach but may ease transition. The values of the macros, when
43236f35 187 overridden, are constrained to match this regex: ^[A-Za-z0-9_/.-]*$
e6acf885
PP
188
189 * The system_filter_user option now defaults to the Exim run-time user,
190 rather than root. You can still set it explicitly to root and this
191 can be done with prior versions too, letting you roll versions
192 without needing to change this configuration option.
193
194 * ClamAV must be at least version 0.95 unless WITH_OLD_CLAMAV_STREAM is
195 defined at build time.
196
197
2eda48c6
TK
198Exim version 4.70
199-----------------
200
2011. Experimental Yahoo! Domainkeys support has been dropped in this release.
202It has been superceded by a native implementation of its successor DKIM.
203
2042. Up to version 4.69, Exim came with an embedded version of the PCRE library.
205As of 4.70, this is no longer the case. To compile Exim, you will need PCRE
a7ee5955 206installed. Most OS distributions have ready-made library and development
2eda48c6 207packages.
0f4f2a88
PH
208
209
3c223874
PH
210Exim version 4.68
211-----------------
212
2131. The internal implementation of the database keys that are used for ACL
214ratelimiting has been tidied up. This means that an update to 4.68 might cause
215Exim to "forget" previous rates that it had calculated, and reset them to zero.
216
217
26da7e20
PH
218Exim version 4.64
219-----------------
220
2211. Callouts were setting the name used for EHLO/HELO from $smtp_active_
222hostname. This is wrong, because it relates to the incoming message (and
223probably the interface on which it is arriving) and not to the outgoing
224callout (which could be using a different interface). This has been
225changed to use the value of the helo_data option from the smtp transport
226instead - this is what is used when a message is actually being sent. If
227there is no remote transport (possible with a router that sets up host
228addresses), $smtp_active_hostname is used. This change is mentioned here in
229case somebody is relying on the use of $smtp_active_hostname.
230
ebc9d865
PH
2312. A bug has been fixed that might just possibly be something that is relied on
232in some configurations. In expansion items such as ${if >{xxx}{yyy}...} an
233empty string (that is {}) was being interpreted as if it was {0} and therefore
234treated as the number zero. From release 4.64, such strings cause an error
235because a decimal number, possibly followed by K or M, is required (as has
236always been documented).
237
b6c27e28
PH
2383. There has been a change to the GnuTLS support (ChangeLog/PH/20) to improve
239Exim's performance. Unfortunately, this has the side effect of being slightly
240non-upwards compatible for versions 4.50 and earlier. If you are upgrading from
241one of these earlier versions and you use GnuTLS, you must remove the file
242called gnutls-params in Exim's spool directory. If you don't do this, you will
243see this error:
244
245 TLS error on connection from ... (DH params import): Base64 decoding error.
246
247Removing the file causes Exim to recompute the relevant encryption parameters
248and cache them in the new format that was introduced for release 4.51 (May
2492005). If you are upgrading from release 4.51 or later, there should be no
250problem.
251
26da7e20 252
a5bd321b
PH
253Exim version 4.63
254-----------------
255
256When an SMTP error message is specified in a "message" modifier in an ACL, or
257in a :fail: or :defer: message in a redirect router, Exim now checks the start
258of the message for an SMTP error code. This consists of three digits followed
259by a space, optionally followed by an extended code of the form n.n.n, also
260followed by a space. If this is the case and the very first digit is the same
261as the default error code, the code from the message is used instead. If the
262very first digit is incorrect, a panic error is logged, and the default code is
263used. This is an incompatible change, but it is not expected to affect many (if
264any) configurations. It is possible to suppress the use of the supplied code in
265a redirect router by setting the smtp_error_code option false. In this case,
266any SMTP code is quietly ignored.
267
268
47ca6d6c
PH
269Exim version 4.61
270-----------------
271
8def5aaf
PH
2721. The default number of ACL variables of each type has been increased to 20,
273and it's possible to compile Exim with more. You can safely upgrade to this
274release if you already have messages on the queue with saved ACL variable
275values. However, if you downgrade from this release with messages on the queue,
276any saved ACL values they may have will be lost.
