Bug 1339: DCC update (Wolfgang Breyha)
[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 16. New authenticated_sender logging option, adding to log field "A".
124
125 17. New expansion variables $router_name and $transport_name. Useful
126 particularly for debug_print as -bt commandline option does not
127 require privilege whereas -d does.
128
129 18. If built with EXPERIMENTAL_PRDR, per-recipient data responses per a
130 proposed extension to SMTP from Eric Hall.
131
132
133 Version 4.80
134 ------------
135
136 1. New authenticator driver, "gsasl". Server-only (at present).
137 This is a SASL interface, licensed under GPL, which can be found at
138 http://www.gnu.org/software/gsasl/.
139 This system does not provide sources of data for authentication, so
140 careful use needs to be made of the conditions in Exim.
141
142 2. New authenticator driver, "heimdal_gssapi". Server-only.
143 A replacement for using cyrus_sasl with Heimdal, now that $KRB5_KTNAME
144 is no longer honoured for setuid programs by Heimdal. Use the
145 "server_keytab" option to point to the keytab.
146
147 3. The "pkg-config" system can now be used when building Exim to reference
148 cflags and library information for lookups and authenticators, rather
149 than having to update "CFLAGS", "AUTH_LIBS", "LOOKUP_INCLUDE" and
150 "LOOKUP_LIBS" directly. Similarly for handling the TLS library support
151 without adjusting "TLS_INCLUDE" and "TLS_LIBS".
152
153 In addition, setting PCRE_CONFIG=yes will query the pcre-config tool to
154 find the headers and libraries for PCRE.
155
156 4. New expansion variable $tls_bits.
157
158 5. New lookup type, "dbmjz". Key is an Exim list, the elements of which will
159 be joined together with ASCII NUL characters to construct the key to pass
160 into the DBM library. Can be used with gsasl to access sasldb2 files as
161 used by Cyrus SASL.
162
163 6. OpenSSL now supports TLS1.1 and TLS1.2 with OpenSSL 1.0.1.
164
165 Avoid release 1.0.1a if you can. Note that the default value of
166 "openssl_options" is no longer "+dont_insert_empty_fragments", as that
167 increased susceptibility to attack. This may still have interoperability
168 implications for very old clients (see version 4.31 change 37) but
169 administrators can choose to make the trade-off themselves and restore
170 compatibility at the cost of session security.
171
172 7. Use of the new expansion variable $tls_sni in the main configuration option
173 tls_certificate will cause Exim to re-expand the option, if the client
174 sends the TLS Server Name Indication extension, to permit choosing a
175 different certificate; tls_privatekey will also be re-expanded. You must
176 still set these options to expand to valid files when $tls_sni is not set.
177
178 The SMTP Transport has gained the option tls_sni, which will set a hostname
179 for outbound TLS sessions, and set $tls_sni too.
180
181 A new log_selector, +tls_sni, has been added, to log received SNI values
182 for Exim as a server.
183
184 8. The existing "accept_8bitmime" option now defaults to true. This means
185 that Exim is deliberately not strictly RFC compliant. We're following
186 Dan Bernstein's advice in http://cr.yp.to/smtp/8bitmime.html by default.
187 Those who disagree, or know that they are talking to mail servers that,
188 even today, are not 8-bit clean, need to turn off this option.
189
190 9. Exim can now be started with -bw (with an optional timeout, given as
191 -bw<timespec>). With this, stdin at startup is a socket that is
192 already listening for connections. This has a more modern name of
193 "socket activation", but forcing the activated socket to fd 0. We're
194 interested in adding more support for modern variants.
195
196 10. ${eval } now uses 64-bit values on supporting platforms. A new "G" suffix
197 for numbers indicates multiplication by 1024^3.
198
199 11. The GnuTLS support has been revamped; the three options gnutls_require_kx,
200 gnutls_require_mac & gnutls_require_protocols are no longer supported.
