7675e599a23aac3b7ed105303a4a7829bd80c760
[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 4.82
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 ${listcount:string} to count the items in a list.
89
90 9. New global option "gnutls_enable_pkcs11", defaults false. The GnuTLS
91 rewrite in 4.80 combines with GnuTLS 2.12.0 or later, to autoload PKCS11
92 modules. For some situations this is desirable, but we expect admin in
93 those situations to know they want the feature. More commonly, it means
94 that GUI user modules get loaded and are broken by the setuid Exim being
95 unable to access files specified in environment variables and passed
96 through, thus breakage. So we explicitly inhibit the PKCS11 initialisation
97 unless this new option is set.
98
99 10. The "acl = name" condition on an ACL now supports optional arguments.
100 New expansion item "${acl {name}{arg}...}" and expansion condition
101 "acl {{name}{arg}...}" are added. In all cases up to nine arguments
102 can be used, appearing in $acl_arg1 to $acl_arg9 for the called ACL.
103 Variable $acl_narg contains the number of arguments. If the ACL sets
104 a "message =" value this becomes the result of the expansion item,
105 or the value of $value for the expansion condition. If the ACL returns
106 accept the expansion condition is true; if reject, false. A defer
107 return results in a forced fail.
108
109 11. Routers and transports can now have multiple headers_add and headers_remove
110 option lines. The concatenated list is used.
111
112 12. New ACL modifier "remove_header" can remove headers before message gets
113 handled by routers/transports.
114
115 13. New dnsdb lookup pseudo-type "a+". A sequence of "a6" (if configured),
116 "aaaa" and "a" lookups is done and the full set of results returned.
117
118 14. New expansion variable $headers_added with content from ACL add_header
119 modifier (but not yet added to messsage).
120
121 15. New 8bitmime status logging option for received messages. Log field "M8S".
122
123
124 16. New authenticated_sender logging option, adding to log field "A".
125
126 17. New expansion variables $router_name and $transport_name. Useful
127 particularly for debug_print as -bt commandline option does not
128 require privilege whereas -d does.
129
130
131
132 Version 4.80
133 ------------
134
135 1. New authenticator driver, "gsasl". Server-only (at present).
136 This is a SASL interface, licensed under GPL, which can be found at
137 http://www.gnu.org/software/gsasl/.
138 This system does not provide sources of data for authentication, so
139 careful use needs to be made of the conditions in Exim.
140
141 2. New authenticator driver, "heimdal_gssapi". Server-only.
142 A replacement for using cyrus_sasl with Heimdal, now that $KRB5_KTNAME
143 is no longer honoured for setuid programs by Heimdal. Use the
144 "server_keytab" option to point to the keytab.
145
146 3. The "pkg-config" system can now be used when building Exim to reference
147 cflags and library information for lookups and authenticators, rather
148 than having to update "CFLAGS", "AUTH_LIBS", "LOOKUP_INCLUDE" and
149 "LOOKUP_LIBS" directly. Similarly for handling the TLS library support
150 without adjusting "TLS_INCLUDE" and "TLS_LIBS".
151
152 In addition, setting PCRE_CONFIG=yes will query the pcre-config tool to
153 find the headers and libraries for PCRE.
154
155 4. New expansion variable $tls_bits.
156
157 5. New lookup type, "dbmjz". Key is an Exim list, the elements of which will
158 be joined together with ASCII NUL characters to construct the key to pass
159 into the DBM library. Can be used with gsasl to access sasldb2 files as
160 used by Cyrus SASL.
161
162 6. OpenSSL now supports TLS1.1 and TLS1.2 with OpenSSL 1.0.1.
163
164 Avoid release 1.0.1a if you can. Note that the default value of
165 "openssl_options" is no longer "+dont_insert_empty_fragments", as that
166 increased susceptibility to attack. This may still have interoperability
167 implications for very old clients (see version 4.31 change 37) but
168 administrators can choose to make the trade-off themselves and restore
169 compatibility at the cost of session security.
170
171 7. Use of the new expansion variable $tls_sni in the main configuration option
172 tls_certificate will cause Exim to re-expand the option, if the client
173 sends the TLS Server Name Indication extension, to permit choosing a
174 different certificate; tls_privatekey will also be re-expanded. You must
175 still set these options to expand to valid files when $tls_sni is not set.
