Fix tls_required and lost_connection retry testss not working.
[exim.git] / src / README.UPDATING
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ebc9d865 1$Cambridge: exim/src/README.UPDATING,v 1.14 2006/09/26 14:51:02 ph10 Exp $
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2
3This document contains detailed information about incompatibilities that might
4be encountered when upgrading from one release of Exim to another. The
5information is in reverse order of release numbers. Mostly these are relatively
6small points, and the configuration file is normally upwards compatible, but
7there have been two big upheavals...
8
9
10**************************************************************************
11* There was a big reworking of the way mail routing works for release *
12* 4.00. Previously used "directors" were abolished, and all routing is *
13* now done by routers. Policy controls for incoming mail are now done by *
14* Access Control Lists instead of separate options. All this means that *
15* pre-4.00 configuration files have to be massively converted. If you *
16* are coming from a 3.xx release, please read the document in the file *
17* doc/Exim4.upgrade, and allow some time to complete the upgrade. *
18* *
19* There was a big reworking of the way domain/host/net/address lists are *
20* handled at release 3.00. If you are coming from a pre-3.00 release, it *
21* might be easier to start again from a default configuration. Otherwise *
22* you need to read doc/Exim3.upgrade and do a double conversion of your *
23* configuration file. *
24**************************************************************************
25
26
27The rest of this document contains information about changes in 4.xx releases
28that might affect a running system.
29
30
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31Exim version 4.64
32-----------------
33
341. Callouts were setting the name used for EHLO/HELO from $smtp_active_
35hostname. This is wrong, because it relates to the incoming message (and
36probably the interface on which it is arriving) and not to the outgoing
37callout (which could be using a different interface). This has been
38changed to use the value of the helo_data option from the smtp transport
39instead - this is what is used when a message is actually being sent. If
40there is no remote transport (possible with a router that sets up host
41addresses), $smtp_active_hostname is used. This change is mentioned here in
42case somebody is relying on the use of $smtp_active_hostname.
43
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442. A bug has been fixed that might just possibly be something that is relied on
45in some configurations. In expansion items such as ${if >{xxx}{yyy}...} an
46empty string (that is {}) was being interpreted as if it was {0} and therefore
47treated as the number zero. From release 4.64, such strings cause an error
48because a decimal number, possibly followed by K or M, is required (as has
49always been documented).
50
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52Exim version 4.63
53-----------------
54
55When an SMTP error message is specified in a "message" modifier in an ACL, or
56in a :fail: or :defer: message in a redirect router, Exim now checks the start
57of the message for an SMTP error code. This consists of three digits followed
58by a space, optionally followed by an extended code of the form n.n.n, also
59followed by a space. If this is the case and the very first digit is the same
60as the default error code, the code from the message is used instead. If the
61very first digit is incorrect, a panic error is logged, and the default code is
62used. This is an incompatible change, but it is not expected to affect many (if
63any) configurations. It is possible to suppress the use of the supplied code in
64a redirect router by setting the smtp_error_code option false. In this case,
65any SMTP code is quietly ignored.
66
67
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68Exim version 4.61
69-----------------
70
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711. The default number of ACL variables of each type has been increased to 20,
72and it's possible to compile Exim with more. You can safely upgrade to this
73release if you already have messages on the queue with saved ACL variable
74values. However, if you downgrade from this release with messages on the queue,
75any saved ACL values they may have will be lost.
76
772. The default value for rfc1413_query_timeout has been changed from 30s to 5s.
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78
79
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80Exim version 4.54
81-----------------
82
83There was a problem with 4.52/TF/02 in that a "name=" option on control=
84submission terminated at the next slash, thereby not allowing for slashes in
85the name. This has been changed so that "name=" takes the rest of the string as
86its data. It must therefore be the last option.
87
88
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89Version 4.53
90------------
91
92If you are using the experimental Domain Keys support, you must upgrade to
93at least libdomainkeys 0.67 in order to run this release of Exim.
