Merge branch 'lists'
[exim.git] / doc / doc-txt / NewStuff
1 New Features in Exim
2 --------------------
3
4 This file contains descriptions of new features that have been added to Exim.
5 Before a formal release, there may be quite a lot of detail so that people can
6 test from the snapshots or the CVS before the documentation is updated. Once
7 the documentation is updated, this file is reduced to a short list.
8
9 Version 4.81
10 ------------
11
12 1. New command-line option -bI:sieve will list all supported sieve extensions
13 of this Exim build on standard output, one per line.
14 ManageSieve (RFC 5804) providers managing scripts for use by Exim should
15 query this to establish the correct list to include in the protocol's
16 SIEVE capability line.
17
18 2. If the -n option is combined with the -bP option, then the name of an
19 emitted option is not output, only the value (if visible to you).
20 For instance, "exim -n -bP pid_file_path" should just emit a pathname
21 followed by a newline, and no other text.
22
23 3. When built with SUPPORT_TLS and USE_GNUTLS, the SMTP transport driver now
24 has a "tls_dh_min_bits" option, to set the minimum acceptable number of
25 bits in the Diffie-Hellman prime offered by a server (in DH ciphersuites)
26 acceptable for security. (Option accepted but ignored if using OpenSSL).
27 Defaults to 1024, the old value. May be lowered only to 512, or raised as
28 far as you like. Raising this may hinder TLS interoperability with other
29 sites and is not currently recommended. Lowering this will permit you to
30 establish a TLS session which is not as secure as you might like.
31
32 Unless you really know what you are doing, leave it alone.
33
34 4. If not built with DISABLE_DNSSEC, Exim now has the main option
35 dns_use_dnssec; if set to 1 then Exim will initialise the resolver library
36 to send the DO flag to your recursive resolver. If you have a recursive
37 resolver, which can set the Authenticated Data (AD) flag in results, Exim
38 can now detect this.
39
40 Current status: work-in-progress; $sender_host_dnssec variable added.
41
42 5. DSCP support for outbound connections: on a transport using the smtp driver,
43 set "dscp = ef", for instance, to cause the connections to have the relevant
44 DSCP (IPv4 TOS or IPv6 TCLASS) value in the header.
45
46 Similarly for inbound connections, there is a new control modifier, dscp,
47 so "warn control = dscp/ef" in the connect ACL, or after authentication.
48
49 Supported values depend upon system libraries. "exim -bI:dscp" to list the
50 ones Exim knows of. You can also set a raw number 0..0x3F.
51
52 6. The -G command-line flag is no longer ignored; it is now equivalent to an
53 ACL setting "control = suppress_local_fixups". The -L command-line flag
54 is now accepted and forces use of syslog, with the provided tag as the
55 process name. A few other flags used by Sendmail are now accepted and
56 ignored.
57
58 7. New cutthrough routing feature. Requested by a "control = cutthrough_delivery"
59 ACL modifier; works for single-recipient mails which are recieved on and
60 deliverable via SMTP. Using the connection made for a recipient verify,
61 if requested before the verify, or a new one made for the purpose while
62 the inbound connection is still active. The bulk of the mail item is copied
63 direct from the inbound socket to the outbound (as well as the spool file).
64 When the source notifies the end of data, the data acceptance by the destination
65 is negociated before the acceptance is sent to the source. If the destination
66 does not accept the mail item, for example due to content-scanning, the item
67 is not accepted from the source and therefore there is no need to generate
68 a bounce mail. This is of benefit when providing a secondary-MX service.
69 The downside is that delays are under the control of the ultimate destination
70 system not your own.
71
72 The Recieved-by: header on items delivered by cutthrough is generated
73 early in reception rather than at the end; this will affect any timestamp
74 included. The log line showing delivery is recorded before that showing
75 reception; it uses a new ">>" tag instead of "=>".
76
77 To support the feature, verify-callout connections can now use ESMTP and TLS.
78 The usual smtp transport options are honoured, plus a (new, default everything)
79 hosts_verify_avoid_tls.
80
81 New variable families named tls_in_cipher, tls_out_cipher etc. are introduced
82 for specific access to the information for each connection. The old names
83 are present for now but deprecated.
84
85 Not yet supported: IGNOREQUOTA, SIZE, PIPELINING, AUTH.
86
87 8. New expansion operators ${listnamed:name} to get the content of a named list
88 and ${listcount:string} to count the items in a list.
89
90 Version 4.80
91 ------------
92
93 1. New authenticator driver, "gsasl". Server-only (at present).
