Add expansion variable $headers_added returning newline-sep list of headers
[exim.git] / doc / doc-txt / NewStuff
1 New Features in Exim
2 --------------------
3
4 This file contains descriptions of new features that have been added to Exim.
5 Before a formal release, there may be quite a lot of detail so that people can
6 test from the snapshots or the CVS before the documentation is updated. Once
7 the documentation is updated, this file is reduced to a short list.
8
9 Version 4.81
10 ------------
11
12 1. New command-line option -bI:sieve will list all supported sieve extensions
13 of this Exim build on standard output, one per line.
14 ManageSieve (RFC 5804) providers managing scripts for use by Exim should
15 query this to establish the correct list to include in the protocol's
16 SIEVE capability line.
17
18 2. If the -n option is combined with the -bP option, then the name of an
19 emitted option is not output, only the value (if visible to you).
20 For instance, "exim -n -bP pid_file_path" should just emit a pathname
21 followed by a newline, and no other text.
22
23 3. When built with SUPPORT_TLS and USE_GNUTLS, the SMTP transport driver now
24 has a "tls_dh_min_bits" option, to set the minimum acceptable number of
25 bits in the Diffie-Hellman prime offered by a server (in DH ciphersuites)
26 acceptable for security. (Option accepted but ignored if using OpenSSL).
27 Defaults to 1024, the old value. May be lowered only to 512, or raised as
28 far as you like. Raising this may hinder TLS interoperability with other
29 sites and is not currently recommended. Lowering this will permit you to
30 establish a TLS session which is not as secure as you might like.
31
32 Unless you really know what you are doing, leave it alone.
33
34 4. If not built with DISABLE_DNSSEC, Exim now has the main option
35 dns_use_dnssec; if set to 1 then Exim will initialise the resolver library
36 to send the DO flag to your recursive resolver. If you have a recursive
37 resolver, which can set the Authenticated Data (AD) flag in results, Exim
38 can now detect this.
39
40 Current status: work-in-progress; $sender_host_dnssec variable added.
41
42 5. DSCP support for outbound connections: on a transport using the smtp driver,
43 set "dscp = ef", for instance, to cause the connections to have the relevant
44 DSCP (IPv4 TOS or IPv6 TCLASS) value in the header.
45
46 Similarly for inbound connections, there is a new control modifier, dscp,
47 so "warn control = dscp/ef" in the connect ACL, or after authentication.
48
49 Supported values depend upon system libraries. "exim -bI:dscp" to list the
50 ones Exim knows of. You can also set a raw number 0..0x3F.
51
52 6. The -G command-line flag is no longer ignored; it is now equivalent to an
53 ACL setting "control = suppress_local_fixups". The -L command-line flag
54 is now accepted and forces use of syslog, with the provided tag as the
55 process name. A few other flags used by Sendmail are now accepted and
56 ignored.
57
58 7. New cutthrough routing feature. Requested by a "control = cutthrough_delivery"
59 ACL modifier; works for single-recipient mails which are recieved on and
60 deliverable via SMTP. Using the connection made for a recipient verify,
61 if requested before the verify, or a new one made for the purpose while
62 the inbound connection is still active. The bulk of the mail item is copied
63 direct from the inbound socket to the outbound (as well as the spool file).
64 When the source notifies the end of data, the data acceptance by the destination
65 is negociated before the acceptance is sent to the source. If the destination
66 does not accept the mail item, for example due to content-scanning, the item
67 is not accepted from the source and therefore there is no need to generate
68 a bounce mail. This is of benefit when providing a secondary-MX service.
69 The downside is that delays are under the control of the ultimate destination
70 system not your own.
71
72 The Recieved-by: header on items delivered by cutthrough is generated
73 early in reception rather than at the end; this will affect any timestamp
74 included. The log line showing delivery is recorded before that showing
75 reception; it uses a new ">>" tag instead of "=>".
76
77 To support the feature, verify-callout connections can now use ESMTP and TLS.
78 The usual smtp transport options are honoured, plus a (new, default everything)
79 hosts_verify_avoid_tls.
80
81 New variable families named tls_in_cipher, tls_out_cipher etc. are introduced
82 for specific access to the information for each connection. The old names
83 are present for now but deprecated.
84
85 Not yet supported: IGNOREQUOTA, SIZE, PIPELINING, AUTH.
86
87 8. New expansion operators ${listnamed:name} to get the content of a named list
88 and ${listcount:string} to count the items in a list.