277
2782. The default value for rfc1413_query_timeout has been changed from 30s to 5s.
47ca6d6c
PH
279
280
8857ccfd
PH
281Exim version 4.54
282-----------------
283
284There was a problem with 4.52/TF/02 in that a "name=" option on control=
285submission terminated at the next slash, thereby not allowing for slashes in
286the name. This has been changed so that "name=" takes the rest of the string as
287its data. It must therefore be the last option.
288
289
f3f0a1f0
PH
290Version 4.53
291------------
292
293If you are using the experimental Domain Keys support, you must upgrade to
294at least libdomainkeys 0.67 in order to run this release of Exim.
295
296
b5aea5e1
PH
297Version 4.51
298------------
299
c688b954
PH
3001. The format in which GnuTLS parameters are cached (in the file gnutls-params
301in the spool directory) has been changed. The new format can also be generated
b5aea5e1
PH
302externally, so it is now possible to update the values from outside Exim. This
303has been implemented in an upwards, BUT NOT downwards, compatible manner.
304Upgrading should be seamless: when Exim finds that it cannot understand an
305existing cache file, it generates new parameters and writes them to the cache
306in the new format. If, however, you downgrade from 4.51 to a previous release,
307you MUST delete the gnutls-params file in the spool directory, because the
308older Exim will not recognize the new format.
309
c688b954
PH
3102. When doing a callout as part of verifying an address, Exim was not paying
311attention to any local part prefix or suffix that was matched by the router
312that accepted the address. It now behaves in the same way as it does for
313delivery: the affixes are removed from the local part unless
314rcpt_include_affixes is set on the transport. If you have a configuration that
315uses prefixes or suffixes on addresses that could be used for callouts, and you
316want the affixes to be retained, you must make sure that rcpt_include_affixes
317is set on the transport.
318
447d236c
PH
3193. Bounce and delay warning messages no longer contain details of delivery
320errors, except for explicit messages (e.g. generated by :fail:) and SMTP
321responses from remote hosts.
322
b5aea5e1 323
8b5af54d
PH
324Version 4.50
325------------
326
4964e932
PH
327The exicyclog script has been updated to use three-digit numbers in rotated log
328files if the maximum number to keep is greater than 99. If you are already
329keeping more than 99, there will be an incompatible change when you upgrade.
330You will probably want to rename your old log files to the new form before
c3af992c 331running the new exicyclog.
8b5af54d
PH
332
333
0f4f2a88
PH
334Version 4.42
335------------
336
337RFC 3848 specifies standard names for the "with" phrase in Received: header
338lines when AUTH and/or TLS are in use. This is the "received protocol"
339field. Exim used to use "asmtp" for authenticated SMTP, without any
340indication (in the protocol name) for TLS use. Now it follows the RFC and
341uses "esmtpa" if the connection is authenticated, "esmtps" if it is
342encrypted, and "esmtpsa" if it is both encrypted and authenticated. These names
343appear in log lines as well as in Received: header lines.
344
345
346Version 4.34
347------------
348
349Change 4.31/2 gave problems to data ACLs and local_scan() functions that
350expected to see a Received: header. I have changed to yet another scheme. The
351Received: header is now generated after the body is received, but before the
352ACL or local_scan() is called. After they have run, the timestamp in the
353Received: header is updated.
354
355Thus, change (a) of 4.31/2 has been reversed, but change (b) is still true,
356which is lucky, since I decided it was a bug fix.
357
358
359Version 4.33
360------------
361
362If an expansion in a condition on a "warn" statement fails because a lookup
363defers, the "warn" statement is abandoned, and the next ACL statement is
364processed. Previously this caused the whole ACL to be aborted.
365
366
367Version 4.32
368------------
369
370Change 4.31/2 has been reversed, as it proved contentious. Recipient callout
371verification now uses <> in the MAIL command by default, as it did before. A
372new callout option, "use_sender", has been added to request the other
373behaviour.
374
375
376Version 4.31
377------------
378
3791. If you compile Exim to use GnuTLS, it now requires the use of release 1.0.0
380 or greater. The interface to the obsolete 0.8.x releases is no longer
381 supported. There is one externally visible change: the format for the
382 display of Distinguished Names now uses commas as a separator rather than a
383 slash. This is to comply with RFC 2253.