94 This is a SASL interface, licensed under GPL, which can be found at
95 http://www.gnu.org/software/gsasl/.
96 This system does not provide sources of data for authentication, so
97 careful use needs to be made of the conditions in Exim.
98
99 2. New authenticator driver, "heimdal_gssapi". Server-only.
100 A replacement for using cyrus_sasl with Heimdal, now that $KRB5_KTNAME
101 is no longer honoured for setuid programs by Heimdal. Use the
102 "server_keytab" option to point to the keytab.
103
104 3. The "pkg-config" system can now be used when building Exim to reference
105 cflags and library information for lookups and authenticators, rather
106 than having to update "CFLAGS", "AUTH_LIBS", "LOOKUP_INCLUDE" and
107 "LOOKUP_LIBS" directly. Similarly for handling the TLS library support
108 without adjusting "TLS_INCLUDE" and "TLS_LIBS".
109
110 In addition, setting PCRE_CONFIG=yes will query the pcre-config tool to
111 find the headers and libraries for PCRE.
112
113 4. New expansion variable $tls_bits.
114
115 5. New lookup type, "dbmjz". Key is an Exim list, the elements of which will
116 be joined together with ASCII NUL characters to construct the key to pass
117 into the DBM library. Can be used with gsasl to access sasldb2 files as
118 used by Cyrus SASL.
119
120 6. OpenSSL now supports TLS1.1 and TLS1.2 with OpenSSL 1.0.1.
121
122 Avoid release 1.0.1a if you can. Note that the default value of
123 "openssl_options" is no longer "+dont_insert_empty_fragments", as that
124 increased susceptibility to attack. This may still have interoperability
125 implications for very old clients (see version 4.31 change 37) but
126 administrators can choose to make the trade-off themselves and restore
127 compatibility at the cost of session security.
128
129 7. Use of the new expansion variable $tls_sni in the main configuration option
130 tls_certificate will cause Exim to re-expand the option, if the client
131 sends the TLS Server Name Indication extension, to permit choosing a
132 different certificate; tls_privatekey will also be re-expanded. You must
133 still set these options to expand to valid files when $tls_sni is not set.
134
135 The SMTP Transport has gained the option tls_sni, which will set a hostname
136 for outbound TLS sessions, and set $tls_sni too.
137
138 A new log_selector, +tls_sni, has been added, to log received SNI values
139 for Exim as a server.
140
141 8. The existing "accept_8bitmime" option now defaults to true. This means
142 that Exim is deliberately not strictly RFC compliant. We're following
143 Dan Bernstein's advice in http://cr.yp.to/smtp/8bitmime.html by default.
144 Those who disagree, or know that they are talking to mail servers that,
145 even today, are not 8-bit clean, need to turn off this option.
146
147 9. Exim can now be started with -bw (with an optional timeout, given as
148 -bw<timespec>). With this, stdin at startup is a socket that is
149 already listening for connections. This has a more modern name of
150 "socket activation", but forcing the activated socket to fd 0. We're
151 interested in adding more support for modern variants.
152
153 10. ${eval } now uses 64-bit values on supporting platforms. A new "G" suffix
154 for numbers indicates multiplication by 1024^3.
155
156 11. The GnuTLS support has been revamped; the three options gnutls_require_kx,
157 gnutls_require_mac & gnutls_require_protocols are no longer supported.
158 tls_require_ciphers is now parsed by gnutls_priority_init(3) as a priority
159 string, documentation for which is at:
160 http://www.gnu.org/software/gnutls/manual/html_node/Priority-Strings.html
161
162 SNI support has been added to Exim's GnuTLS integration too.
163
164 For sufficiently recent GnuTLS libraries, ${randint:..} will now use
165 gnutls_rnd(), asking for GNUTLS_RND_NONCE level randomness.
166
167 12. With OpenSSL, if built with EXPERIMENTAL_OCSP, a new option tls_ocsp_file
168 is now available. If the contents of the file are valid, then Exim will
169 send that back in response to a TLS status request; this is OCSP Stapling.
170 Exim will not maintain the contents of the file in any way: administrators
171 are responsible for ensuring that it is up-to-date.
172
173 See "experimental-spec.txt" for more details.
174
175 13. ${lookup dnsdb{ }} supports now SPF record types. They are handled
176 identically to TXT record lookups.
177
178 14. New expansion variable $tod_epoch_l for higher-precision time.