201 tls_require_ciphers is now parsed by gnutls_priority_init(3) as a priority
202 string, documentation for which is at:
203 http://www.gnu.org/software/gnutls/manual/html_node/Priority-Strings.html
204
205 SNI support has been added to Exim's GnuTLS integration too.
206
207 For sufficiently recent GnuTLS libraries, ${randint:..} will now use
208 gnutls_rnd(), asking for GNUTLS_RND_NONCE level randomness.
209
210 12. With OpenSSL, if built with EXPERIMENTAL_OCSP, a new option tls_ocsp_file
211 is now available. If the contents of the file are valid, then Exim will
212 send that back in response to a TLS status request; this is OCSP Stapling.
213 Exim will not maintain the contents of the file in any way: administrators
214 are responsible for ensuring that it is up-to-date.
215
216 See "experimental-spec.txt" for more details.
217
218 13. ${lookup dnsdb{ }} supports now SPF record types. They are handled
219 identically to TXT record lookups.
220
221 14. New expansion variable $tod_epoch_l for higher-precision time.
222
223 15. New global option tls_dh_max_bits, defaulting to current value of NSS
224 hard-coded limit of DH ephemeral bits, to fix interop problems caused by
225 GnuTLS 2.12 library recommending a bit count higher than NSS supports.
226
227 16. tls_dhparam now used by both OpenSSL and GnuTLS, can be path or identifier.
228 Option can now be a path or an identifier for a standard prime.
229 If unset, we use the DH prime from section 2.2 of RFC 5114, "ike23".
230 Set to "historic" to get the old GnuTLS behaviour of auto-generated DH
231 primes.
232
233 17. SSLv2 now disabled by default in OpenSSL. (Never supported by GnuTLS).
234 Use "openssl_options -no_sslv2" to re-enable support, if your OpenSSL
235 install was not built with OPENSSL_NO_SSL2 ("no-ssl2").
236
237
238 Version 4.77
239 ------------
240
241 1. New options for the ratelimit ACL condition: /count= and /unique=.
242 The /noupdate option has been replaced by a /readonly option.
243
244 2. The SMTP transport's protocol option may now be set to "smtps", to
245 use SSL-on-connect outbound.
246
247 3. New variable $av_failed, set true if the AV scanner deferred; ie, when
248 there is a problem talking to the AV scanner, or the AV scanner running.
249
250 4. New expansion conditions, "inlist" and "inlisti", which take simple lists
251 and check if the search item is a member of the list. This does not
252 support named lists, but does subject the list part to string expansion.
253
254 5. Unless the new EXPAND_LISTMATCH_RHS build option is set when Exim was
255 built, Exim no longer performs string expansion on the second string of
256 the match_* expansion conditions: "match_address", "match_domain",
257 "match_ip" & "match_local_part". Named lists can still be used.
258
259
260 Version 4.76
261 ------------
262
263 1. The global option "dns_use_edns0" may be set to coerce EDNS0 usage on
264 or off in the resolver library.
265
266
267 Version 4.75
268 ------------
269
270 1. In addition to the existing LDAP and LDAP/SSL ("ldaps") support, there
271 is now LDAP/TLS support, given sufficiently modern OpenLDAP client
272 libraries. The following global options have been added in support of
273 this: ldap_ca_cert_dir, ldap_ca_cert_file, ldap_cert_file, ldap_cert_key,
274 ldap_cipher_suite, ldap_require_cert, ldap_start_tls.
275
276 2. The pipe transport now takes a boolean option, "freeze_signal", default
277 false. When true, if the external delivery command exits on a signal then
278 Exim will freeze the message in the queue, instead of generating a bounce.
279
280 3. Log filenames may now use %M as an escape, instead of %D (still available).
281 The %M pattern expands to yyyymm, providing month-level resolution.
282
283 4. The $message_linecount variable is now updated for the maildir_tag option,
284 in the same way as $message_size, to reflect the real number of lines,
285 including any header additions or removals from transport.