384
3852. When a message is received, the Received: header line is now generated when
386 reception is complete, instead of at the start of reception. For messages
387 that take a long time to come in, this changes the meaning of the timestamp.
388 There are several side-effects of this change:
389
390 (a) If a message is rejected by a DATA or non-SMTP ACL, or by local_scan(),
391 the logged header lines no longer include the local Received: line,
392 because it has not yet been created. If the message is a non-SMTP one,
393 and the error is processed by sending a message to the sender, the copy
394 of the original message that is returned does not have an added
395 Received: line.
396
397 (b) When a filter file is tested using -bf, no additional Received: header
398 is added to the test message. After some thought, I decided that this
399 is a bug fix.
400
401 The contents of $received_for are not affected by this change. This
402 variable still contains the single recipient of a message, copied after
403 addresses have been rewritten, but before local_scan() is run.
404
4052. Recipient callout verification, like sender verification, was using <> in
406 the MAIL FROM command. This isn't really the right thing, since the actual
407 sender may affect whether the remote host accepts the recipient or not. I
408 have changed it to use the actual sender in the callout; this means that
409 the cache record is now keyed on a recipient/sender pair, not just the
410 recipient address. There doesn't seem to be a real danger of callout loops,
411 since a callout by the remote host to check the sender would use <>.
412
413
414Version 4.30
415------------
416
4171. I have abolished timeout_DNS as an error that can be detected in retry
418 rules, because it has never worked. Despite the fact that it has been
419 documented since at least release 1.62, there was no code to support it.
420 If you have used it in your retry rules, you will now get a warning message
421 to the log and panic log. It is now treated as plain "timeout".
422
4232. After discussion on the mailing list, Exim no longer adds From:, Date:, or
424 Message-Id: header lines to messages that do not originate locally, that is,
425 messages that have an associated sending host address.
426
4273. When looking up a host name from an IP address, Exim now tries the DNS
428 first, and only if that fails does it use gethostbyaddr() (or equivalent).
429 This change was made because on some OS, not all the names are given for
430 addresses with multiple PTR records via the gethostbyaddr() interface. The
431 order of lookup can be changed by setting host_lookup_order.
432
433
434Version 4.23
435------------
436
4371. The new FIXED_NEVER_USERS build-time option creates a list of "never users"
438 that cannot be overridden. The default in the distributed EDITME is "root".
439 If for some reason you were (against advice) running deliveries as root, you
440 will have to ensure that FIXED_NEVER_USERS is not set in your
441 Local/Makefile.
442
4432. The ${quote: operator now quotes an empty string, which it did not before.
444
4453. Version 4.23 saves the contents of the ACL variables with the message, so
446 that they can be used later. If one of these variables contains a newline,
447 there will be a newline character in the spool that will not be interpreted
448 correctely by a previous version of Exim. (Exim ignores keyed spool file
449 items that it doesn't understand - precisely for this kind of problem - but
450 it expects them all to be on one line.)
451
452 So the bottom line is: if you have newlines in your ACL variables, you
453 cannot retreat from 4.23.
454
455
456Version 4.21
457------------
458
4591. The idea of the "warn" ACL verb is that it adds a header or writes to the
460 log only when "message" or "log_message" are set. However, if one of the
461 conditions was an address verification, or a call to a nested ACL, the
462 messages generated by the underlying test were being passed through. This
463 no longer happens. The underlying message is available in $acl_verify_
464 message for both "message" and "log_message" expansions, so it can be
465 passed through if needed.
466
4672. The way that the $h_ (and $header_) expansions work has been changed by the
468 addition of RFC 2047 decoding. See the main documentation (the NewStuff file
469 until release 4.30, then the manual) for full details. Briefly, there are
470 now three forms:
471
472 $rh_xxx: and $rheader_xxx: give the original content of the header
473 line(s), with no processing at all.
474
475 $bh_xxx: and $bheader_xxx: remove leading and trailing white space, and
476 then decode base64 or quoted-printable "words" within the header text,
477 but do not do charset translation.