179
180 15. New global option tls_dh_max_bits, defaulting to current value of NSS
181 hard-coded limit of DH ephemeral bits, to fix interop problems caused by
182 GnuTLS 2.12 library recommending a bit count higher than NSS supports.
183
184 16. tls_dhparam now used by both OpenSSL and GnuTLS, can be path or identifier.
185 Option can now be a path or an identifier for a standard prime.
186 If unset, we use the DH prime from section 2.2 of RFC 5114, "ike23".
187 Set to "historic" to get the old GnuTLS behaviour of auto-generated DH
188 primes.
189
190 17. SSLv2 now disabled by default in OpenSSL. (Never supported by GnuTLS).
191 Use "openssl_options -no_sslv2" to re-enable support, if your OpenSSL
192 install was not built with OPENSSL_NO_SSL2 ("no-ssl2").
193
194
195 Version 4.77
196 ------------
197
198 1. New options for the ratelimit ACL condition: /count= and /unique=.
199 The /noupdate option has been replaced by a /readonly option.
200
201 2. The SMTP transport's protocol option may now be set to "smtps", to
202 use SSL-on-connect outbound.
203
204 3. New variable $av_failed, set true if the AV scanner deferred; ie, when
205 there is a problem talking to the AV scanner, or the AV scanner running.
206
207 4. New expansion conditions, "inlist" and "inlisti", which take simple lists
208 and check if the search item is a member of the list. This does not
209 support named lists, but does subject the list part to string expansion.
210
211 5. Unless the new EXPAND_LISTMATCH_RHS build option is set when Exim was
212 built, Exim no longer performs string expansion on the second string of
213 the match_* expansion conditions: "match_address", "match_domain",
214 "match_ip" & "match_local_part". Named lists can still be used.
215
216
217 Version 4.76
218 ------------
219
220 1. The global option "dns_use_edns0" may be set to coerce EDNS0 usage on
221 or off in the resolver library.
222
223
224 Version 4.75
225 ------------
226
227 1. In addition to the existing LDAP and LDAP/SSL ("ldaps") support, there
228 is now LDAP/TLS support, given sufficiently modern OpenLDAP client
229 libraries. The following global options have been added in support of
230 this: ldap_ca_cert_dir, ldap_ca_cert_file, ldap_cert_file, ldap_cert_key,
231 ldap_cipher_suite, ldap_require_cert, ldap_start_tls.
232
233 2. The pipe transport now takes a boolean option, "freeze_signal", default
234 false. When true, if the external delivery command exits on a signal then
235 Exim will freeze the message in the queue, instead of generating a bounce.
236
237 3. Log filenames may now use %M as an escape, instead of %D (still available).
238 The %M pattern expands to yyyymm, providing month-level resolution.
239
240 4. The $message_linecount variable is now updated for the maildir_tag option,
241 in the same way as $message_size, to reflect the real number of lines,
242 including any header additions or removals from transport.
243
244 5. When contacting a pool of SpamAssassin servers configured in spamd_address,
245 Exim now selects entries randomly, to better scale in a cluster setup.
246
247
248 Version 4.74
249 ------------
250
251 1. SECURITY FIX: privilege escalation flaw fixed. On Linux (and only Linux)
252 the flaw permitted the Exim run-time user to cause root to append to
253 arbitrary files of the attacker's choosing, with the content based
254 on content supplied by the attacker.
255
256 2. Exim now supports loading some lookup types at run-time, using your
257 platform's dlopen() functionality. This has limited platform support
258 and the intention is not to support every variant, it's limited to
259 dlopen(). This permits the main Exim binary to not be linked against
260 all the libraries needed for all the lookup types.
261
262
263 Version 4.73
264 ------------
265
266 NOTE: this version is not guaranteed backwards-compatible, please read the
267 items below carefully
268
269 1. A new main configuration option, "openssl_options", is available if Exim
270 is built with SSL support provided by OpenSSL. The option allows
271 administrators to specify OpenSSL options to be used on connections;
272 typically this is to set bug compatibility features which the OpenSSL
273 developers have not enabled by default. There may be security
274 consequences for certain options, so these should not be changed
275 frivolously.
276
277 2. A new pipe transport option, "permit_coredumps", may help with problem
278 diagnosis in some scenarios. Note that Exim is typically installed as
279 a setuid binary, which on most OSes will inhibit coredumps by default,
280 so that safety mechanism would have to be overridden for this option to
281 be able to take effect.
282
283 3. ClamAV 0.95 is now required for ClamAV support in Exim, unless
284 Local/Makefile sets: WITH_OLD_CLAMAV_STREAM=yes
285 Note that this switches Exim to use a new API ("INSTREAM") and a future
286 release of ClamAV will remove support for the old API ("STREAM").