176
177 The SMTP Transport has gained the option tls_sni, which will set a hostname
178 for outbound TLS sessions, and set $tls_sni too.
179
180 A new log_selector, +tls_sni, has been added, to log received SNI values
181 for Exim as a server.
182
183 8. The existing "accept_8bitmime" option now defaults to true. This means
184 that Exim is deliberately not strictly RFC compliant. We're following
185 Dan Bernstein's advice in http://cr.yp.to/smtp/8bitmime.html by default.
186 Those who disagree, or know that they are talking to mail servers that,
187 even today, are not 8-bit clean, need to turn off this option.
188
189 9. Exim can now be started with -bw (with an optional timeout, given as
190 -bw<timespec>). With this, stdin at startup is a socket that is
191 already listening for connections. This has a more modern name of
192 "socket activation", but forcing the activated socket to fd 0. We're
193 interested in adding more support for modern variants.
194
195 10. ${eval } now uses 64-bit values on supporting platforms. A new "G" suffix
196 for numbers indicates multiplication by 1024^3.
197
198 11. The GnuTLS support has been revamped; the three options gnutls_require_kx,
199 gnutls_require_mac & gnutls_require_protocols are no longer supported.
200 tls_require_ciphers is now parsed by gnutls_priority_init(3) as a priority
201 string, documentation for which is at:
202 http://www.gnu.org/software/gnutls/manual/html_node/Priority-Strings.html
203
204 SNI support has been added to Exim's GnuTLS integration too.
205
206 For sufficiently recent GnuTLS libraries, ${randint:..} will now use
207 gnutls_rnd(), asking for GNUTLS_RND_NONCE level randomness.
208
209 12. With OpenSSL, if built with EXPERIMENTAL_OCSP, a new option tls_ocsp_file
210 is now available. If the contents of the file are valid, then Exim will
211 send that back in response to a TLS status request; this is OCSP Stapling.
212 Exim will not maintain the contents of the file in any way: administrators
213 are responsible for ensuring that it is up-to-date.
214
215 See "experimental-spec.txt" for more details.
216
217 13. ${lookup dnsdb{ }} supports now SPF record types. They are handled
218 identically to TXT record lookups.
219
220 14. New expansion variable $tod_epoch_l for higher-precision time.
221
222 15. New global option tls_dh_max_bits, defaulting to current value of NSS
223 hard-coded limit of DH ephemeral bits, to fix interop problems caused by
224 GnuTLS 2.12 library recommending a bit count higher than NSS supports.
225
226 16. tls_dhparam now used by both OpenSSL and GnuTLS, can be path or identifier.
227 Option can now be a path or an identifier for a standard prime.
228 If unset, we use the DH prime from section 2.2 of RFC 5114, "ike23".
229 Set to "historic" to get the old GnuTLS behaviour of auto-generated DH
230 primes.
231
232 17. SSLv2 now disabled by default in OpenSSL. (Never supported by GnuTLS).
233 Use "openssl_options -no_sslv2" to re-enable support, if your OpenSSL
234 install was not built with OPENSSL_NO_SSL2 ("no-ssl2").
235
236
237 Version 4.77
238 ------------
239
240 1. New options for the ratelimit ACL condition: /count= and /unique=.
241 The /noupdate option has been replaced by a /readonly option.
242
243 2. The SMTP transport's protocol option may now be set to "smtps", to
244 use SSL-on-connect outbound.
245
246 3. New variable $av_failed, set true if the AV scanner deferred; ie, when
247 there is a problem talking to the AV scanner, or the AV scanner running.
248
249 4. New expansion conditions, "inlist" and "inlisti", which take simple lists
250 and check if the search item is a member of the list. This does not
251 support named lists, but does subject the list part to string expansion.
252
253 5. Unless the new EXPAND_LISTMATCH_RHS build option is set when Exim was
254 built, Exim no longer performs string expansion on the second string of
255 the match_* expansion conditions: "match_address", "match_domain",
256 "match_ip" & "match_local_part". Named lists can still be used.
257
258
259 Version 4.76
260 ------------
261
262 1. The global option "dns_use_edns0" may be set to coerce EDNS0 usage on
263 or off in the resolver library.