286
287 5. When contacting a pool of SpamAssassin servers configured in spamd_address,
288 Exim now selects entries randomly, to better scale in a cluster setup.
289
290
291 Version 4.74
292 ------------
293
294 1. SECURITY FIX: privilege escalation flaw fixed. On Linux (and only Linux)
295 the flaw permitted the Exim run-time user to cause root to append to
296 arbitrary files of the attacker's choosing, with the content based
297 on content supplied by the attacker.
298
299 2. Exim now supports loading some lookup types at run-time, using your
300 platform's dlopen() functionality. This has limited platform support
301 and the intention is not to support every variant, it's limited to
302 dlopen(). This permits the main Exim binary to not be linked against
303 all the libraries needed for all the lookup types.
304
305
306 Version 4.73
307 ------------
308
309 NOTE: this version is not guaranteed backwards-compatible, please read the
310 items below carefully
311
312 1. A new main configuration option, "openssl_options", is available if Exim
313 is built with SSL support provided by OpenSSL. The option allows
314 administrators to specify OpenSSL options to be used on connections;
315 typically this is to set bug compatibility features which the OpenSSL
316 developers have not enabled by default. There may be security
317 consequences for certain options, so these should not be changed
318 frivolously.
319
320 2. A new pipe transport option, "permit_coredumps", may help with problem
321 diagnosis in some scenarios. Note that Exim is typically installed as
322 a setuid binary, which on most OSes will inhibit coredumps by default,
323 so that safety mechanism would have to be overridden for this option to
324 be able to take effect.
325
326 3. ClamAV 0.95 is now required for ClamAV support in Exim, unless
327 Local/Makefile sets: WITH_OLD_CLAMAV_STREAM=yes
328 Note that this switches Exim to use a new API ("INSTREAM") and a future
329 release of ClamAV will remove support for the old API ("STREAM").
330
331 The av_scanner option, when set to "clamd", now takes an optional third
332 part, "local", which causes Exim to pass a filename to ClamAV instead of
333 the file content. This is the same behaviour as when clamd is pointed at
334 a Unix-domain socket. For example:
335
336 av_scanner = clamd:192.0.2.3 1234:local
337
338 ClamAV's ExtendedDetectionInfo response format is now handled.
339
340 4. There is now a -bmalware option, restricted to admin users. This option
341 takes one parameter, a filename, and scans that file with Exim's
342 malware-scanning framework. This is intended purely as a debugging aid
343 to ensure that Exim's scanning is working, not to replace other tools.
344 Note that the ACL framework is not invoked, so if av_scanner references
345 ACL variables without a fallback then this will fail.
346
347 5. There is a new expansion operator, "reverse_ip", which will reverse IP
348 addresses; IPv4 into dotted quad, IPv6 into dotted nibble. Examples:
349
350 ${reverse_ip:192.0.2.4}
351 -> 4.2.0.192
352 ${reverse_ip:2001:0db8:c42:9:1:abcd:192.0.2.3}
353 -> 3.0.2.0.0.0.0.c.d.c.b.a.1.0.0.0.9.0.0.0.2.4.c.0.8.b.d.0.1.0.0.2
354
355 6. There is a new ACL control called "debug", to enable debug logging.
356 This allows selective logging of certain incoming transactions within
357 production environments, with some care. It takes two options, "tag"
358 and "opts"; "tag" is included in the filename of the log and "opts"
359 is used as per the -d<options> command-line option. Examples, which
360 don't all make sense in all contexts:
361
362 control = debug
363 control = debug/tag=.$sender_host_address
364 control = debug/opts=+expand+acl
365 control = debug/tag=.$message_exim_id/opts=+expand
366
367 7. It has always been implicit in the design and the documentation that
368 "the Exim user" is not root. src/EDITME said that using root was
369 "very strongly discouraged". This is not enough to keep people from
370 shooting themselves in the foot in days when many don't configure Exim
371 themselves but via package build managers. The security consequences of
372 running various bits of network code are severe if there should be bugs in
373 them. As such, the Exim user may no longer be root. If configured
374 statically, Exim will refuse to build. If configured as ref:user then Exim
375 will exit shortly after start-up. If you must shoot yourself in the foot,
376 then henceforth you will have to maintain your own local patches to strip
377 the safeties off.