89
90 9. New global option "gnutls_enable_pkcs11", defaults false. The GnuTLS
91 rewrite in 4.80 combines with GnuTLS 2.12.0 or later, to autoload PKCS11
92 modules. For some situations this is desirable, but we expect admin in
93 those situations to know they want the feature. More commonly, it means
94 that GUI user modules get loaded and are broken by the setuid Exim being
95 unable to access files specified in environment variables and passed
96 through, thus breakage. So we explicitly inhibit the PKCS11 initialisation
97 unless this new option is set.
98
99 10. The "acl = name" condition on an ACL now supports optional arguments.
100 New expansion item "${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
122 Version 4.80
123 ------------
124
125 1. New authenticator driver, "gsasl". Server-only (at present).
126 This is a SASL interface, licensed under GPL, which can be found at
127 http://www.gnu.org/software/gsasl/.
128 This system does not provide sources of data for authentication, so
129 careful use needs to be made of the conditions in Exim.
130
131 2. New authenticator driver, "heimdal_gssapi". Server-only.
132 A replacement for using cyrus_sasl with Heimdal, now that $KRB5_KTNAME
133 is no longer honoured for setuid programs by Heimdal. Use the
134 "server_keytab" option to point to the keytab.
135
136 3. The "pkg-config" system can now be used when building Exim to reference
137 cflags and library information for lookups and authenticators, rather
138 than having to update "CFLAGS", "AUTH_LIBS", "LOOKUP_INCLUDE" and
139 "LOOKUP_LIBS" directly. Similarly for handling the TLS library support
140 without adjusting "TLS_INCLUDE" and "TLS_LIBS".
141
142 In addition, setting PCRE_CONFIG=yes will query the pcre-config tool to
143 find the headers and libraries for PCRE.
144
145 4. New expansion variable $tls_bits.
146
147 5. New lookup type, "dbmjz". Key is an Exim list, the elements of which will
148 be joined together with ASCII NUL characters to construct the key to pass
149 into the DBM library. Can be used with gsasl to access sasldb2 files as
150 used by Cyrus SASL.
151
152 6. OpenSSL now supports TLS1.1 and TLS1.2 with OpenSSL 1.0.1.
153
154 Avoid release 1.0.1a if you can. Note that the default value of
155 "openssl_options" is no longer "+dont_insert_empty_fragments", as that
156 increased susceptibility to attack. This may still have interoperability
157 implications for very old clients (see version 4.31 change 37) but
158 administrators can choose to make the trade-off themselves and restore
159 compatibility at the cost of session security.
160
161 7. Use of the new expansion variable $tls_sni in the main configuration option
162 tls_certificate will cause Exim to re-expand the option, if the client
163 sends the TLS Server Name Indication extension, to permit choosing a
164 different certificate; tls_privatekey will also be re-expanded. You must
165 still set these options to expand to valid files when $tls_sni is not set.
166
167 The SMTP Transport has gained the option tls_sni, which will set a hostname
168 for outbound TLS sessions, and set $tls_sni too.
169
170 A new log_selector, +tls_sni, has been added, to log received SNI values
171 for Exim as a server.
172
173 8. The existing "accept_8bitmime" option now defaults to true. This means
174 that Exim is deliberately not strictly RFC compliant. We're following
175 Dan Bernstein's advice in http://cr.yp.to/smtp/8bitmime.html by default.
176 Those who disagree, or know that they are talking to mail servers that,
177 even today, are not 8-bit clean, need to turn off this option.
178
179 9. Exim can now be started with -bw (with an optional timeout, given as
180 -bw<timespec>). With this, stdin at startup is a socket that is
181 already listening for connections. This has a more modern name of
182 "socket activation", but forcing the activated socket to fd 0. We're
183 interested in adding more support for modern variants.
184
185 10. ${eval } now uses 64-bit values on supporting platforms. A new "G" suffix
186 for numbers indicates multiplication by 1024^3.
187
188 11. The GnuTLS support has been revamped; the three options gnutls_require_kx,
189 gnutls_require_mac & gnutls_require_protocols are no longer supported.
190 tls_require_ciphers is now parsed by gnutls_priority_init(3) as a priority
191 string, documentation for which is at:
192 http://www.gnu.org/software/gnutls/manual/html_node/Priority-Strings.html
193
194 SNI support has been added to Exim's GnuTLS integration too.
195
196 For sufficiently recent GnuTLS libraries, ${randint:..} will now use
197 gnutls_rnd(), asking for GNUTLS_RND_NONCE level randomness.
198
199 12. With OpenSSL, if built with EXPERIMENTAL_OCSP, a new option tls_ocsp_file
200 is now available. If the contents of the file are valid, then Exim will
201 send that back in response to a TLS status request; this is OCSP Stapling.