287
288 The av_scanner option, when set to "clamd", now takes an optional third
289 part, "local", which causes Exim to pass a filename to ClamAV instead of
290 the file content. This is the same behaviour as when clamd is pointed at
291 a Unix-domain socket. For example:
292
293 av_scanner = clamd:192.0.2.3 1234:local
294
295 ClamAV's ExtendedDetectionInfo response format is now handled.
296
297 4. There is now a -bmalware option, restricted to admin users. This option
298 takes one parameter, a filename, and scans that file with Exim's
299 malware-scanning framework. This is intended purely as a debugging aid
300 to ensure that Exim's scanning is working, not to replace other tools.
301 Note that the ACL framework is not invoked, so if av_scanner references
302 ACL variables without a fallback then this will fail.
303
304 5. There is a new expansion operator, "reverse_ip", which will reverse IP
305 addresses; IPv4 into dotted quad, IPv6 into dotted nibble. Examples:
306
307 ${reverse_ip:192.0.2.4}
308 -> 4.2.0.192
309 ${reverse_ip:2001:0db8:c42:9:1:abcd:192.0.2.3}
310 -> 3.0.2.0.0.0.0.c.d.c.b.a.1.0.0.0.9.0.0.0.2.4.c.0.8.b.d.0.1.0.0.2
311
312 6. There is a new ACL control called "debug", to enable debug logging.
313 This allows selective logging of certain incoming transactions within
314 production environments, with some care. It takes two options, "tag"
315 and "opts"; "tag" is included in the filename of the log and "opts"
316 is used as per the -d<options> command-line option. Examples, which
317 don't all make sense in all contexts:
318
319 control = debug
320 control = debug/tag=.$sender_host_address
321 control = debug/opts=+expand+acl
322 control = debug/tag=.$message_exim_id/opts=+expand
323
324 7. It has always been implicit in the design and the documentation that
325 "the Exim user" is not root. src/EDITME said that using root was
326 "very strongly discouraged". This is not enough to keep people from
327 shooting themselves in the foot in days when many don't configure Exim
328 themselves but via package build managers. The security consequences of
329 running various bits of network code are severe if there should be bugs in
330 them. As such, the Exim user may no longer be root. If configured
331 statically, Exim will refuse to build. If configured as ref:user then Exim
332 will exit shortly after start-up. If you must shoot yourself in the foot,
333 then henceforth you will have to maintain your own local patches to strip
334 the safeties off.
335
336 8. There is a new expansion operator, bool_lax{}. Where bool{} uses the ACL
337 condition logic to determine truth/failure and will fail to expand many
338 strings, bool_lax{} uses the router condition logic, where most strings
339 do evaluate true.
340 Note: bool{00} is false, bool_lax{00} is true.
341
342 9. Routers now support multiple "condition" tests,
343
344 10. There is now a runtime configuration option "tcp_wrappers_daemon_name".
345 Setting this allows an admin to define which entry in the tcpwrappers
346 config file will be used to control access to the daemon. This option
347 is only available when Exim is built with USE_TCP_WRAPPERS. The
348 default value is set at build time using the TCP_WRAPPERS_DAEMON_NAME
349 build option.
350
351 11. [POSSIBLE CONFIG BREAKAGE] The default value for system_filter_user is now
352 the Exim run-time user, instead of root.
353
354 12. [POSSIBLE CONFIG BREAKAGE] ALT_CONFIG_ROOT_ONLY is no longer optional and
355 is forced on. This is mitigated by the new build option
356 TRUSTED_CONFIG_LIST which defines a list of configuration files which
357 are trusted; one per line. If a config file is owned by root and matches
358 a pathname in the list, then it may be invoked by the Exim build-time
359 user without Exim relinquishing root privileges.
360
361 13. [POSSIBLE CONFIG BREAKAGE] The Exim user is no longer automatically
362 trusted to supply -D<Macro[=Value]> overrides on the command-line. Going
363 forward, we recommend using TRUSTED_CONFIG_LIST with shim configs that
364 include the main config. As a transition mechanism, we are temporarily
365 providing a work-around: the new build option WHITELIST_D_MACROS provides
366 a colon-separated list of macro names which may be overridden by the Exim
367 run-time user. The values of these macros are constrained to the regex
368 ^[A-Za-z0-9_/.-]*$ (which explicitly does allow for empty values).
