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