202 Exim will not maintain the contents of the file in any way: administrators
203 are responsible for ensuring that it is up-to-date.
204
205 See "experimental-spec.txt" for more details.
206
207 13. ${lookup dnsdb{ }} supports now SPF record types. They are handled
208 identically to TXT record lookups.
209
210 14. New expansion variable $tod_epoch_l for higher-precision time.
211
212 15. New global option tls_dh_max_bits, defaulting to current value of NSS
213 hard-coded limit of DH ephemeral bits, to fix interop problems caused by
214 GnuTLS 2.12 library recommending a bit count higher than NSS supports.
215
216 16. tls_dhparam now used by both OpenSSL and GnuTLS, can be path or identifier.
217 Option can now be a path or an identifier for a standard prime.
218 If unset, we use the DH prime from section 2.2 of RFC 5114, "ike23".
219 Set to "historic" to get the old GnuTLS behaviour of auto-generated DH
220 primes.
221
222 17. SSLv2 now disabled by default in OpenSSL. (Never supported by GnuTLS).
223 Use "openssl_options -no_sslv2" to re-enable support, if your OpenSSL
224 install was not built with OPENSSL_NO_SSL2 ("no-ssl2").
225
226
227 Version 4.77
228 ------------
229
230 1. New options for the ratelimit ACL condition: /count= and /unique=.
231 The /noupdate option has been replaced by a /readonly option.
232
233 2. The SMTP transport's protocol option may now be set to "smtps", to
234 use SSL-on-connect outbound.
235
236 3. New variable $av_failed, set true if the AV scanner deferred; ie, when
237 there is a problem talking to the AV scanner, or the AV scanner running.
238
239 4. New expansion conditions, "inlist" and "inlisti", which take simple lists
240 and check if the search item is a member of the list. This does not
241 support named lists, but does subject the list part to string expansion.
242
243 5. Unless the new EXPAND_LISTMATCH_RHS build option is set when Exim was
244 built, Exim no longer performs string expansion on the second string of
245 the match_* expansion conditions: "match_address", "match_domain",
246 "match_ip" & "match_local_part". Named lists can still be used.
247
248
249 Version 4.76
250 ------------
251
252 1. The global option "dns_use_edns0" may be set to coerce EDNS0 usage on
253 or off in the resolver library.
254
255
256 Version 4.75
257 ------------
258
259 1. In addition to the existing LDAP and LDAP/SSL ("ldaps") support, there
260 is now LDAP/TLS support, given sufficiently modern OpenLDAP client
261 libraries. The following global options have been added in support of
262 this: ldap_ca_cert_dir, ldap_ca_cert_file, ldap_cert_file, ldap_cert_key,
263 ldap_cipher_suite, ldap_require_cert, ldap_start_tls.
264
265 2. The pipe transport now takes a boolean option, "freeze_signal", default
266 false. When true, if the external delivery command exits on a signal then
267 Exim will freeze the message in the queue, instead of generating a bounce.
268
269 3. Log filenames may now use %M as an escape, instead of %D (still available).
270 The %M pattern expands to yyyymm, providing month-level resolution.
271
272 4. The $message_linecount variable is now updated for the maildir_tag option,
273 in the same way as $message_size, to reflect the real number of lines,
274 including any header additions or removals from transport.
275
276 5. When contacting a pool of SpamAssassin servers configured in spamd_address,
277 Exim now selects entries randomly, to better scale in a cluster setup.
278
279
280 Version 4.74
281 ------------
282
283 1. SECURITY FIX: privilege escalation flaw fixed. On Linux (and only Linux)
284 the flaw permitted the Exim run-time user to cause root to append to
285 arbitrary files of the attacker's choosing, with the content based
286 on content supplied by the attacker.
287
288 2. Exim now supports loading some lookup types at run-time, using your
289 platform's dlopen() functionality. This has limited platform support
290 and the intention is not to support every variant, it's limited to
291 dlopen(). This permits the main Exim binary to not be linked against
292 all the libraries needed for all the lookup types.
293
294
295 Version 4.73
296 ------------
297
298 NOTE: this version is not guaranteed backwards-compatible, please read the
299 items below carefully
300
301 1. A new main configuration option, "openssl_options", is available if Exim
302 is built with SSL support provided by OpenSSL. The option allows
303 administrators to specify OpenSSL options to be used on connections;
304 typically this is to set bug compatibility features which the OpenSSL
305 developers have not enabled by default. There may be security
306 consequences for certain options, so these should not be changed
307 frivolously.