378
379 8. There is a new expansion condition, bool_lax{}. Where bool{} uses the ACL
380 condition logic to determine truth/failure and will fail to expand many
381 strings, bool_lax{} uses the router condition logic, where most strings
382 do evaluate true.
383 Note: bool{00} is false, bool_lax{00} is true.
384
385 9. Routers now support multiple "condition" tests.
386
387 10. There is now a runtime configuration option "tcp_wrappers_daemon_name".
388 Setting this allows an admin to define which entry in the tcpwrappers
389 config file will be used to control access to the daemon. This option
390 is only available when Exim is built with USE_TCP_WRAPPERS. The
391 default value is set at build time using the TCP_WRAPPERS_DAEMON_NAME
392 build option.
393
394 11. [POSSIBLE CONFIG BREAKAGE] The default value for system_filter_user is now
395 the Exim run-time user, instead of root.
396
397 12. [POSSIBLE CONFIG BREAKAGE] ALT_CONFIG_ROOT_ONLY is no longer optional and
398 is forced on. This is mitigated by the new build option
399 TRUSTED_CONFIG_LIST which defines a list of configuration files which
400 are trusted; one per line. If a config file is owned by root and matches
401 a pathname in the list, then it may be invoked by the Exim build-time
402 user without Exim relinquishing root privileges.
403
404 13. [POSSIBLE CONFIG BREAKAGE] The Exim user is no longer automatically
405 trusted to supply -D<Macro[=Value]> overrides on the command-line. Going
406 forward, we recommend using TRUSTED_CONFIG_LIST with shim configs that
407 include the main config. As a transition mechanism, we are temporarily
408 providing a work-around: the new build option WHITELIST_D_MACROS provides
409 a colon-separated list of macro names which may be overridden by the Exim
410 run-time user. The values of these macros are constrained to the regex
411 ^[A-Za-z0-9_/.-]*$ (which explicitly does allow for empty values).
412
413
414 Version 4.72
415 ------------
416
417 1. TWO SECURITY FIXES: one relating to mail-spools which are globally
418 writable, the other to locking of MBX folders (not mbox).
419
420 2. MySQL stored procedures are now supported.
421
422 3. The dkim_domain transport option is now a list, not a single string, and
423 messages will be signed for each element in the list (discarding
424 duplicates).
425
426 4. The 4.70 release unexpectedly changed the behaviour of dnsdb TXT lookups
427 in the presence of multiple character strings within the RR. Prior to 4.70,
428 only the first string would be returned. The dnsdb lookup now, by default,
429 preserves the pre-4.70 semantics, but also now takes an extended output
430 separator specification. The separator can be followed by a semicolon, to
431 concatenate the individual text strings together with no join character,
432 or by a comma and a second separator character, in which case the text
433 strings within a TXT record are joined on that second character.
434 Administrators are reminded that DNS provides no ordering guarantees
435 between multiple records in an RRset. For example:
436
437 foo.example. IN TXT "a" "b" "c"
438 foo.example. IN TXT "d" "e" "f"
439
440 ${lookup dnsdb{>/ txt=foo.example}} -> "a/d"
441 ${lookup dnsdb{>/; txt=foo.example}} -> "def/abc"
442 ${lookup dnsdb{>/,+ txt=foo.example}} -> "a+b+c/d+e+f"
443
444
445 Version 4.70 / 4.71
446 -------------------
447
448 1. Native DKIM support without an external library.
449 (Note that if no action to prevent it is taken, a straight upgrade will
450 result in DKIM verification of all signed incoming emails. See spec
451 for details on conditionally disabling)
452
453 2. Experimental DCC support via dccifd (contributed by Wolfgang Breyha).
454
455 3. There is now a bool{} expansion condition which maps certain strings to
456 true/false condition values (most likely of use in conjunction with the
457 and{} expansion operator).
458
459 4. The $spam_score, $spam_bar and $spam_report variables are now available
460 at delivery time.