369
370
371 Version 4.72
372 ------------
373
374 1. TWO SECURITY FIXES: one relating to mail-spools which are globally
375 writable, the other to locking of MBX folders (not mbox).
376
377 2. MySQL stored procedures are now supported.
378
379 3. The dkim_domain transport option is now a list, not a single string, and
380 messages will be signed for each element in the list (discarding
381 duplicates).
382
383 4. The 4.70 release unexpectedly changed the behaviour of dnsdb TXT lookups
384 in the presence of multiple character strings within the RR. Prior to 4.70,
385 only the first string would be returned. The dnsdb lookup now, by default,
386 preserves the pre-4.70 semantics, but also now takes an extended output
387 separator specification. The separator can be followed by a semicolon, to
388 concatenate the individual text strings together with no join character,
389 or by a comma and a second separator character, in which case the text
390 strings within a TXT record are joined on that second character.
391 Administrators are reminded that DNS provides no ordering guarantees
392 between multiple records in an RRset. For example:
393
394 foo.example. IN TXT "a" "b" "c"
395 foo.example. IN TXT "d" "e" "f"
396
397 ${lookup dnsdb{>/ txt=foo.example}} -> "a/d"
398 ${lookup dnsdb{>/; txt=foo.example}} -> "def/abc"
399 ${lookup dnsdb{>/,+ txt=foo.example}} -> "a+b+c/d+e+f"
400
401
402 Version 4.70 / 4.71
403 -------------------
404
405 1. Native DKIM support without an external library.
406 (Note that if no action to prevent it is taken, a straight upgrade will
407 result in DKIM verification of all signed incoming emails. See spec
408 for details on conditionally disabling)
409
410 2. Experimental DCC support via dccifd (contributed by Wolfgang Breyha).
411
412 3. There is now a bool{} expansion condition which maps certain strings to
413 true/false condition values (most likely of use in conjunction with the
414 and{} expansion operator).
415
416 4. The $spam_score, $spam_bar and $spam_report variables are now available
417 at delivery time.
418
419 5. exim -bP now supports "macros", "macro_list" or "macro MACRO_NAME" as
420 options, provided that Exim is invoked by an admin_user.
421
422 6. There is a new option gnutls_compat_mode, when linked against GnuTLS,
423 which increases compatibility with older clients at the cost of decreased
424 security. Don't set this unless you need to support such clients.
425
426 7. There is a new expansion operator, ${randint:...} which will produce a
427 "random" number less than the supplied integer. This randomness is
428 not guaranteed to be cryptographically strong, but depending upon how
429 Exim was built may be better than the most naive schemes.
430
431 8. Exim now explicitly ensures that SHA256 is available when linked against
432 OpenSSL.
433
434 9. The transport_filter_timeout option now applies to SMTP transports too.
435
436
437 Version 4.69
438 ------------
439
440 1. Preliminary DKIM support in Experimental.
441
442
443 Version 4.68
444 ------------
445
446 1. The body_linecount and body_zerocount C variables are now exported in the
447 local_scan API.
448
449 2. When a dnslists lookup succeeds, the key that was looked up is now placed
450 in $dnslist_matched. When the key is an IP address, it is not reversed in
451 this variable (though it is, of course, in the actual lookup). In simple
452 cases, for example:
453
454 deny dnslists = spamhaus.example
455
456 the key is also available in another variable (in this case,
457 $sender_host_address). In more complicated cases, however, this is not
458 true. For example, using a data lookup might generate a dnslists lookup
459 like this:
460
461 deny dnslists = spamhaus.example/<|192.168.1.2|192.168.6.7|...
462
463 If this condition succeeds, the value in $dnslist_matched might be
464 192.168.6.7 (for example).
465
466 3. Authenticators now have a client_condition option. When Exim is running as
467 a client, it skips an authenticator whose client_condition expansion yields
468 "0", "no", or "false". This can be used, for example, to skip plain text
469 authenticators when the connection is not encrypted by a setting such as:
470
471 client_condition = ${if !eq{$tls_cipher}{}}
472
473 Note that the 4.67 documentation states that $tls_cipher contains the
474 cipher used for incoming messages. In fact, during SMTP delivery, it
475 contains the cipher used for the delivery. The same is true for
476 $tls_peerdn.
477
478 4. There is now a -Mvc <message-id> option, which outputs a copy of the
479 message to the standard output, in RFC 2822 format. The option can be used
480 only by an admin user.