308
309 2. A new pipe transport option, "permit_coredumps", may help with problem
310 diagnosis in some scenarios. Note that Exim is typically installed as
311 a setuid binary, which on most OSes will inhibit coredumps by default,
312 so that safety mechanism would have to be overridden for this option to
313 be able to take effect.
314
315 3. ClamAV 0.95 is now required for ClamAV support in Exim, unless
316 Local/Makefile sets: WITH_OLD_CLAMAV_STREAM=yes
317 Note that this switches Exim to use a new API ("INSTREAM") and a future
318 release of ClamAV will remove support for the old API ("STREAM").
319
320 The av_scanner option, when set to "clamd", now takes an optional third
321 part, "local", which causes Exim to pass a filename to ClamAV instead of
322 the file content. This is the same behaviour as when clamd is pointed at
323 a Unix-domain socket. For example:
324
325 av_scanner = clamd:192.0.2.3 1234:local
326
327 ClamAV's ExtendedDetectionInfo response format is now handled.
328
329 4. There is now a -bmalware option, restricted to admin users. This option
330 takes one parameter, a filename, and scans that file with Exim's
331 malware-scanning framework. This is intended purely as a debugging aid
332 to ensure that Exim's scanning is working, not to replace other tools.
333 Note that the ACL framework is not invoked, so if av_scanner references
334 ACL variables without a fallback then this will fail.
335
336 5. There is a new expansion operator, "reverse_ip", which will reverse IP
337 addresses; IPv4 into dotted quad, IPv6 into dotted nibble. Examples:
338
339 ${reverse_ip:192.0.2.4}
340 -> 4.2.0.192
341 ${reverse_ip:2001:0db8:c42:9:1:abcd:192.0.2.3}
342 -> 3.0.2.0.0.0.0.c.d.c.b.a.1.0.0.0.9.0.0.0.2.4.c.0.8.b.d.0.1.0.0.2
343
344 6. There is a new ACL control called "debug", to enable debug logging.
345 This allows selective logging of certain incoming transactions within
346 production environments, with some care. It takes two options, "tag"
347 and "opts"; "tag" is included in the filename of the log and "opts"
348 is used as per the -d<options> command-line option. Examples, which
349 don't all make sense in all contexts:
350
351 control = debug
352 control = debug/tag=.$sender_host_address
353 control = debug/opts=+expand+acl
354 control = debug/tag=.$message_exim_id/opts=+expand
355
356 7. It has always been implicit in the design and the documentation that
357 "the Exim user" is not root. src/EDITME said that using root was
358 "very strongly discouraged". This is not enough to keep people from
359 shooting themselves in the foot in days when many don't configure Exim
360 themselves but via package build managers. The security consequences of
361 running various bits of network code are severe if there should be bugs in
362 them. As such, the Exim user may no longer be root. If configured
363 statically, Exim will refuse to build. If configured as ref:user then Exim
364 will exit shortly after start-up. If you must shoot yourself in the foot,
365 then henceforth you will have to maintain your own local patches to strip
366 the safeties off.
367
368 8. There is a new expansion condition, bool_lax{}. Where bool{} uses the ACL
369 condition logic to determine truth/failure and will fail to expand many
370 strings, bool_lax{} uses the router condition logic, where most strings
371 do evaluate true.
372 Note: bool{00} is false, bool_lax{00} is true.
373
374 9. Routers now support multiple "condition" tests.
375
376 10. There is now a runtime configuration option "tcp_wrappers_daemon_name".
377 Setting this allows an admin to define which entry in the tcpwrappers
378 config file will be used to control access to the daemon. This option
379 is only available when Exim is built with USE_TCP_WRAPPERS. The
380 default value is set at build time using the TCP_WRAPPERS_DAEMON_NAME
381 build option.
382
383 11. [POSSIBLE CONFIG BREAKAGE] The default value for system_filter_user is now
384 the Exim run-time user, instead of root.
385
386 12. [POSSIBLE CONFIG BREAKAGE] ALT_CONFIG_ROOT_ONLY is no longer optional and
387 is forced on. This is mitigated by the new build option
388 TRUSTED_CONFIG_LIST which defines a list of configuration files which
389 are trusted; one per line. If a config file is owned by root and matches
390 a pathname in the list, then it may be invoked by the Exim build-time
391 user without Exim relinquishing root privileges.