94
95
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96Version 4.51
97------------
98
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991. The format in which GnuTLS parameters are cached (in the file gnutls-params
100in the spool directory) has been changed. The new format can also be generated
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101externally, so it is now possible to update the values from outside Exim. This
102has been implemented in an upwards, BUT NOT downwards, compatible manner.
103Upgrading should be seamless: when Exim finds that it cannot understand an
104existing cache file, it generates new parameters and writes them to the cache
105in the new format. If, however, you downgrade from 4.51 to a previous release,
106you MUST delete the gnutls-params file in the spool directory, because the
107older Exim will not recognize the new format.
108
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1092. When doing a callout as part of verifying an address, Exim was not paying
110attention to any local part prefix or suffix that was matched by the router
111that accepted the address. It now behaves in the same way as it does for
112delivery: the affixes are removed from the local part unless
113rcpt_include_affixes is set on the transport. If you have a configuration that
114uses prefixes or suffixes on addresses that could be used for callouts, and you
115want the affixes to be retained, you must make sure that rcpt_include_affixes
116is set on the transport.
117
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1183. Bounce and delay warning messages no longer contain details of delivery
119errors, except for explicit messages (e.g. generated by :fail:) and SMTP
120responses from remote hosts.
121
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123Version 4.50
124------------
125
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126The exicyclog script has been updated to use three-digit numbers in rotated log
127files if the maximum number to keep is greater than 99. If you are already
128keeping more than 99, there will be an incompatible change when you upgrade.
129You will probably want to rename your old log files to the new form before
c3af992c 130running the new exicyclog.
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131
132
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133Version 4.42
134------------
135
136RFC 3848 specifies standard names for the "with" phrase in Received: header
137lines when AUTH and/or TLS are in use. This is the "received protocol"
138field. Exim used to use "asmtp" for authenticated SMTP, without any
139indication (in the protocol name) for TLS use. Now it follows the RFC and
140uses "esmtpa" if the connection is authenticated, "esmtps" if it is
141encrypted, and "esmtpsa" if it is both encrypted and authenticated. These names
142appear in log lines as well as in Received: header lines.
143
144
145Version 4.34
146------------
147
148Change 4.31/2 gave problems to data ACLs and local_scan() functions that
149expected to see a Received: header. I have changed to yet another scheme. The
150Received: header is now generated after the body is received, but before the
151ACL or local_scan() is called. After they have run, the timestamp in the
152Received: header is updated.
153
154Thus, change (a) of 4.31/2 has been reversed, but change (b) is still true,
155which is lucky, since I decided it was a bug fix.
156
157
158Version 4.33
159------------
160
161If an expansion in a condition on a "warn" statement fails because a lookup
162defers, the "warn" statement is abandoned, and the next ACL statement is
163processed. Previously this caused the whole ACL to be aborted.
164
165
166Version 4.32
167------------
168
169Change 4.31/2 has been reversed, as it proved contentious. Recipient callout
170verification now uses <> in the MAIL command by default, as it did before. A
171new callout option, "use_sender", has been added to request the other
172behaviour.
173
174
175Version 4.31
176------------
177
1781. If you compile Exim to use GnuTLS, it now requires the use of release 1.0.0
179 or greater. The interface to the obsolete 0.8.x releases is no longer
180 supported. There is one externally visible change: the format for the
181 display of Distinguished Names now uses commas as a separator rather than a
182 slash. This is to comply with RFC 2253.
183
1842. When a message is received, the Received: header line is now generated when
185 reception is complete, instead of at the start of reception. For messages
186 that take a long time to come in, this changes the meaning of the timestamp.
187 There are several side-effects of this change:
188
189 (a) If a message is rejected by a DATA or non-SMTP ACL, or by local_scan(),
190 the logged header lines no longer include the local Received: line,
191 because it has not yet been created. If the message is a non-SMTP one,
192 and the error is processed by sending a message to the sender, the copy
193 of the original message that is returned does not have an added
194 Received: line.
195
196 (b) When a filter file is tested using -bf, no additional Received: header
197 is added to the test message. After some thought, I decided that this
198 is a bug fix.
