ccf2dc63a94c463182c1bd823788a9a23b200104
[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
119 Version 4.80
120 ------------
121
122 1. New authenticator driver, "gsasl". Server-only (at present).
123 This is a SASL interface, licensed under GPL, which can be found at
124 http://www.gnu.org/software/gsasl/.
125 This system does not provide sources of data for authentication, so
126 careful use needs to be made of the conditions in Exim.
127
128 2. New authenticator driver, "heimdal_gssapi". Server-only.
129 A replacement for using cyrus_sasl with Heimdal, now that $KRB5_KTNAME
130 is no longer honoured for setuid programs by Heimdal. Use the
131 "server_keytab" option to point to the keytab.
132
133 3. The "pkg-config" system can now be used when building Exim to reference
134 cflags and library information for lookups and authenticators, rather
135 than having to update "CFLAGS", "AUTH_LIBS", "LOOKUP_INCLUDE" and
136 "LOOKUP_LIBS" directly. Similarly for handling the TLS library support
137 without adjusting "TLS_INCLUDE" and "TLS_LIBS".
138
139 In addition, setting PCRE_CONFIG=yes will query the pcre-config tool to
140 find the headers and libraries for PCRE.
141
142 4. New expansion variable $tls_bits.
143
144 5. New lookup type, "dbmjz". Key is an Exim list, the elements of which will
145 be joined together with ASCII NUL characters to construct the key to pass
146 into the DBM library. Can be used with gsasl to access sasldb2 files as
147 used by Cyrus SASL.
148
149 6. OpenSSL now supports TLS1.1 and TLS1.2 with OpenSSL 1.0.1.
150
151 Avoid release 1.0.1a if you can. Note that the default value of
152 "openssl_options" is no longer "+dont_insert_empty_fragments", as that
153 increased susceptibility to attack. This may still have interoperability
154 implications for very old clients (see version 4.31 change 37) but
155 administrators can choose to make the trade-off themselves and restore
156 compatibility at the cost of session security.
157
158 7. Use of the new expansion variable $tls_sni in the main configuration option
159 tls_certificate will cause Exim to re-expand the option, if the client
160 sends the TLS Server Name Indication extension, to permit choosing a
161 different certificate; tls_privatekey will also be re-expanded. You must
162 still set these options to expand to valid files when $tls_sni is not set.
163
164 The SMTP Transport has gained the option tls_sni, which will set a hostname
165 for outbound TLS sessions, and set $tls_sni too.
166
167 A new log_selector, +tls_sni, has been added, to log received SNI values
168 for Exim as a server.
169
170 8. The existing "accept_8bitmime" option now defaults to true. This means
171 that Exim is deliberately not strictly RFC compliant. We're following
172 Dan Bernstein's advice in http://cr.yp.to/smtp/8bitmime.html by default.
173 Those who disagree, or know that they are talking to mail servers that,
174 even today, are not 8-bit clean, need to turn off this option.
175
176 9. Exim can now be started with -bw (with an optional timeout, given as
177 -bw<timespec>). With this, stdin at startup is a socket that is
178 already listening for connections. This has a more modern name of
179 "socket activation", but forcing the activated socket to fd 0. We're
180 interested in adding more support for modern variants.
181
182 10. ${eval } now uses 64-bit values on supporting platforms. A new "G" suffix
183 for numbers indicates multiplication by 1024^3.
184
185 11. The GnuTLS support has been revamped; the three options gnutls_require_kx,
186 gnutls_require_mac & gnutls_require_protocols are no longer supported.
187 tls_require_ciphers is now parsed by gnutls_priority_init(3) as a priority
188 string, documentation for which is at:
189 http://www.gnu.org/software/gnutls/manual/html_node/Priority-Strings.html
190
191 SNI support has been added to Exim's GnuTLS integration too.
192
193 For sufficiently recent GnuTLS libraries, ${randint:..} will now use
194 gnutls_rnd(), asking for GNUTLS_RND_NONCE level randomness.