264
265
266 Version 4.75
267 ------------
268
269 1. In addition to the existing LDAP and LDAP/SSL ("ldaps") support, there
270 is now LDAP/TLS support, given sufficiently modern OpenLDAP client
271 libraries. The following global options have been added in support of
272 this: ldap_ca_cert_dir, ldap_ca_cert_file, ldap_cert_file, ldap_cert_key,
273 ldap_cipher_suite, ldap_require_cert, ldap_start_tls.
274
275 2. The pipe transport now takes a boolean option, "freeze_signal", default
276 false. When true, if the external delivery command exits on a signal then
277 Exim will freeze the message in the queue, instead of generating a bounce.
278
279 3. Log filenames may now use %M as an escape, instead of %D (still available).
280 The %M pattern expands to yyyymm, providing month-level resolution.
281
282 4. The $message_linecount variable is now updated for the maildir_tag option,
283 in the same way as $message_size, to reflect the real number of lines,
284 including any header additions or removals from transport.
285
286 5. When contacting a pool of SpamAssassin servers configured in spamd_address,
287 Exim now selects entries randomly, to better scale in a cluster setup.
288
289
290 Version 4.74
291 ------------
292
293 1. SECURITY FIX: privilege escalation flaw fixed. On Linux (and only Linux)
294 the flaw permitted the Exim run-time user to cause root to append to
295 arbitrary files of the attacker's choosing, with the content based
296 on content supplied by the attacker.
297
298 2. Exim now supports loading some lookup types at run-time, using your
299 platform's dlopen() functionality. This has limited platform support
300 and the intention is not to support every variant, it's limited to
301 dlopen(). This permits the main Exim binary to not be linked against
302 all the libraries needed for all the lookup types.
303
304
305 Version 4.73
306 ------------
307
308 NOTE: this version is not guaranteed backwards-compatible, please read the
309 items below carefully
310
311 1. A new main configuration option, "openssl_options", is available if Exim
312 is built with SSL support provided by OpenSSL. The option allows
313 administrators to specify OpenSSL options to be used on connections;
314 typically this is to set bug compatibility features which the OpenSSL
315 developers have not enabled by default. There may be security
316 consequences for certain options, so these should not be changed
317 frivolously.
318
319 2. A new pipe transport option, "permit_coredumps", may help with problem
320 diagnosis in some scenarios. Note that Exim is typically installed as
321 a setuid binary, which on most OSes will inhibit coredumps by default,
322 so that safety mechanism would have to be overridden for this option to
323 be able to take effect.
324
325 3. ClamAV 0.95 is now required for ClamAV support in Exim, unless
326 Local/Makefile sets: WITH_OLD_CLAMAV_STREAM=yes
327 Note that this switches Exim to use a new API ("INSTREAM") and a future
328 release of ClamAV will remove support for the old API ("STREAM").
329
330 The av_scanner option, when set to "clamd", now takes an optional third
331 part, "local", which causes Exim to pass a filename to ClamAV instead of
332 the file content. This is the same behaviour as when clamd is pointed at
333 a Unix-domain socket. For example:
334
335 av_scanner = clamd:192.0.2.3 1234:local
336
337 ClamAV's ExtendedDetectionInfo response format is now handled.
338
339 4. There is now a -bmalware option, restricted to admin users. This option
340 takes one parameter, a filename, and scans that file with Exim's
341 malware-scanning framework. This is intended purely as a debugging aid
342 to ensure that Exim's scanning is working, not to replace other tools.
343 Note that the ACL framework is not invoked, so if av_scanner references
344 ACL variables without a fallback then this will fail.
345
346 5. There is a new expansion operator, "reverse_ip", which will reverse IP
347 addresses; IPv4 into dotted quad, IPv6 into dotted nibble. Examples:
348
349 ${reverse_ip:192.0.2.4}
350 -> 4.2.0.192
351 ${reverse_ip:2001:0db8:c42:9:1:abcd:192.0.2.3}
352 -> 3.0.2.0.0.0.0.c.d.c.b.a.1.0.0.0.9.0.0.0.2.4.c.0.8.b.d.0.1.0.0.2
353
354 6. There is a new ACL control called "debug", to enable debug logging.