461
462 5. exim -bP now supports "macros", "macro_list" or "macro MACRO_NAME" as
463 options, provided that Exim is invoked by an admin_user.
464
465 6. There is a new option gnutls_compat_mode, when linked against GnuTLS,
466 which increases compatibility with older clients at the cost of decreased
467 security. Don't set this unless you need to support such clients.
468
469 7. There is a new expansion operator, ${randint:...} which will produce a
470 "random" number less than the supplied integer. This randomness is
471 not guaranteed to be cryptographically strong, but depending upon how
472 Exim was built may be better than the most naive schemes.
473
474 8. Exim now explicitly ensures that SHA256 is available when linked against
475 OpenSSL.
476
477 9. The transport_filter_timeout option now applies to SMTP transports too.
478
479
480 Version 4.69
481 ------------
482
483 1. Preliminary DKIM support in Experimental.
484
485
486 Version 4.68
487 ------------
488
489 1. The body_linecount and body_zerocount C variables are now exported in the
490 local_scan API.
491
492 2. When a dnslists lookup succeeds, the key that was looked up is now placed
493 in $dnslist_matched. When the key is an IP address, it is not reversed in
494 this variable (though it is, of course, in the actual lookup). In simple
495 cases, for example:
496
497 deny dnslists = spamhaus.example
498
499 the key is also available in another variable (in this case,
500 $sender_host_address). In more complicated cases, however, this is not
501 true. For example, using a data lookup might generate a dnslists lookup
502 like this:
503
504 deny dnslists = spamhaus.example/<|192.168.1.2|192.168.6.7|...
505
506 If this condition succeeds, the value in $dnslist_matched might be
507 192.168.6.7 (for example).
508
509 3. Authenticators now have a client_condition option. When Exim is running as
510 a client, it skips an authenticator whose client_condition expansion yields
511 "0", "no", or "false". This can be used, for example, to skip plain text
512 authenticators when the connection is not encrypted by a setting such as:
513
514 client_condition = ${if !eq{$tls_cipher}{}}
515
516 Note that the 4.67 documentation states that $tls_cipher contains the
517 cipher used for incoming messages. In fact, during SMTP delivery, it
518 contains the cipher used for the delivery. The same is true for
519 $tls_peerdn.
520
521 4. There is now a -Mvc <message-id> option, which outputs a copy of the
522 message to the standard output, in RFC 2822 format. The option can be used
523 only by an admin user.
524
525 5. There is now a /noupdate option for the ratelimit ACL condition. It
526 computes the rate and checks the limit as normal, but it does not update
527 the saved data. This means that, in relevant ACLs, it is possible to lookup
528 the existence of a specified (or auto-generated) ratelimit key without
529 incrementing the ratelimit counter for that key.
530
531 In order for this to be useful, another ACL entry must set the rate
532 for the same key somewhere (otherwise it will always be zero).
533
534 Example:
535
536 acl_check_connect:
537 # Read the rate; if it doesn't exist or is below the maximum
538 # we update it below
539 deny ratelimit = 100 / 5m / strict / noupdate
540 log_message = RATE: $sender_rate / $sender_rate_period \
541 (max $sender_rate_limit)
542
543 [... some other logic and tests...]
544
545 warn ratelimit = 100 / 5m / strict / per_cmd
546 log_message = RATE UPDATE: $sender_rate / $sender_rate_period \
547 (max $sender_rate_limit)
548 condition = ${if le{$sender_rate}{$sender_rate_limit}}
549
550 accept
551
552 6. The variable $max_received_linelength contains the number of bytes in the
553 longest line that was received as part of the message, not counting the
554 line termination character(s).
555
556 7. Host lists can now include +ignore_defer and +include_defer, analagous to
557 +ignore_unknown and +include_unknown. These options should be used with
558 care, probably only in non-critical host lists such as whitelists.
559
560 8. There's a new option called queue_only_load_latch, which defaults true.
561 If set false when queue_only_load is greater than zero, Exim re-evaluates
562 the load for each incoming message in an SMTP session. Otherwise, once one
563 message is queued, the remainder are also.