392
393 13. [POSSIBLE CONFIG BREAKAGE] The Exim user is no longer automatically
394 trusted to supply -D<Macro[=Value]> overrides on the command-line. Going
395 forward, we recommend using TRUSTED_CONFIG_LIST with shim configs that
396 include the main config. As a transition mechanism, we are temporarily
397 providing a work-around: the new build option WHITELIST_D_MACROS provides
398 a colon-separated list of macro names which may be overridden by the Exim
399 run-time user. The values of these macros are constrained to the regex
400 ^[A-Za-z0-9_/.-]*$ (which explicitly does allow for empty values).
401
402
403 Version 4.72
404 ------------
405
406 1. TWO SECURITY FIXES: one relating to mail-spools which are globally
407 writable, the other to locking of MBX folders (not mbox).
408
409 2. MySQL stored procedures are now supported.
410
411 3. The dkim_domain transport option is now a list, not a single string, and
412 messages will be signed for each element in the list (discarding
413 duplicates).
414
415 4. The 4.70 release unexpectedly changed the behaviour of dnsdb TXT lookups
416 in the presence of multiple character strings within the RR. Prior to 4.70,
417 only the first string would be returned. The dnsdb lookup now, by default,
418 preserves the pre-4.70 semantics, but also now takes an extended output
419 separator specification. The separator can be followed by a semicolon, to
420 concatenate the individual text strings together with no join character,
421 or by a comma and a second separator character, in which case the text
422 strings within a TXT record are joined on that second character.
423 Administrators are reminded that DNS provides no ordering guarantees
424 between multiple records in an RRset. For example:
425
426 foo.example. IN TXT "a" "b" "c"
427 foo.example. IN TXT "d" "e" "f"
428
429 ${lookup dnsdb{>/ txt=foo.example}} -> "a/d"
430 ${lookup dnsdb{>/; txt=foo.example}} -> "def/abc"
431 ${lookup dnsdb{>/,+ txt=foo.example}} -> "a+b+c/d+e+f"
432
433
434 Version 4.70 / 4.71
435 -------------------
436
437 1. Native DKIM support without an external library.
438 (Note that if no action to prevent it is taken, a straight upgrade will
439 result in DKIM verification of all signed incoming emails. See spec
440 for details on conditionally disabling)
441
442 2. Experimental DCC support via dccifd (contributed by Wolfgang Breyha).
443
444 3. There is now a bool{} expansion condition which maps certain strings to
445 true/false condition values (most likely of use in conjunction with the
446 and{} expansion operator).
447
448 4. The $spam_score, $spam_bar and $spam_report variables are now available
449 at delivery time.
450
451 5. exim -bP now supports "macros", "macro_list" or "macro MACRO_NAME" as
452 options, provided that Exim is invoked by an admin_user.
453
454 6. There is a new option gnutls_compat_mode, when linked against GnuTLS,
455 which increases compatibility with older clients at the cost of decreased
456 security. Don't set this unless you need to support such clients.
457
458 7. There is a new expansion operator, ${randint:...} which will produce a
459 "random" number less than the supplied integer. This randomness is
460 not guaranteed to be cryptographically strong, but depending upon how
461 Exim was built may be better than the most naive schemes.
462
463 8. Exim now explicitly ensures that SHA256 is available when linked against
464 OpenSSL.
465
466 9. The transport_filter_timeout option now applies to SMTP transports too.
467
468
469 Version 4.69
470 ------------
471
472 1. Preliminary DKIM support in Experimental.
473
474
475 Version 4.68
476 ------------
477
478 1. The body_linecount and body_zerocount C variables are now exported in the
479 local_scan API.
480
481 2. When a dnslists lookup succeeds, the key that was looked up is now placed
482 in $dnslist_matched. When the key is an IP address, it is not reversed in
483 this variable (though it is, of course, in the actual lookup). In simple
484 cases, for example:
485
486 deny dnslists = spamhaus.example
487
488 the key is also available in another variable (in this case,
489 $sender_host_address). In more complicated cases, however, this is not
490 true. For example, using a data lookup might generate a dnslists lookup
491 like this:
492
493 deny dnslists = spamhaus.example/<|192.168.1.2|192.168.6.7|...
494
495 If this condition succeeds, the value in $dnslist_matched might be
496 192.168.6.7 (for example).
497
498 3. Authenticators now have a client_condition option. When Exim is running as
499 a client, it skips an authenticator whose client_condition expansion yields
500 "0", "no", or "false". This can be used, for example, to skip plain text
501 authenticators when the connection is not encrypted by a setting such as:
502
503 client_condition = ${if !eq{$tls_cipher}{}}
504
505 Note that the 4.67 documentation states that $tls_cipher contains the
506 cipher used for incoming messages. In fact, during SMTP delivery, it
507 contains the cipher used for the delivery. The same is true for
508 $tls_peerdn.