355 This allows selective logging of certain incoming transactions within
356 production environments, with some care. It takes two options, "tag"
357 and "opts"; "tag" is included in the filename of the log and "opts"
358 is used as per the -d<options> command-line option. Examples, which
359 don't all make sense in all contexts:
360
361 control = debug
362 control = debug/tag=.$sender_host_address
363 control = debug/opts=+expand+acl
364 control = debug/tag=.$message_exim_id/opts=+expand
365
366 7. It has always been implicit in the design and the documentation that
367 "the Exim user" is not root. src/EDITME said that using root was
368 "very strongly discouraged". This is not enough to keep people from
369 shooting themselves in the foot in days when many don't configure Exim
370 themselves but via package build managers. The security consequences of
371 running various bits of network code are severe if there should be bugs in
372 them. As such, the Exim user may no longer be root. If configured
373 statically, Exim will refuse to build. If configured as ref:user then Exim
374 will exit shortly after start-up. If you must shoot yourself in the foot,
375 then henceforth you will have to maintain your own local patches to strip
376 the safeties off.
377
378 8. There is a new expansion condition, bool_lax{}. Where bool{} uses the ACL
379 condition logic to determine truth/failure and will fail to expand many
380 strings, bool_lax{} uses the router condition logic, where most strings
381 do evaluate true.
382 Note: bool{00} is false, bool_lax{00} is true.
383
384 9. Routers now support multiple "condition" tests.
385
386 10. There is now a runtime configuration option "tcp_wrappers_daemon_name".
387 Setting this allows an admin to define which entry in the tcpwrappers
388 config file will be used to control access to the daemon. This option
389 is only available when Exim is built with USE_TCP_WRAPPERS. The
390 default value is set at build time using the TCP_WRAPPERS_DAEMON_NAME
391 build option.
392
393 11. [POSSIBLE CONFIG BREAKAGE] The default value for system_filter_user is now
394 the Exim run-time user, instead of root.
395
396 12. [POSSIBLE CONFIG BREAKAGE] ALT_CONFIG_ROOT_ONLY is no longer optional and
397 is forced on. This is mitigated by the new build option
398 TRUSTED_CONFIG_LIST which defines a list of configuration files which
399 are trusted; one per line. If a config file is owned by root and matches
400 a pathname in the list, then it may be invoked by the Exim build-time
401 user without Exim relinquishing root privileges.
402
403 13. [POSSIBLE CONFIG BREAKAGE] The Exim user is no longer automatically
404 trusted to supply -D<Macro[=Value]> overrides on the command-line. Going
405 forward, we recommend using TRUSTED_CONFIG_LIST with shim configs that
406 include the main config. As a transition mechanism, we are temporarily
407 providing a work-around: the new build option WHITELIST_D_MACROS provides
408 a colon-separated list of macro names which may be overridden by the Exim
409 run-time user. The values of these macros are constrained to the regex
410 ^[A-Za-z0-9_/.-]*$ (which explicitly does allow for empty values).
411
412
413 Version 4.72
414 ------------
415
416 1. TWO SECURITY FIXES: one relating to mail-spools which are globally
417 writable, the other to locking of MBX folders (not mbox).
418
419 2. MySQL stored procedures are now supported.
420
421 3. The dkim_domain transport option is now a list, not a single string, and
422 messages will be signed for each element in the list (discarding
423 duplicates).
424
425 4. The 4.70 release unexpectedly changed the behaviour of dnsdb TXT lookups
426 in the presence of multiple character strings within the RR. Prior to 4.70,
427 only the first string would be returned. The dnsdb lookup now, by default,
428 preserves the pre-4.70 semantics, but also now takes an extended output
429 separator specification. The separator can be followed by a semicolon, to
430 concatenate the individual text strings together with no join character,
431 or by a comma and a second separator character, in which case the text
432 strings within a TXT record are joined on that second character.
433 Administrators are reminded that DNS provides no ordering guarantees
434 between multiple records in an RRset. For example:
435
436 foo.example. IN TXT "a" "b" "c"
437 foo.example. IN TXT "d" "e" "f"
438
439 ${lookup dnsdb{>/ txt=foo.example}} -> "a/d"
440 ${lookup dnsdb{>/; txt=foo.example}} -> "def/abc"
441 ${lookup dnsdb{>/,+ txt=foo.example}} -> "a+b+c/d+e+f"
442
443
444 Version 4.70 / 4.71
445 -------------------
446
447 1. Native DKIM support without an external library.