564
565 9. There is a new ACL, specified by acl_smtp_notquit, which is run in most
566 cases when an SMTP session ends without sending QUIT. However, when Exim
567 itself is is bad trouble, such as being unable to write to its log files,
568 this ACL is not run, because it might try to do things (such as write to
569 log files) that make the situation even worse.
570
571 Like the QUIT ACL, this new ACL is provided to make it possible to gather
572 statistics. Whatever it returns (accept or deny) is immaterial. The "delay"
573 modifier is forbidden in this ACL.
574
575 When the NOTQUIT ACL is running, the variable $smtp_notquit_reason is set
576 to a string that indicates the reason for the termination of the SMTP
577 connection. The possible values are:
578
579 acl-drop Another ACL issued a "drop" command
580 bad-commands Too many unknown or non-mail commands
581 command-timeout Timeout while reading SMTP commands
582 connection-lost The SMTP connection has been lost
583 data-timeout Timeout while reading message data
584 local-scan-error The local_scan() function crashed
585 local-scan-timeout The local_scan() function timed out
586 signal-exit SIGTERM or SIGINT
587 synchronization-error SMTP synchronization error
588 tls-failed TLS failed to start
589
590 In most cases when an SMTP connection is closed without having received
591 QUIT, Exim sends an SMTP response message before actually closing the
592 connection. With the exception of acl-drop, the default message can be
593 overridden by the "message" modifier in the NOTQUIT ACL. In the case of a
594 "drop" verb in another ACL, it is the message from the other ACL that is
595 used.
596
597 10. For MySQL and PostgreSQL lookups, it is now possible to specify a list of
598 servers with individual queries. This is done by starting the query with
599 "servers=x:y:z;", where each item in the list may take one of two forms:
600
601 (1) If it is just a host name, the appropriate global option (mysql_servers
602 or pgsql_servers) is searched for a host of the same name, and the
603 remaining parameters (database, user, password) are taken from there.
604
605 (2) If it contains any slashes, it is taken as a complete parameter set.
606
607 The list of servers is used in exactly the same was as the global list.
608 Once a connection to a server has happened and a query has been
609 successfully executed, processing of the lookup ceases.
610
611 This feature is intended for use in master/slave situations where updates
612 are occurring, and one wants to update a master rather than a slave. If the
613 masters are in the list for reading, you might have:
614
615 mysql_servers = slave1/db/name/pw:slave2/db/name/pw:master/db/name/pw
616
617 In an updating lookup, you could then write
618
619 ${lookup mysql{servers=master; UPDATE ...}
620
621 If, on the other hand, the master is not to be used for reading lookups:
622
623 pgsql_servers = slave1/db/name/pw:slave2/db/name/pw
624
625 you can still update the master by
626
627 ${lookup pgsql{servers=master/db/name/pw; UPDATE ...}
628
629 11. The message_body_newlines option (default FALSE, for backwards
630 compatibility) can be used to control whether newlines are present in
631 $message_body and $message_body_end. If it is FALSE, they are replaced by
632 spaces.
633
634
635 Version 4.67
636 ------------
637
638 1. There is a new log selector called smtp_no_mail, which is not included in
639 the default setting. When it is set, a line is written to the main log
640 whenever an accepted SMTP connection terminates without having issued a
641 MAIL command.
642
643 2. When an item in a dnslists list is followed by = and & and a list of IP
644 addresses, the behaviour was not clear when the lookup returned more than
645 one IP address. This has been solved by the addition of == and =& for "all"
646 rather than the default "any" matching.
647
648 3. Up till now, the only control over which cipher suites GnuTLS uses has been
649 for the cipher algorithms. New options have been added to allow some of the
650 other parameters to be varied.
651
652 4. There is a new compile-time option called ENABLE_DISABLE_FSYNC. When it is
653 set, Exim compiles a runtime option called disable_fsync.
654
655 5. There is a new variable called $smtp_count_at_connection_start.