199
200 The contents of $received_for are not affected by this change. This
201 variable still contains the single recipient of a message, copied after
202 addresses have been rewritten, but before local_scan() is run.
203
2042. Recipient callout verification, like sender verification, was using <> in
205 the MAIL FROM command. This isn't really the right thing, since the actual
206 sender may affect whether the remote host accepts the recipient or not. I
207 have changed it to use the actual sender in the callout; this means that
208 the cache record is now keyed on a recipient/sender pair, not just the
209 recipient address. There doesn't seem to be a real danger of callout loops,
210 since a callout by the remote host to check the sender would use <>.
211
212
213Version 4.30
214------------
215
2161. I have abolished timeout_DNS as an error that can be detected in retry
217 rules, because it has never worked. Despite the fact that it has been
218 documented since at least release 1.62, there was no code to support it.
219 If you have used it in your retry rules, you will now get a warning message
220 to the log and panic log. It is now treated as plain "timeout".
221
2222. After discussion on the mailing list, Exim no longer adds From:, Date:, or
223 Message-Id: header lines to messages that do not originate locally, that is,
224 messages that have an associated sending host address.
225
2263. When looking up a host name from an IP address, Exim now tries the DNS
227 first, and only if that fails does it use gethostbyaddr() (or equivalent).
228 This change was made because on some OS, not all the names are given for
229 addresses with multiple PTR records via the gethostbyaddr() interface. The
230 order of lookup can be changed by setting host_lookup_order.
231
232
233Version 4.23
234------------
235
2361. The new FIXED_NEVER_USERS build-time option creates a list of "never users"
237 that cannot be overridden. The default in the distributed EDITME is "root".
238 If for some reason you were (against advice) running deliveries as root, you
239 will have to ensure that FIXED_NEVER_USERS is not set in your
240 Local/Makefile.
241
2422. The ${quote: operator now quotes an empty string, which it did not before.
243
2443. Version 4.23 saves the contents of the ACL variables with the message, so
245 that they can be used later. If one of these variables contains a newline,
246 there will be a newline character in the spool that will not be interpreted
247 correctely by a previous version of Exim. (Exim ignores keyed spool file
248 items that it doesn't understand - precisely for this kind of problem - but
249 it expects them all to be on one line.)
250
251 So the bottom line is: if you have newlines in your ACL variables, you
252 cannot retreat from 4.23.
253
254
255Version 4.21
256------------
257
2581. The idea of the "warn" ACL verb is that it adds a header or writes to the
259 log only when "message" or "log_message" are set. However, if one of the
260 conditions was an address verification, or a call to a nested ACL, the
261 messages generated by the underlying test were being passed through. This
262 no longer happens. The underlying message is available in $acl_verify_
263 message for both "message" and "log_message" expansions, so it can be
264 passed through if needed.
265
2662. The way that the $h_ (and $header_) expansions work has been changed by the
267 addition of RFC 2047 decoding. See the main documentation (the NewStuff file
268 until release 4.30, then the manual) for full details. Briefly, there are
269 now three forms:
270
271 $rh_xxx: and $rheader_xxx: give the original content of the header
272 line(s), with no processing at all.
273
274 $bh_xxx: and $bheader_xxx: remove leading and trailing white space, and
275 then decode base64 or quoted-printable "words" within the header text,
276 but do not do charset translation.
277
278 $h_xxx: and $header_xxx: attempt to translate the $bh_ string to a
279 standard character set.
280
281 If you have previously been using $h_ expansions to access the raw
282 characters, you should change to $rh_ instead.
283
2843. When Exim creates an RFC 2047 encoded word in a header line, it labels it
285 with the default character set from the headers_charset option instead of
286 always using iso-8859-1.