448 (Note that if no action to prevent it is taken, a straight upgrade will
449 result in DKIM verification of all signed incoming emails. See spec
450 for details on conditionally disabling)
451
452 2. Experimental DCC support via dccifd (contributed by Wolfgang Breyha).
453
454 3. There is now a bool{} expansion condition which maps certain strings to
455 true/false condition values (most likely of use in conjunction with the
456 and{} expansion operator).
457
458 4. The $spam_score, $spam_bar and $spam_report variables are now available
459 at delivery time.
460
461 5. exim -bP now supports "macros", "macro_list" or "macro MACRO_NAME" as
462 options, provided that Exim is invoked by an admin_user.
463
464 6. There is a new option gnutls_compat_mode, when linked against GnuTLS,
465 which increases compatibility with older clients at the cost of decreased
466 security. Don't set this unless you need to support such clients.
467
468 7. There is a new expansion operator, ${randint:...} which will produce a
469 "random" number less than the supplied integer. This randomness is
470 not guaranteed to be cryptographically strong, but depending upon how
471 Exim was built may be better than the most naive schemes.
472
473 8. Exim now explicitly ensures that SHA256 is available when linked against
474 OpenSSL.
475
476 9. The transport_filter_timeout option now applies to SMTP transports too.
477
478
479 Version 4.69
480 ------------
481
482 1. Preliminary DKIM support in Experimental.
483
484
485 Version 4.68
486 ------------
487
488 1. The body_linecount and body_zerocount C variables are now exported in the
489 local_scan API.
490
491 2. When a dnslists lookup succeeds, the key that was looked up is now placed
492 in $dnslist_matched. When the key is an IP address, it is not reversed in
493 this variable (though it is, of course, in the actual lookup). In simple
494 cases, for example:
495
496 deny dnslists = spamhaus.example
497
498 the key is also available in another variable (in this case,
499 $sender_host_address). In more complicated cases, however, this is not
500 true. For example, using a data lookup might generate a dnslists lookup
501 like this:
502
503 deny dnslists = spamhaus.example/<|192.168.1.2|192.168.6.7|...
504
505 If this condition succeeds, the value in $dnslist_matched might be
506 192.168.6.7 (for example).
507
508 3. Authenticators now have a client_condition option. When Exim is running as
509 a client, it skips an authenticator whose client_condition expansion yields
510 "0", "no", or "false". This can be used, for example, to skip plain text
511 authenticators when the connection is not encrypted by a setting such as:
512
513 client_condition = ${if !eq{$tls_cipher}{}}
514
515 Note that the 4.67 documentation states that $tls_cipher contains the
516 cipher used for incoming messages. In fact, during SMTP delivery, it
517 contains the cipher used for the delivery. The same is true for
518 $tls_peerdn.
519
520 4. There is now a -Mvc <message-id> option, which outputs a copy of the
521 message to the standard output, in RFC 2822 format. The option can be used
522 only by an admin user.
523
524 5. There is now a /noupdate option for the ratelimit ACL condition. It
525 computes the rate and checks the limit as normal, but it does not update
526 the saved data. This means that, in relevant ACLs, it is possible to lookup
527 the existence of a specified (or auto-generated) ratelimit key without
528 incrementing the ratelimit counter for that key.
529
530 In order for this to be useful, another ACL entry must set the rate
531 for the same key somewhere (otherwise it will always be zero).
532
533 Example:
534
535 acl_check_connect:
536 # Read the rate; if it doesn't exist or is below the maximum
537 # we update it below
538 deny ratelimit = 100 / 5m / strict / noupdate
539 log_message = RATE: $sender_rate / $sender_rate_period \
540 (max $sender_rate_limit)
541
542 [... some other logic and tests...]