509
510 4. There is now a -Mvc <message-id> option, which outputs a copy of the
511 message to the standard output, in RFC 2822 format. The option can be used
512 only by an admin user.
513
514 5. There is now a /noupdate option for the ratelimit ACL condition. It
515 computes the rate and checks the limit as normal, but it does not update
516 the saved data. This means that, in relevant ACLs, it is possible to lookup
517 the existence of a specified (or auto-generated) ratelimit key without
518 incrementing the ratelimit counter for that key.
519
520 In order for this to be useful, another ACL entry must set the rate
521 for the same key somewhere (otherwise it will always be zero).
522
523 Example:
524
525 acl_check_connect:
526 # Read the rate; if it doesn't exist or is below the maximum
527 # we update it below
528 deny ratelimit = 100 / 5m / strict / noupdate
529 log_message = RATE: $sender_rate / $sender_rate_period \
530 (max $sender_rate_limit)
531
532 [... some other logic and tests...]
533
534 warn ratelimit = 100 / 5m / strict / per_cmd
535 log_message = RATE UPDATE: $sender_rate / $sender_rate_period \
536 (max $sender_rate_limit)
537 condition = ${if le{$sender_rate}{$sender_rate_limit}}
538
539 accept
540
541 6. The variable $max_received_linelength contains the number of bytes in the
542 longest line that was received as part of the message, not counting the
543 line termination character(s).
544
545 7. Host lists can now include +ignore_defer and +include_defer, analagous to
546 +ignore_unknown and +include_unknown. These options should be used with
547 care, probably only in non-critical host lists such as whitelists.
548
549 8. There's a new option called queue_only_load_latch, which defaults true.
550 If set false when queue_only_load is greater than zero, Exim re-evaluates
551 the load for each incoming message in an SMTP session. Otherwise, once one
552 message is queued, the remainder are also.
553
554 9. There is a new ACL, specified by acl_smtp_notquit, which is run in most
555 cases when an SMTP session ends without sending QUIT. However, when Exim
556 itself is is bad trouble, such as being unable to write to its log files,
557 this ACL is not run, because it might try to do things (such as write to
558 log files) that make the situation even worse.
559
560 Like the QUIT ACL, this new ACL is provided to make it possible to gather
561 statistics. Whatever it returns (accept or deny) is immaterial. The "delay"
562 modifier is forbidden in this ACL.
563
564 When the NOTQUIT ACL is running, the variable $smtp_notquit_reason is set
565 to a string that indicates the reason for the termination of the SMTP
566 connection. The possible values are:
567
568 acl-drop Another ACL issued a "drop" command
569 bad-commands Too many unknown or non-mail commands
570 command-timeout Timeout while reading SMTP commands
571 connection-lost The SMTP connection has been lost
572 data-timeout Timeout while reading message data
573 local-scan-error The local_scan() function crashed
574 local-scan-timeout The local_scan() function timed out
575 signal-exit SIGTERM or SIGINT
576 synchronization-error SMTP synchronization error
577 tls-failed TLS failed to start
578
579 In most cases when an SMTP connection is closed without having received
580 QUIT, Exim sends an SMTP response message before actually closing the
581 connection. With the exception of acl-drop, the default message can be
582 overridden by the "message" modifier in the NOTQUIT ACL. In the case of a
583 "drop" verb in another ACL, it is the message from the other ACL that is
584 used.
585
586 10. For MySQL and PostgreSQL lookups, it is now possible to specify a list of
587 servers with individual queries. This is done by starting the query with
588 "servers=x:y:z;", where each item in the list may take one of two forms:
589
590 (1) If it is just a host name, the appropriate global option (mysql_servers
591 or pgsql_servers) is searched for a host of the same name, and the
592 remaining parameters (database, user, password) are taken from there.
593
594 (2) If it contains any slashes, it is taken as a complete parameter set.
595
596 The list of servers is used in exactly the same was as the global list.
597 Once a connection to a server has happened and a query has been
598 successfully executed, processing of the lookup ceases.
599
600 This feature is intended for use in master/slave situations where updates
601 are occurring, and one wants to update a master rather than a slave. If the
602 masters are in the list for reading, you might have:
603
604 mysql_servers = slave1/db/name/pw:slave2/db/name/pw:master/db/name/pw
605
606 In an updating lookup, you could then write
607
608 ${lookup mysql{servers=master; UPDATE ...}
609
610 If, on the other hand, the master is not to be used for reading lookups:
611
612 pgsql_servers = slave1/db/name/pw:slave2/db/name/pw
613
614 you can still update the master by
615
616 ${lookup pgsql{servers=master/db/name/pw; UPDATE ...}
617
618 11. The message_body_newlines option (default FALSE, for backwards
619 compatibility) can be used to control whether newlines are present in
620 $message_body and $message_body_end. If it is FALSE, they are replaced by
621 spaces.