656
657 6. There's a new control called no_pipelining.
658
659 7. There are two new variables called $sending_ip_address and $sending_port.
660 These are set whenever an SMTP connection to another host has been set up.
661
662 8. The expansion of the helo_data option in the smtp transport now happens
663 after the connection to the server has been made.
664
665 9. There is a new expansion operator ${rfc2047d: that decodes strings that
666 are encoded as per RFC 2047.
667
668 10. There is a new log selector called "pid", which causes the current process
669 id to be added to every log line, in square brackets, immediately after the
670 time and date.
671
672 11. Exim has been modified so that it flushes SMTP output before implementing
673 a delay in an ACL. It also flushes the output before performing a callout,
674 as this can take a substantial time. These behaviours can be disabled by
675 obeying control = no_delay_flush or control = no_callout_flush,
676 respectively, at some earlier stage of the connection.
677
678 12. There are two new expansion conditions that iterate over a list. They are
679 called forany and forall.
680
681 13. There's a new global option called dsn_from that can be used to vary the
682 contents of From: lines in bounces and other automatically generated
683 messages ("delivery status notifications" - hence the name of the option).
684
685 14. The smtp transport has a new option called hosts_avoid_pipelining.
686
687 15. By default, exigrep does case-insensitive matches. There is now a -I option
688 that makes it case-sensitive.
689
690 16. A number of new features ("addresses", "map", "filter", and "reduce") have
691 been added to string expansions to make it easier to process lists of
692 items, typically addresses.
693
694 17. There's a new ACL modifier called "continue". It does nothing of itself,
695 and processing of the ACL always continues with the next condition or
696 modifier. It is provided so that the side effects of expanding its argument
697 can be used.
698
699 18. It is now possible to use newline and other control characters (those with
700 values less than 32, plus DEL) as separators in lists.
701
702 19. The exigrep utility now has a -v option, which inverts the matching
703 condition.
704
705 20. The host_find_failed option in the manualroute router can now be set to
706 "ignore".
707
708
709 Version 4.66
710 ------------
711
712 No new features were added to 4.66.
713
714
715 Version 4.65
716 ------------
717
718 No new features were added to 4.65.
719
720
721 Version 4.64
722 ------------
723
724 1. ACL variables can now be given arbitrary names, as long as they start with
725 "acl_c" or "acl_m" (for connection variables and message variables), are at
726 least six characters long, with the sixth character being either a digit or
727 an underscore.
728
729 2. There is a new ACL modifier called log_reject_target. It makes it possible
730 to specify which logs are used for messages about ACL rejections.
731
732 3. There is a new authenticator called "dovecot". This is an interface to the
733 authentication facility of the Dovecot POP/IMAP server, which can support a
734 number of authentication methods.
735
736 4. The variable $message_headers_raw provides a concatenation of all the
737 messages's headers without any decoding. This is in contrast to
738 $message_headers, which does RFC2047 decoding on the header contents.
739
740 5. In a DNS black list, if two domain names, comma-separated, are given, the
741 second is used first to do an initial check, making use of any IP value
742 restrictions that are set. If there is a match, the first domain is used,
743 without any IP value restrictions, to get the TXT record.
744
745 6. All authenticators now have a server_condition option.
746
747 7. There is a new command-line option called -Mset. It is useful only in
748 conjunction with -be (that is, when testing string expansions). It must be
749 followed by a message id; Exim loads the given message from its spool
750 before doing the expansions.
751
752 8. Another similar new command-line option is called -bem. It operates like
753 -be except that it must be followed by the name of a file that contains a
754 message.
755
756 9. When an address is delayed because of a 4xx response to a RCPT command, it
757 is now the combination of sender and recipient that is delayed in
758 subsequent queue runs until its retry time is reached.
759
760 10. Unary negation and the bitwise logical operators and, or, xor, not, and
761 shift, have been added to the eval: and eval10: expansion items.
762
763 11. The variables $interface_address and $interface_port have been renamed
764 as $received_ip_address and $received_port, to make it clear that they
765 relate to message reception rather than delivery. (The old names remain
766 available for compatibility.)