543
544 warn ratelimit = 100 / 5m / strict / per_cmd
545 log_message = RATE UPDATE: $sender_rate / $sender_rate_period \
546 (max $sender_rate_limit)
547 condition = ${if le{$sender_rate}{$sender_rate_limit}}
548
549 accept
550
551 6. The variable $max_received_linelength contains the number of bytes in the
552 longest line that was received as part of the message, not counting the
553 line termination character(s).
554
555 7. Host lists can now include +ignore_defer and +include_defer, analagous to
556 +ignore_unknown and +include_unknown. These options should be used with
557 care, probably only in non-critical host lists such as whitelists.
558
559 8. There's a new option called queue_only_load_latch, which defaults true.
560 If set false when queue_only_load is greater than zero, Exim re-evaluates
561 the load for each incoming message in an SMTP session. Otherwise, once one
562 message is queued, the remainder are also.
563
564 9. There is a new ACL, specified by acl_smtp_notquit, which is run in most
565 cases when an SMTP session ends without sending QUIT. However, when Exim
566 itself is is bad trouble, such as being unable to write to its log files,
567 this ACL is not run, because it might try to do things (such as write to
568 log files) that make the situation even worse.
569
570 Like the QUIT ACL, this new ACL is provided to make it possible to gather
571 statistics. Whatever it returns (accept or deny) is immaterial. The "delay"
572 modifier is forbidden in this ACL.
573
574 When the NOTQUIT ACL is running, the variable $smtp_notquit_reason is set
575 to a string that indicates the reason for the termination of the SMTP
576 connection. The possible values are:
577
578 acl-drop Another ACL issued a "drop" command
579 bad-commands Too many unknown or non-mail commands
580 command-timeout Timeout while reading SMTP commands
581 connection-lost The SMTP connection has been lost
582 data-timeout Timeout while reading message data
583 local-scan-error The local_scan() function crashed
584 local-scan-timeout The local_scan() function timed out
585 signal-exit SIGTERM or SIGINT
586 synchronization-error SMTP synchronization error
587 tls-failed TLS failed to start
588
589 In most cases when an SMTP connection is closed without having received
590 QUIT, Exim sends an SMTP response message before actually closing the
591 connection. With the exception of acl-drop, the default message can be
592 overridden by the "message" modifier in the NOTQUIT ACL. In the case of a
593 "drop" verb in another ACL, it is the message from the other ACL that is
594 used.
595
596 10. For MySQL and PostgreSQL lookups, it is now possible to specify a list of
597 servers with individual queries. This is done by starting the query with
598 "servers=x:y:z;", where each item in the list may take one of two forms:
599
600 (1) If it is just a host name, the appropriate global option (mysql_servers
601 or pgsql_servers) is searched for a host of the same name, and the
602 remaining parameters (database, user, password) are taken from there.
603
604 (2) If it contains any slashes, it is taken as a complete parameter set.
605
606 The list of servers is used in exactly the same was as the global list.
607 Once a connection to a server has happened and a query has been
608 successfully executed, processing of the lookup ceases.
609
610 This feature is intended for use in master/slave situations where updates
611 are occurring, and one wants to update a master rather than a slave. If the
612 masters are in the list for reading, you might have:
613
614 mysql_servers = slave1/db/name/pw:slave2/db/name/pw:master/db/name/pw
615
616 In an updating lookup, you could then write
617
618 ${lookup mysql{servers=master; UPDATE ...}
619
620 If, on the other hand, the master is not to be used for reading lookups:
621
622 pgsql_servers = slave1/db/name/pw:slave2/db/name/pw
623
624 you can still update the master by
625
626 ${lookup pgsql{servers=master/db/name/pw; UPDATE ...}
627
628 11. The message_body_newlines option (default FALSE, for backwards
629 compatibility) can be used to control whether newlines are present in
630 $message_body and $message_body_end. If it is FALSE, they are replaced by
631 spaces.
632
633
634 Version 4.67
635 ------------
636
637 1. There is a new log selector called smtp_no_mail, which is not included in
638 the default setting. When it is set, a line is written to the main log
639 whenever an accepted SMTP connection terminates without having issued a
640 MAIL command.
641
642 2. When an item in a dnslists list is followed by = and & and a list of IP
643 addresses, the behaviour was not clear when the lookup returned more than
644 one IP address. This has been solved by the addition of == and =& for "all"
645 rather than the default "any" matching.