622
623
624 Version 4.67
625 ------------
626
627 1. There is a new log selector called smtp_no_mail, which is not included in
628 the default setting. When it is set, a line is written to the main log
629 whenever an accepted SMTP connection terminates without having issued a
630 MAIL command.
631
632 2. When an item in a dnslists list is followed by = and & and a list of IP
633 addresses, the behaviour was not clear when the lookup returned more than
634 one IP address. This has been solved by the addition of == and =& for "all"
635 rather than the default "any" matching.
636
637 3. Up till now, the only control over which cipher suites GnuTLS uses has been
638 for the cipher algorithms. New options have been added to allow some of the
639 other parameters to be varied.
640
641 4. There is a new compile-time option called ENABLE_DISABLE_FSYNC. When it is
642 set, Exim compiles a runtime option called disable_fsync.
643
644 5. There is a new variable called $smtp_count_at_connection_start.
645
646 6. There's a new control called no_pipelining.
647
648 7. There are two new variables called $sending_ip_address and $sending_port.
649 These are set whenever an SMTP connection to another host has been set up.
650
651 8. The expansion of the helo_data option in the smtp transport now happens
652 after the connection to the server has been made.
653
654 9. There is a new expansion operator ${rfc2047d: that decodes strings that
655 are encoded as per RFC 2047.
656
657 10. There is a new log selector called "pid", which causes the current process
658 id to be added to every log line, in square brackets, immediately after the
659 time and date.
660
661 11. Exim has been modified so that it flushes SMTP output before implementing
662 a delay in an ACL. It also flushes the output before performing a callout,
663 as this can take a substantial time. These behaviours can be disabled by
664 obeying control = no_delay_flush or control = no_callout_flush,
665 respectively, at some earlier stage of the connection.
666
667 12. There are two new expansion conditions that iterate over a list. They are
668 called forany and forall.
669
670 13. There's a new global option called dsn_from that can be used to vary the
671 contents of From: lines in bounces and other automatically generated
672 messages ("delivery status notifications" - hence the name of the option).
673
674 14. The smtp transport has a new option called hosts_avoid_pipelining.
675
676 15. By default, exigrep does case-insensitive matches. There is now a -I option
677 that makes it case-sensitive.
678
679 16. A number of new features ("addresses", "map", "filter", and "reduce") have
680 been added to string expansions to make it easier to process lists of
681 items, typically addresses.
682
683 17. There's a new ACL modifier called "continue". It does nothing of itself,
684 and processing of the ACL always continues with the next condition or
685 modifier. It is provided so that the side effects of expanding its argument
686 can be used.
687
688 18. It is now possible to use newline and other control characters (those with
689 values less than 32, plus DEL) as separators in lists.
690
691 19. The exigrep utility now has a -v option, which inverts the matching
692 condition.
693
694 20. The host_find_failed option in the manualroute router can now be set to
695 "ignore".
696
697
698 Version 4.66
699 ------------
700
701 No new features were added to 4.66.
702
703
704 Version 4.65
705 ------------
706
707 No new features were added to 4.65.
708
709
710 Version 4.64
711 ------------
712
713 1. ACL variables can now be given arbitrary names, as long as they start with
714 "acl_c" or "acl_m" (for connection variables and message variables), are at
715 least six characters long, with the sixth character being either a digit or
716 an underscore.
717
718 2. There is a new ACL modifier called log_reject_target. It makes it possible
719 to specify which logs are used for messages about ACL rejections.
720
721 3. There is a new authenticator called "dovecot". This is an interface to the
722 authentication facility of the Dovecot POP/IMAP server, which can support a
723 number of authentication methods.
724
725 4. The variable $message_headers_raw provides a concatenation of all the
726 messages's headers without any decoding. This is in contrast to
727 $message_headers, which does RFC2047 decoding on the header contents.
728
729 5. In a DNS black list, if two domain names, comma-separated, are given, the
730 second is used first to do an initial check, making use of any IP value
731 restrictions that are set. If there is a match, the first domain is used,
732 without any IP value restrictions, to get the TXT record.
733
734 6. All authenticators now have a server_condition option.
735
736 7. There is a new command-line option called -Mset. It is useful only in
737 conjunction with -be (that is, when testing string expansions). It must be
738 followed by a message id; Exim loads the given message from its spool
739 before doing the expansions.