478
479 $h_xxx: and $header_xxx: attempt to translate the $bh_ string to a
480 standard character set.
481
482 If you have previously been using $h_ expansions to access the raw
483 characters, you should change to $rh_ instead.
484
4853. When Exim creates an RFC 2047 encoded word in a header line, it labels it
486 with the default character set from the headers_charset option instead of
487 always using iso-8859-1.
488
4894. If TMPDIR is defined in Local/Makefile (default in src/EDITME is
490 TMPDIR="/tmp"), Exim checks for the presence of an environment variable
491 called TMPDIR, and if it finds it is different, it changes its value.
492
4935. Following a discussion on the list, the rules by which Exim recognises line
494 endings on incoming messages have been changed. The -dropcr and drop_cr
495 options are now no-ops, retained only for backwards compatibility. The
496 following line terminators are recognized: LF CRLF CR. However, special
497 processing applies to CR:
498
499 (i) The sequence CR . CR does *not* terminate an incoming SMTP message,
500 nor a local message in the state where . is a terminator.
501
502 (ii) If a bare CR is encountered in a header line, an extra space is added
503 after the line terminator so as not to end the header. The reasoning
504 behind this is that bare CRs in header lines are most likely either
505 to be mistakes, or people trying to play silly games.
506
5076. The code for using daemon_smtp_port, local_interfaces, and the -oX options
508 has been reorganized. It is supposed to be backwards compatible, but it is
509 mentioned here just in case I've screwed up.
510
511
512
513Version 4.20
514------------
515
5161. I have tidied and re-organized the code that uses alarm() for imposing time
517 limits on various things. It shouldn't affect anything, but if you notice
518 processes getting stuck, it may be that I've broken something.
519
5202. The "arguments" log selector now also logs the current working directory
521 when Exim is called.
522
5233. An incompatible change has been made to the appendfile transport. This
524 affects the case when it is used for file deliveries that are set up by
525 .forward and filter files. Previously, any settings of the "file" or
526 "directory" options were ignored. It is hoped that, like the address_file
527 transport in the default configuration, these options were never in fact set
528 on such transports, because they were of no use.
529
530 Now, if either of these options is set, it is used. The path that is passed
531 by the router is in $address_file (this is not new), so it can be used as
532 part of a longer path, or modified in any other way that expansion permits.
533
534 If neither "file" nor "directory" is set, the behaviour is unchanged.
535
5364. Related to the above: in a filter, if a "save" command specifies a non-
537 absolute path, the value of $home/ is pre-pended. This no longer happens if
538 $home is unset or is set to an empty string.
539
5405. Multiple file deliveries from a filter or .forward file can never be
541 batched; the value of batch_max on the transport is ignored for file
542 deliveries. I'm assuming that nobody ever actually set batch_max on the
543 address_file transport - it would have had odd effects previously.
544
5456. DESTDIR is the more common variable that ROOT for use when installing
546 software under a different root filing system. The Exim install script now
547 recognizes DESTDIR first; if it is not set, ROOT is used.
548
5497. If DESTDIR is set when installing Exim, it no longer prepends its value to
550 the path of the system aliases file that appears in the default
551 configuration (when a default configuration is installed). If an aliases
552 file is actually created, its name *does* use the prefix.
553
554
555Version 4.14
556------------
557
5581. The default for the maximum number of unknown SMTP commands that Exim will
559accept before dropping a connection has been reduced from 5 to 3. However, you
560can now change the value by setting smtp_max_unknown_commands.
561
5622. The ${quote: operator has been changed so that it turns newline and carriage
563return characters into \n and \r, respectively.
564
5653. The file names used for maildir messages now include the microsecond time
566fraction as well as the time in seconds, to cope with systems where the process
567id can be re-used within the same second. The format is now
568
569 <time>.H<microsec>P<pid>.<host>
570
571This should be a compatible change, but is noted here just in case.
572
5734. The rules for creating message ids have changed, to cope with systems where
574the process id can be re-used within the same second. The format, however, is
575unchanged, so this should not cause any problems, except as noted in the next
576item.