481
482 5. There is now a /noupdate option for the ratelimit ACL condition. It
483 computes the rate and checks the limit as normal, but it does not update
484 the saved data. This means that, in relevant ACLs, it is possible to lookup
485 the existence of a specified (or auto-generated) ratelimit key without
486 incrementing the ratelimit counter for that key.
487
488 In order for this to be useful, another ACL entry must set the rate
489 for the same key somewhere (otherwise it will always be zero).
490
491 Example:
492
493 acl_check_connect:
494 # Read the rate; if it doesn't exist or is below the maximum
495 # we update it below
496 deny ratelimit = 100 / 5m / strict / noupdate
497 log_message = RATE: $sender_rate / $sender_rate_period \
498 (max $sender_rate_limit)
499
500 [... some other logic and tests...]
501
502 warn ratelimit = 100 / 5m / strict / per_cmd
503 log_message = RATE UPDATE: $sender_rate / $sender_rate_period \
504 (max $sender_rate_limit)
505 condition = ${if le{$sender_rate}{$sender_rate_limit}}
506
507 accept
508
509 6. The variable $max_received_linelength contains the number of bytes in the
510 longest line that was received as part of the message, not counting the
511 line termination character(s).
512
513 7. Host lists can now include +ignore_defer and +include_defer, analagous to
514 +ignore_unknown and +include_unknown. These options should be used with
515 care, probably only in non-critical host lists such as whitelists.
516
517 8. There's a new option called queue_only_load_latch, which defaults true.
518 If set false when queue_only_load is greater than zero, Exim re-evaluates
519 the load for each incoming message in an SMTP session. Otherwise, once one
520 message is queued, the remainder are also.
521
522 9. There is a new ACL, specified by acl_smtp_notquit, which is run in most
523 cases when an SMTP session ends without sending QUIT. However, when Exim
524 itself is is bad trouble, such as being unable to write to its log files,
525 this ACL is not run, because it might try to do things (such as write to
526 log files) that make the situation even worse.
527
528 Like the QUIT ACL, this new ACL is provided to make it possible to gather
529 statistics. Whatever it returns (accept or deny) is immaterial. The "delay"
530 modifier is forbidden in this ACL.
531
532 When the NOTQUIT ACL is running, the variable $smtp_notquit_reason is set
533 to a string that indicates the reason for the termination of the SMTP
534 connection. The possible values are:
535
536 acl-drop Another ACL issued a "drop" command
537 bad-commands Too many unknown or non-mail commands
538 command-timeout Timeout while reading SMTP commands
539 connection-lost The SMTP connection has been lost
540 data-timeout Timeout while reading message data
541 local-scan-error The local_scan() function crashed
542 local-scan-timeout The local_scan() function timed out
543 signal-exit SIGTERM or SIGINT
544 synchronization-error SMTP synchronization error
545 tls-failed TLS failed to start
546
547 In most cases when an SMTP connection is closed without having received
548 QUIT, Exim sends an SMTP response message before actually closing the
549 connection. With the exception of acl-drop, the default message can be
550 overridden by the "message" modifier in the NOTQUIT ACL. In the case of a
551 "drop" verb in another ACL, it is the message from the other ACL that is
552 used.
553
554 10. For MySQL and PostgreSQL lookups, it is now possible to specify a list of
555 servers with individual queries. This is done by starting the query with
556 "servers=x:y:z;", where each item in the list may take one of two forms:
557
558 (1) If it is just a host name, the appropriate global option (mysql_servers
559 or pgsql_servers) is searched for a host of the same name, and the
560 remaining parameters (database, user, password) are taken from there.
561
562 (2) If it contains any slashes, it is taken as a complete parameter set.
563
564 The list of servers is used in exactly the same was as the global list.
565 Once a connection to a server has happened and a query has been
566 successfully executed, processing of the lookup ceases.
567
568 This feature is intended for use in master/slave situations where updates
569 are occurring, and one wants to update a master rather than a slave. If the
570 masters are in the list for reading, you might have:
571
572 mysql_servers = slave1/db/name/pw:slave2/db/name/pw:master/db/name/pw
573
574 In an updating lookup, you could then write
575
576 ${lookup mysql{servers=master; UPDATE ...}
577
578 If, on the other hand, the master is not to be used for reading lookups:
579
580 pgsql_servers = slave1/db/name/pw:slave2/db/name/pw
581
582 you can still update the master by
583
584 ${lookup pgsql{servers=master/db/name/pw; UPDATE ...}
585
586 11. The message_body_newlines option (default FALSE, for backwards
587 compatibility) can be used to control whether newlines are present in
588 $message_body and $message_body_end. If it is FALSE, they are replaced by
589 spaces.