287
2884. If TMPDIR is defined in Local/Makefile (default in src/EDITME is
289 TMPDIR="/tmp"), Exim checks for the presence of an environment variable
290 called TMPDIR, and if it finds it is different, it changes its value.
291
2925. Following a discussion on the list, the rules by which Exim recognises line
293 endings on incoming messages have been changed. The -dropcr and drop_cr
294 options are now no-ops, retained only for backwards compatibility. The
295 following line terminators are recognized: LF CRLF CR. However, special
296 processing applies to CR:
297
298 (i) The sequence CR . CR does *not* terminate an incoming SMTP message,
299 nor a local message in the state where . is a terminator.
300
301 (ii) If a bare CR is encountered in a header line, an extra space is added
302 after the line terminator so as not to end the header. The reasoning
303 behind this is that bare CRs in header lines are most likely either
304 to be mistakes, or people trying to play silly games.
305
3066. The code for using daemon_smtp_port, local_interfaces, and the -oX options
307 has been reorganized. It is supposed to be backwards compatible, but it is
308 mentioned here just in case I've screwed up.
309
310
311
312Version 4.20
313------------
314
3151. I have tidied and re-organized the code that uses alarm() for imposing time
316 limits on various things. It shouldn't affect anything, but if you notice
317 processes getting stuck, it may be that I've broken something.
318
3192. The "arguments" log selector now also logs the current working directory
320 when Exim is called.
321
3223. An incompatible change has been made to the appendfile transport. This
323 affects the case when it is used for file deliveries that are set up by
324 .forward and filter files. Previously, any settings of the "file" or
325 "directory" options were ignored. It is hoped that, like the address_file
326 transport in the default configuration, these options were never in fact set
327 on such transports, because they were of no use.
328
329 Now, if either of these options is set, it is used. The path that is passed
330 by the router is in $address_file (this is not new), so it can be used as
331 part of a longer path, or modified in any other way that expansion permits.
332
333 If neither "file" nor "directory" is set, the behaviour is unchanged.
334
3354. Related to the above: in a filter, if a "save" command specifies a non-
336 absolute path, the value of $home/ is pre-pended. This no longer happens if
337 $home is unset or is set to an empty string.
338
3395. Multiple file deliveries from a filter or .forward file can never be
340 batched; the value of batch_max on the transport is ignored for file
341 deliveries. I'm assuming that nobody ever actually set batch_max on the
342 address_file transport - it would have had odd effects previously.
343
3446. DESTDIR is the more common variable that ROOT for use when installing
345 software under a different root filing system. The Exim install script now
346 recognizes DESTDIR first; if it is not set, ROOT is used.
347
3487. If DESTDIR is set when installing Exim, it no longer prepends its value to
349 the path of the system aliases file that appears in the default
350 configuration (when a default configuration is installed). If an aliases
351 file is actually created, its name *does* use the prefix.
352
353
354Version 4.14
355------------
356
3571. The default for the maximum number of unknown SMTP commands that Exim will
358accept before dropping a connection has been reduced from 5 to 3. However, you
359can now change the value by setting smtp_max_unknown_commands.
360
3612. The ${quote: operator has been changed so that it turns newline and carriage
362return characters into \n and \r, respectively.
363
3643. The file names used for maildir messages now include the microsecond time
365fraction as well as the time in seconds, to cope with systems where the process
366id can be re-used within the same second. The format is now
367
368 <time>.H<microsec>P<pid>.<host>
369
370This should be a compatible change, but is noted here just in case.
371
3724. The rules for creating message ids have changed, to cope with systems where
373the process id can be re-used within the same second. The format, however, is
374unchanged, so this should not cause any problems, except as noted in the next
375item.
376
3775. The maximum value for localhost_number has been reduced from 255 to 16, in
378order to implement the new message id rules. For operating systems that have
379case-insensitive file systems (Cygwin and Darwin), the limit is 10.