577
5785. The maximum value for localhost_number has been reduced from 255 to 16, in
579order to implement the new message id rules. For operating systems that have
580case-insensitive file systems (Cygwin and Darwin), the limit is 10.
581
5826. verify = header_syntax was allowing unqualified addresses in all cases. Now
583it allows them only for locally generated messages and from hosts that match
584sender_unqualified_hosts or recipient_unqualified_hosts, respectively.
585
5867. For reasons lost in the mists of time, when a pipe transport was run, the
587environment variable MESSAGE_ID was set to the message ID preceded by 'E' (the
588form used in Message-ID: header lines). The 'E' has been removed.
589
590
591Version 4.11
592------------
593
5941. The handling of lines in the configuration file has changed. Previously,
595macro expansion was applied to logical lines, after continuations had been
596joined on. This meant that it could not be used in .include lines, which are
597handled as physical rather than logical lines. Macro expansion is now done on
598physical lines rather than logical lines. This means there are two
599incompatibilities:
600
601 (a) A macro that expands to # to turn a line into a comment now applies only
602 to the physical line where it appears. Previously, it would have caused
603 any following continuations also to be ignored.
604
605 (b) A macro name can no longer be split over the boundary between a line and
606 its continuation. Actually, this is more of a bug fix. :-)
607
6082. The -D command line option must now all be within one command line item.
609This makes it possible to use -D to set a macro to the empty string by commands
610such as
611
612 exim -DABC ...
613 exim -DABC= ...
614
615Previously, these items would have moved on to the next item on the command
616line. To include spaces in a macro definition item, quotes must be used, in
617which case you can also have spaces after -D and surrounding the equals. For
618example:
619
620 exim '-D ABC = something' ...
621
6223. The way that addresses that redirect to themselves are handled has been
623changed, in order to fix an obscure bug. This should not cause any problems
624except in the case of wanting to go back from a 4.11 (or later) release to an
625earlier release. If there are undelivered messages on the spool that contain
626addresses which redirect to themselves, and the redirected addresses have
627already been delivered, you might get a duplicate delivery if you revert to an
628earlier Exim.
629
6304. The default way of looking up IP addresses for hosts in the manualroute and
631queryprogram routers has been changed. If "byname" or "bydns" is explicitly
632specified, there is no change, but if no method is specified, Exim now behaves
633as follows:
634
635 First, a DNS lookup is done. If this yields anything other than
636 HOST_NOT_FOUND, that result is used. Otherwise, Exim goes on to try a call to
637 getipnodebyname() (or gethostbyname() on older systems) and the result of the
638 lookup is the result of that call.
639
640This change has been made because it has been discovered that on some systems,
641if a DNS lookup called via getipnodebyname() times out, HOST_NOT_FOUND is
642returned instead of TRY_AGAIN. Thus, it is safest to try a DNS lookup directly
643first, and only if that gives a definite "no such host" to try the local
644function.
645
6465. In fixing the minor security problem with pid_file_path, I have removed some
647backwards-compatible (undocumented) code which was present to ease conversion
648from Exim 3. In Exim 4, pid_file_path is a literal; in Exim 3 it was allowed to
649contain "%s", which was replaced by the port number for daemons listening on
650non-standard ports. In Exim 4, such daemons do not write a pid file. The
651backwards compatibility feature was to replace "%s" by nothing if it occurred
652in an Exim 4 setting of pid_file_path. The bug was in this code. I have solved
653the problem by removing the backwards compatibility feature. Thus, if you still
654have "%s" somewhere in a setting of pid_file_path, you should remove it.
655
6566. There has been an extension to lsearch files. The keys in these files may
657now be quoted in order to allow for whitespace and colons in them. This means
658that if you were previously using keys that began with a doublequote, you will
659now have to wrap them with extra quotes and escape the internal quotes. The
660possibility that anybody is actually doing this seems extremely remote, but it
661is documented just in case.
662
663
664Version 4.10
665------------
666
667The build-time parameter EXIWHAT_KILL_ARG has been renamed EXIWHAT_KILL_SIGNAL
668to better reflect its function. The OS-specific files have been updated. Only
669if you have explicitly set this in your Makefile (highly unlikely) do you need
670to change anything.
671
672****