590
591
592 Version 4.67
593 ------------
594
595 1. There is a new log selector called smtp_no_mail, which is not included in
596 the default setting. When it is set, a line is written to the main log
597 whenever an accepted SMTP connection terminates without having issued a
598 MAIL command.
599
600 2. When an item in a dnslists list is followed by = and & and a list of IP
601 addresses, the behaviour was not clear when the lookup returned more than
602 one IP address. This has been solved by the addition of == and =& for "all"
603 rather than the default "any" matching.
604
605 3. Up till now, the only control over which cipher suites GnuTLS uses has been
606 for the cipher algorithms. New options have been added to allow some of the
607 other parameters to be varied.
608
609 4. There is a new compile-time option called ENABLE_DISABLE_FSYNC. When it is
610 set, Exim compiles a runtime option called disable_fsync.
611
612 5. There is a new variable called $smtp_count_at_connection_start.
613
614 6. There's a new control called no_pipelining.
615
616 7. There are two new variables called $sending_ip_address and $sending_port.
617 These are set whenever an SMTP connection to another host has been set up.
618
619 8. The expansion of the helo_data option in the smtp transport now happens
620 after the connection to the server has been made.
621
622 9. There is a new expansion operator ${rfc2047d: that decodes strings that
623 are encoded as per RFC 2047.
624
625 10. There is a new log selector called "pid", which causes the current process
626 id to be added to every log line, in square brackets, immediately after the
627 time and date.
628
629 11. Exim has been modified so that it flushes SMTP output before implementing
630 a delay in an ACL. It also flushes the output before performing a callout,
631 as this can take a substantial time. These behaviours can be disabled by
632 obeying control = no_delay_flush or control = no_callout_flush,
633 respectively, at some earlier stage of the connection.
634
635 12. There are two new expansion conditions that iterate over a list. They are
636 called forany and forall.
637
638 13. There's a new global option called dsn_from that can be used to vary the
639 contents of From: lines in bounces and other automatically generated
640 messages ("delivery status notifications" - hence the name of the option).
641
642 14. The smtp transport has a new option called hosts_avoid_pipelining.
643
644 15. By default, exigrep does case-insensitive matches. There is now a -I option
645 that makes it case-sensitive.
646
647 16. A number of new features ("addresses", "map", "filter", and "reduce") have
648 been added to string expansions to make it easier to process lists of
649 items, typically addresses.
650
651 17. There's a new ACL modifier called "continue". It does nothing of itself,
652 and processing of the ACL always continues with the next condition or
653 modifier. It is provided so that the side effects of expanding its argument
654 can be used.
655
656 18. It is now possible to use newline and other control characters (those with
657 values less than 32, plus DEL) as separators in lists.
658
659 19. The exigrep utility now has a -v option, which inverts the matching
660 condition.
661
662 20. The host_find_failed option in the manualroute router can now be set to
663 "ignore".
664
665
666 Version 4.66
667 ------------
668
669 No new features were added to 4.66.
670
671
672 Version 4.65
673 ------------
674
675 No new features were added to 4.65.
676
677
678 Version 4.64
679 ------------
680
681 1. ACL variables can now be given arbitrary names, as long as they start with
682 "acl_c" or "acl_m" (for connection variables and message variables), are at
683 least six characters long, with the sixth character being either a digit or
684 an underscore.
685
686 2. There is a new ACL modifier called log_reject_target. It makes it possible
687 to specify which logs are used for messages about ACL rejections.
688
689 3. There is a new authenticator called "dovecot". This is an interface to the
690 authentication facility of the Dovecot POP/IMAP server, which can support a
691 number of authentication methods.
692
693 4. The variable $message_headers_raw provides a concatenation of all the
694 messages's headers without any decoding. This is in contrast to
695 $message_headers, which does RFC2047 decoding on the header contents.
696
697 5. In a DNS black list, if two domain names, comma-separated, are given, the
698 second is used first to do an initial check, making use of any IP value
699 restrictions that are set. If there is a match, the first domain is used,
700 without any IP value restrictions, to get the TXT record.
701
702 6. All authenticators now have a server_condition option.
703
704 7. There is a new command-line option called -Mset. It is useful only in
705 conjunction with -be (that is, when testing string expansions). It must be
706 followed by a message id; Exim loads the given message from its spool
707 before doing the expansions.
708
709 8. Another similar new command-line option is called -bem. It operates like
710 -be except that it must be followed by the name of a file that contains a
711 message.