740
741 8. Another similar new command-line option is called -bem. It operates like
742 -be except that it must be followed by the name of a file that contains a
743 message.
744
745 9. When an address is delayed because of a 4xx response to a RCPT command, it
746 is now the combination of sender and recipient that is delayed in
747 subsequent queue runs until its retry time is reached.
748
749 10. Unary negation and the bitwise logical operators and, or, xor, not, and
750 shift, have been added to the eval: and eval10: expansion items.
751
752 11. The variables $interface_address and $interface_port have been renamed
753 as $received_ip_address and $received_port, to make it clear that they
754 relate to message reception rather than delivery. (The old names remain
755 available for compatibility.)
756
757 12. The "message" modifier can now be used on "accept" and "discard" acl verbs
758 to vary the message that is sent when an SMTP command is accepted.
759
760
761 Version 4.63
762 ------------
763
764 1. There is a new Boolean option called filter_prepend_home for the redirect
765 router.
766
767 2. There is a new acl, set by acl_not_smtp_start, which is run right at the
768 start of receiving a non-SMTP message, before any of the message has been
769 read.
770
771 3. When an SMTP error message is specified in a "message" modifier in an ACL,
772 or in a :fail: or :defer: message in a redirect router, Exim now checks the
773 start of the message for an SMTP error code.
774
775 4. There is a new parameter for LDAP lookups called "referrals", which takes
776 one of the settings "follow" (the default) or "nofollow".
777
778 5. Version 20070721.2 of exipick now included, offering these new options:
779 --reverse
780 After all other sorting options have bee processed, reverse order
781 before displaying messages (-R is synonym).
782 --random
783 Randomize order of matching messages before displaying.
784 --size
785 Instead of displaying the matching messages, display the sum
786 of their sizes.
787 --sort <variable>[,<variable>...]
788 Before displaying matching messages, sort the messages according to
789 each messages value for each variable.
790 --not
791 Negate the value for every test (returns inverse output from the
792 same criteria without --not).
793
794
795 Version 4.62
796 ------------
797
798 1. The ${readsocket expansion item now supports Internet domain sockets as well
799 as Unix domain sockets. If the first argument begins "inet:", it must be of
800 the form "inet:host:port". The port is mandatory; it may be a number or the
801 name of a TCP port in /etc/services. The host may be a name, or it may be an
802 IP address. An ip address may optionally be enclosed in square brackets.
803 This is best for IPv6 addresses. For example:
804
805 ${readsocket{inet:[::1]:1234}{<request data>}...
806
807 Only a single host name may be given, but if looking it up yield more than
808 one IP address, they are each tried in turn until a connection is made. Once
809 a connection has been made, the behaviour is as for ${readsocket with a Unix
810 domain socket.
811
812 2. If a redirect router sets up file or pipe deliveries for more than one
813 incoming address, and the relevant transport has batch_max set greater than
814 one, a batch delivery now occurs.
815
816 3. The appendfile transport has a new option called maildirfolder_create_regex.
817 Its value is a regular expression. For a maildir delivery, this is matched
818 against the maildir directory; if it matches, Exim ensures that a
819 maildirfolder file is created alongside the new, cur, and tmp directories.
820
821
822 Version 4.61
823 ------------
824
825 The documentation is up-to-date for the 4.61 release. Major new features since
826 the 4.60 release are:
827
828 . An option called disable_ipv6, to disable the use of IPv6 completely.
829
830 . An increase in the number of ACL variables to 20 of each type.
831
832 . A change to use $auth1, $auth2, and $auth3 in authenticators instead of $1,
833 $2, $3, (though those are still set) because the numeric variables get used
834 for other things in complicated expansions.
835
836 . The default for rfc1413_query_timeout has been changed from 30s to 5s.
837
838 . It is possible to use setclassresources() on some BSD OS to control the
839 resources used in pipe deliveries.
840
841 . A new ACL modifier called add_header, which can be used with any verb.
842
843 . More errors are detectable in retry rules.
844
845 There are a number of other additions too.
846
847
848 Version 4.60
849 ------------
850
851 The documentation is up-to-date for the 4.60 release. Major new features since
852 the 4.50 release are:
853
854 . Support for SQLite.
855
856 . Support for IGNOREQUOTA in LMTP.
857
858 . Extensions to the "submission mode" features.
859
860 . Support for Client SMTP Authorization (CSA).
861
862 . Support for ratelimiting hosts and users.
863
864 . New expansion items to help with the BATV "prvs" scheme.
865
866 . A "match_ip" condition, that matches an IP address against a list.
867
868 There are many more minor changes.
869
870 ****