646
647 3. Up till now, the only control over which cipher suites GnuTLS uses has been
648 for the cipher algorithms. New options have been added to allow some of the
649 other parameters to be varied.
650
651 4. There is a new compile-time option called ENABLE_DISABLE_FSYNC. When it is
652 set, Exim compiles a runtime option called disable_fsync.
653
654 5. There is a new variable called $smtp_count_at_connection_start.
655
656 6. There's a new control called no_pipelining.
657
658 7. There are two new variables called $sending_ip_address and $sending_port.
659 These are set whenever an SMTP connection to another host has been set up.
660
661 8. The expansion of the helo_data option in the smtp transport now happens
662 after the connection to the server has been made.
663
664 9. There is a new expansion operator ${rfc2047d: that decodes strings that
665 are encoded as per RFC 2047.
666
667 10. There is a new log selector called "pid", which causes the current process
668 id to be added to every log line, in square brackets, immediately after the
669 time and date.
670
671 11. Exim has been modified so that it flushes SMTP output before implementing
672 a delay in an ACL. It also flushes the output before performing a callout,
673 as this can take a substantial time. These behaviours can be disabled by
674 obeying control = no_delay_flush or control = no_callout_flush,
675 respectively, at some earlier stage of the connection.
676
677 12. There are two new expansion conditions that iterate over a list. They are
678 called forany and forall.
679
680 13. There's a new global option called dsn_from that can be used to vary the
681 contents of From: lines in bounces and other automatically generated
682 messages ("delivery status notifications" - hence the name of the option).
683
684 14. The smtp transport has a new option called hosts_avoid_pipelining.
685
686 15. By default, exigrep does case-insensitive matches. There is now a -I option
687 that makes it case-sensitive.
688
689 16. A number of new features ("addresses", "map", "filter", and "reduce") have
690 been added to string expansions to make it easier to process lists of
691 items, typically addresses.
692
693 17. There's a new ACL modifier called "continue". It does nothing of itself,
694 and processing of the ACL always continues with the next condition or
695 modifier. It is provided so that the side effects of expanding its argument
696 can be used.
697
698 18. It is now possible to use newline and other control characters (those with
699 values less than 32, plus DEL) as separators in lists.
700
701 19. The exigrep utility now has a -v option, which inverts the matching
702 condition.
703
704 20. The host_find_failed option in the manualroute router can now be set to
705 "ignore".
706
707
708 Version 4.66
709 ------------
710
711 No new features were added to 4.66.
712
713
714 Version 4.65
715 ------------
716
717 No new features were added to 4.65.
718
719
720 Version 4.64
721 ------------
722
723 1. ACL variables can now be given arbitrary names, as long as they start with
724 "acl_c" or "acl_m" (for connection variables and message variables), are at
725 least six characters long, with the sixth character being either a digit or
726 an underscore.
727
728 2. There is a new ACL modifier called log_reject_target. It makes it possible
729 to specify which logs are used for messages about ACL rejections.
730
731 3. There is a new authenticator called "dovecot". This is an interface to the
732 authentication facility of the Dovecot POP/IMAP server, which can support a
733 number of authentication methods.
734
735 4. The variable $message_headers_raw provides a concatenation of all the
736 messages's headers without any decoding. This is in contrast to
737 $message_headers, which does RFC2047 decoding on the header contents.
738
739 5. In a DNS black list, if two domain names, comma-separated, are given, the
740 second is used first to do an initial check, making use of any IP value
741 restrictions that are set. If there is a match, the first domain is used,
742 without any IP value restrictions, to get the TXT record.
743
744 6. All authenticators now have a server_condition option.
745
746 7. There is a new command-line option called -Mset. It is useful only in
747 conjunction with -be (that is, when testing string expansions). It must be
748 followed by a message id; Exim loads the given message from its spool
749 before doing the expansions.
750
751 8. Another similar new command-line option is called -bem. It operates like
752 -be except that it must be followed by the name of a file that contains a
753 message.
754
755 9. When an address is delayed because of a 4xx response to a RCPT command, it
756 is now the combination of sender and recipient that is delayed in
757 subsequent queue runs until its retry time is reached.
758
759 10. Unary negation and the bitwise logical operators and, or, xor, not, and
760 shift, have been added to the eval: and eval10: expansion items.