712
713 9. When an address is delayed because of a 4xx response to a RCPT command, it
714 is now the combination of sender and recipient that is delayed in
715 subsequent queue runs until its retry time is reached.
716
717 10. Unary negation and the bitwise logical operators and, or, xor, not, and
718 shift, have been added to the eval: and eval10: expansion items.
719
720 11. The variables $interface_address and $interface_port have been renamed
721 as $received_ip_address and $received_port, to make it clear that they
722 relate to message reception rather than delivery. (The old names remain
723 available for compatibility.)
724
725 12. The "message" modifier can now be used on "accept" and "discard" acl verbs
726 to vary the message that is sent when an SMTP command is accepted.
727
728
729 Version 4.63
730 ------------
731
732 1. There is a new Boolean option called filter_prepend_home for the redirect
733 router.
734
735 2. There is a new acl, set by acl_not_smtp_start, which is run right at the
736 start of receiving a non-SMTP message, before any of the message has been
737 read.
738
739 3. When an SMTP error message is specified in a "message" modifier in an ACL,
740 or in a :fail: or :defer: message in a redirect router, Exim now checks the
741 start of the message for an SMTP error code.
742
743 4. There is a new parameter for LDAP lookups called "referrals", which takes
744 one of the settings "follow" (the default) or "nofollow".
745
746 5. Version 20070721.2 of exipick now included, offering these new options:
747 --reverse
748 After all other sorting options have bee processed, reverse order
749 before displaying messages (-R is synonym).
750 --random
751 Randomize order of matching messages before displaying.
752 --size
753 Instead of displaying the matching messages, display the sum
754 of their sizes.
755 --sort <variable>[,<variable>...]
756 Before displaying matching messages, sort the messages according to
757 each messages value for each variable.
758 --not
759 Negate the value for every test (returns inverse output from the
760 same criteria without --not).
761
762
763 Version 4.62
764 ------------
765
766 1. The ${readsocket expansion item now supports Internet domain sockets as well
767 as Unix domain sockets. If the first argument begins "inet:", it must be of
768 the form "inet:host:port". The port is mandatory; it may be a number or the
769 name of a TCP port in /etc/services. The host may be a name, or it may be an
770 IP address. An ip address may optionally be enclosed in square brackets.
771 This is best for IPv6 addresses. For example:
772
773 ${readsocket{inet:[::1]:1234}{<request data>}...
774
775 Only a single host name may be given, but if looking it up yield more than
776 one IP address, they are each tried in turn until a connection is made. Once
777 a connection has been made, the behaviour is as for ${readsocket with a Unix
778 domain socket.
779
780 2. If a redirect router sets up file or pipe deliveries for more than one
781 incoming address, and the relevant transport has batch_max set greater than
782 one, a batch delivery now occurs.
783
784 3. The appendfile transport has a new option called maildirfolder_create_regex.
785 Its value is a regular expression. For a maildir delivery, this is matched
786 against the maildir directory; if it matches, Exim ensures that a
787 maildirfolder file is created alongside the new, cur, and tmp directories.
788
789
790 Version 4.61
791 ------------
792
793 The documentation is up-to-date for the 4.61 release. Major new features since
794 the 4.60 release are:
795
796 . An option called disable_ipv6, to disable the use of IPv6 completely.
797
798 . An increase in the number of ACL variables to 20 of each type.
799
800 . A change to use $auth1, $auth2, and $auth3 in authenticators instead of $1,
801 $2, $3, (though those are still set) because the numeric variables get used
802 for other things in complicated expansions.
803
804 . The default for rfc1413_query_timeout has been changed from 30s to 5s.
805
806 . It is possible to use setclassresources() on some BSD OS to control the
807 resources used in pipe deliveries.
808
809 . A new ACL modifier called add_header, which can be used with any verb.
810
811 . More errors are detectable in retry rules.
812
813 There are a number of other additions too.
814
815
816 Version 4.60
817 ------------
818
819 The documentation is up-to-date for the 4.60 release. Major new features since
820 the 4.50 release are:
821
822 . Support for SQLite.
823
824 . Support for IGNOREQUOTA in LMTP.
825
826 . Extensions to the "submission mode" features.
827
828 . Support for Client SMTP Authorization (CSA).
829
830 . Support for ratelimiting hosts and users.
831
832 . New expansion items to help with the BATV "prvs" scheme.
833
834 . A "match_ip" condition, that matches an IP address against a list.
835
836 There are many more minor changes.
837
838 ****