767
768 12. The "message" modifier can now be used on "accept" and "discard" acl verbs
769 to vary the message that is sent when an SMTP command is accepted.
770
771
772 Version 4.63
773 ------------
774
775 1. There is a new Boolean option called filter_prepend_home for the redirect
776 router.
777
778 2. There is a new acl, set by acl_not_smtp_start, which is run right at the
779 start of receiving a non-SMTP message, before any of the message has been
780 read.
781
782 3. When an SMTP error message is specified in a "message" modifier in an ACL,
783 or in a :fail: or :defer: message in a redirect router, Exim now checks the
784 start of the message for an SMTP error code.
785
786 4. There is a new parameter for LDAP lookups called "referrals", which takes
787 one of the settings "follow" (the default) or "nofollow".
788
789 5. Version 20070721.2 of exipick now included, offering these new options:
790 --reverse
791 After all other sorting options have bee processed, reverse order
792 before displaying messages (-R is synonym).
793 --random
794 Randomize order of matching messages before displaying.
795 --size
796 Instead of displaying the matching messages, display the sum
797 of their sizes.
798 --sort <variable>[,<variable>...]
799 Before displaying matching messages, sort the messages according to
800 each messages value for each variable.
801 --not
802 Negate the value for every test (returns inverse output from the
803 same criteria without --not).
804
805
806 Version 4.62
807 ------------
808
809 1. The ${readsocket expansion item now supports Internet domain sockets as well
810 as Unix domain sockets. If the first argument begins "inet:", it must be of
811 the form "inet:host:port". The port is mandatory; it may be a number or the
812 name of a TCP port in /etc/services. The host may be a name, or it may be an
813 IP address. An ip address may optionally be enclosed in square brackets.
814 This is best for IPv6 addresses. For example:
815
816 ${readsocket{inet:[::1]:1234}{<request data>}...
817
818 Only a single host name may be given, but if looking it up yield more than
819 one IP address, they are each tried in turn until a connection is made. Once
820 a connection has been made, the behaviour is as for ${readsocket with a Unix
821 domain socket.
822
823 2. If a redirect router sets up file or pipe deliveries for more than one
824 incoming address, and the relevant transport has batch_max set greater than
825 one, a batch delivery now occurs.
826
827 3. The appendfile transport has a new option called maildirfolder_create_regex.
828 Its value is a regular expression. For a maildir delivery, this is matched
829 against the maildir directory; if it matches, Exim ensures that a
830 maildirfolder file is created alongside the new, cur, and tmp directories.
831
832
833 Version 4.61
834 ------------
835
836 The documentation is up-to-date for the 4.61 release. Major new features since
837 the 4.60 release are:
838
839 . An option called disable_ipv6, to disable the use of IPv6 completely.
840
841 . An increase in the number of ACL variables to 20 of each type.
842
843 . A change to use $auth1, $auth2, and $auth3 in authenticators instead of $1,
844 $2, $3, (though those are still set) because the numeric variables get used
845 for other things in complicated expansions.
846
847 . The default for rfc1413_query_timeout has been changed from 30s to 5s.
848
849 . It is possible to use setclassresources() on some BSD OS to control the
850 resources used in pipe deliveries.
851
852 . A new ACL modifier called add_header, which can be used with any verb.
853
854 . More errors are detectable in retry rules.
855
856 There are a number of other additions too.
857
858
859 Version 4.60
860 ------------
861
862 The documentation is up-to-date for the 4.60 release. Major new features since
863 the 4.50 release are:
864
865 . Support for SQLite.
866
867 . Support for IGNOREQUOTA in LMTP.
868
869 . Extensions to the "submission mode" features.
870
871 . Support for Client SMTP Authorization (CSA).
872
873 . Support for ratelimiting hosts and users.
874
875 . New expansion items to help with the BATV "prvs" scheme.
876
877 . A "match_ip" condition, that matches an IP address against a list.
878
879 There are many more minor changes.
880
881 ****