761
762 11. The variables $interface_address and $interface_port have been renamed
763 as $received_ip_address and $received_port, to make it clear that they
764 relate to message reception rather than delivery. (The old names remain
765 available for compatibility.)
766
767 12. The "message" modifier can now be used on "accept" and "discard" acl verbs
768 to vary the message that is sent when an SMTP command is accepted.
769
770
771 Version 4.63
772 ------------
773
774 1. There is a new Boolean option called filter_prepend_home for the redirect
775 router.
776
777 2. There is a new acl, set by acl_not_smtp_start, which is run right at the
778 start of receiving a non-SMTP message, before any of the message has been
779 read.
780
781 3. When an SMTP error message is specified in a "message" modifier in an ACL,
782 or in a :fail: or :defer: message in a redirect router, Exim now checks the
783 start of the message for an SMTP error code.
784
785 4. There is a new parameter for LDAP lookups called "referrals", which takes
786 one of the settings "follow" (the default) or "nofollow".
787
788 5. Version 20070721.2 of exipick now included, offering these new options:
789 --reverse
790 After all other sorting options have bee processed, reverse order
791 before displaying messages (-R is synonym).
792 --random
793 Randomize order of matching messages before displaying.
794 --size
795 Instead of displaying the matching messages, display the sum
796 of their sizes.
797 --sort <variable>[,<variable>...]
798 Before displaying matching messages, sort the messages according to
799 each messages value for each variable.
800 --not
801 Negate the value for every test (returns inverse output from the
802 same criteria without --not).
803
804
805 Version 4.62
806 ------------
807
808 1. The ${readsocket expansion item now supports Internet domain sockets as well
809 as Unix domain sockets. If the first argument begins "inet:", it must be of
810 the form "inet:host:port". The port is mandatory; it may be a number or the
811 name of a TCP port in /etc/services. The host may be a name, or it may be an
812 IP address. An ip address may optionally be enclosed in square brackets.
813 This is best for IPv6 addresses. For example:
814
815 ${readsocket{inet:[::1]:1234}{<request data>}...
816
817 Only a single host name may be given, but if looking it up yield more than
818 one IP address, they are each tried in turn until a connection is made. Once
819 a connection has been made, the behaviour is as for ${readsocket with a Unix
820 domain socket.
821
822 2. If a redirect router sets up file or pipe deliveries for more than one
823 incoming address, and the relevant transport has batch_max set greater than
824 one, a batch delivery now occurs.
825
826 3. The appendfile transport has a new option called maildirfolder_create_regex.
827 Its value is a regular expression. For a maildir delivery, this is matched
828 against the maildir directory; if it matches, Exim ensures that a
829 maildirfolder file is created alongside the new, cur, and tmp directories.
830
831
832 Version 4.61
833 ------------
834
835 The documentation is up-to-date for the 4.61 release. Major new features since
836 the 4.60 release are:
837
838 . An option called disable_ipv6, to disable the use of IPv6 completely.
839
840 . An increase in the number of ACL variables to 20 of each type.
841
842 . A change to use $auth1, $auth2, and $auth3 in authenticators instead of $1,
843 $2, $3, (though those are still set) because the numeric variables get used
844 for other things in complicated expansions.
845
846 . The default for rfc1413_query_timeout has been changed from 30s to 5s.
847
848 . It is possible to use setclassresources() on some BSD OS to control the
849 resources used in pipe deliveries.
850
851 . A new ACL modifier called add_header, which can be used with any verb.
852
853 . More errors are detectable in retry rules.
854
855 There are a number of other additions too.
856
857
858 Version 4.60
859 ------------
860
861 The documentation is up-to-date for the 4.60 release. Major new features since
862 the 4.50 release are:
863
864 . Support for SQLite.
865
866 . Support for IGNOREQUOTA in LMTP.
867
868 . Extensions to the "submission mode" features.
869
870 . Support for Client SMTP Authorization (CSA).
871
872 . Support for ratelimiting hosts and users.
873
874 . New expansion items to help with the BATV "prvs" scheme.
875
876 . A "match_ip" condition, that matches an IP address against a list.
877
878 There are many more minor changes.
879
880 ****