380
3816. verify = header_syntax was allowing unqualified addresses in all cases. Now
382it allows them only for locally generated messages and from hosts that match
383sender_unqualified_hosts or recipient_unqualified_hosts, respectively.
384
3857. For reasons lost in the mists of time, when a pipe transport was run, the
386environment variable MESSAGE_ID was set to the message ID preceded by 'E' (the
387form used in Message-ID: header lines). The 'E' has been removed.
388
389
390Version 4.11
391------------
392
3931. The handling of lines in the configuration file has changed. Previously,
394macro expansion was applied to logical lines, after continuations had been
395joined on. This meant that it could not be used in .include lines, which are
396handled as physical rather than logical lines. Macro expansion is now done on
397physical lines rather than logical lines. This means there are two
398incompatibilities:
399
400 (a) A macro that expands to # to turn a line into a comment now applies only
401 to the physical line where it appears. Previously, it would have caused
402 any following continuations also to be ignored.
403
404 (b) A macro name can no longer be split over the boundary between a line and
405 its continuation. Actually, this is more of a bug fix. :-)
406
4072. The -D command line option must now all be within one command line item.
408This makes it possible to use -D to set a macro to the empty string by commands
409such as
410
411 exim -DABC ...
412 exim -DABC= ...
413
414Previously, these items would have moved on to the next item on the command
415line. To include spaces in a macro definition item, quotes must be used, in
416which case you can also have spaces after -D and surrounding the equals. For
417example:
418
419 exim '-D ABC = something' ...
420
4213. The way that addresses that redirect to themselves are handled has been
422changed, in order to fix an obscure bug. This should not cause any problems
423except in the case of wanting to go back from a 4.11 (or later) release to an
424earlier release. If there are undelivered messages on the spool that contain
425addresses which redirect to themselves, and the redirected addresses have
426already been delivered, you might get a duplicate delivery if you revert to an
427earlier Exim.
428
4294. The default way of looking up IP addresses for hosts in the manualroute and
430queryprogram routers has been changed. If "byname" or "bydns" is explicitly
431specified, there is no change, but if no method is specified, Exim now behaves
432as follows:
433
434 First, a DNS lookup is done. If this yields anything other than
435 HOST_NOT_FOUND, that result is used. Otherwise, Exim goes on to try a call to
436 getipnodebyname() (or gethostbyname() on older systems) and the result of the
437 lookup is the result of that call.
438
439This change has been made because it has been discovered that on some systems,
440if a DNS lookup called via getipnodebyname() times out, HOST_NOT_FOUND is
441returned instead of TRY_AGAIN. Thus, it is safest to try a DNS lookup directly
442first, and only if that gives a definite "no such host" to try the local
443function.
444
4455. In fixing the minor security problem with pid_file_path, I have removed some
446backwards-compatible (undocumented) code which was present to ease conversion
447from Exim 3. In Exim 4, pid_file_path is a literal; in Exim 3 it was allowed to
448contain "%s", which was replaced by the port number for daemons listening on
449non-standard ports. In Exim 4, such daemons do not write a pid file. The
450backwards compatibility feature was to replace "%s" by nothing if it occurred
451in an Exim 4 setting of pid_file_path. The bug was in this code. I have solved
452the problem by removing the backwards compatibility feature. Thus, if you still
453have "%s" somewhere in a setting of pid_file_path, you should remove it.
454
4556. There has been an extension to lsearch files. The keys in these files may
456now be quoted in order to allow for whitespace and colons in them. This means
457that if you were previously using keys that began with a doublequote, you will
458now have to wrap them with extra quotes and escape the internal quotes. The
459possibility that anybody is actually doing this seems extremely remote, but it
460is documented just in case.
461
462
463Version 4.10
464------------
465
466The build-time parameter EXIWHAT_KILL_ARG has been renamed EXIWHAT_KILL_SIGNAL
467to better reflect its function. The OS-specific files have been updated. Only
468if you have explicitly set this in your Makefile (highly unlikely) do you need
469to change anything.
470
471****