195
196 12. With OpenSSL, if built with EXPERIMENTAL_OCSP, a new option tls_ocsp_file
197 is now available. If the contents of the file are valid, then Exim will
198 send that back in response to a TLS status request; this is OCSP Stapling.
199 Exim will not maintain the contents of the file in any way: administrators
200 are responsible for ensuring that it is up-to-date.
201
202 See "experimental-spec.txt" for more details.
203
204 13. ${lookup dnsdb{ }} supports now SPF record types. They are handled
205 identically to TXT record lookups.
206
207 14. New expansion variable $tod_epoch_l for higher-precision time.
208
209 15. New global option tls_dh_max_bits, defaulting to current value of NSS
210 hard-coded limit of DH ephemeral bits, to fix interop problems caused by
211 GnuTLS 2.12 library recommending a bit count higher than NSS supports.
212
213 16. tls_dhparam now used by both OpenSSL and GnuTLS, can be path or identifier.
214 Option can now be a path or an identifier for a standard prime.
215 If unset, we use the DH prime from section 2.2 of RFC 5114, "ike23".
216 Set to "historic" to get the old GnuTLS behaviour of auto-generated DH
217 primes.
218
219 17. SSLv2 now disabled by default in OpenSSL. (Never supported by GnuTLS).
220 Use "openssl_options -no_sslv2" to re-enable support, if your OpenSSL
221 install was not built with OPENSSL_NO_SSL2 ("no-ssl2").
222
223
224 Version 4.77
225 ------------
226
227 1. New options for the ratelimit ACL condition: /count= and /unique=.
228 The /noupdate option has been replaced by a /readonly option.
229
230 2. The SMTP transport's protocol option may now be set to "smtps", to
231 use SSL-on-connect outbound.
232
233 3. New variable $av_failed, set true if the AV scanner deferred; ie, when
234 there is a problem talking to the AV scanner, or the AV scanner running.
235
236 4. New expansion conditions, "inlist" and "inlisti", which take simple lists
237 and check if the search item is a member of the list. This does not
238 support named lists, but does subject the list part to string expansion.
239
240 5. Unless the new EXPAND_LISTMATCH_RHS build option is set when Exim was
241 built, Exim no longer performs string expansion on the second string of
242 the match_* expansion conditions: "match_address", "match_domain",
243 "match_ip" & "match_local_part". Named lists can still be used.
244
245
246 Version 4.76
247 ------------
248
249 1. The global option "dns_use_edns0" may be set to coerce EDNS0 usage on
250 or off in the resolver library.
251
252
253 Version 4.75
254 ------------
255
256 1. In addition to the existing LDAP and LDAP/SSL ("ldaps") support, there
257 is now LDAP/TLS support, given sufficiently modern OpenLDAP client
258 libraries. The following global options have been added in support of
259 this: ldap_ca_cert_dir, ldap_ca_cert_file, ldap_cert_file, ldap_cert_key,
260 ldap_cipher_suite, ldap_require_cert, ldap_start_tls.
261
262 2. The pipe transport now takes a boolean option, "freeze_signal", default
263 false. When true, if the external delivery command exits on a signal then
264 Exim will freeze the message in the queue, instead of generating a bounce.
265
266 3. Log filenames may now use %M as an escape, instead of %D (still available).
267 The %M pattern expands to yyyymm, providing month-level resolution.
268
269 4. The $message_linecount variable is now updated for the maildir_tag option,
270 in the same way as $message_size, to reflect the real number of lines,
271 including any header additions or removals from transport.
272
273 5. When contacting a pool of SpamAssassin servers configured in spamd_address,
274 Exim now selects entries randomly, to better scale in a cluster setup.
275
276
277 Version 4.74
278 ------------
279
280 1. SECURITY FIX: privilege escalation flaw fixed. On Linux (and only Linux)
281 the flaw permitted the Exim run-time user to cause root to append to
282 arbitrary files of the attacker's choosing, with the content based
283 on content supplied by the attacker.
284
285 2. Exim now supports loading some lookup types at run-time, using your
286 platform's dlopen() functionality. This has limited platform support
287 and the intention is not to support every variant, it's limited to
288 dlopen(). This permits the main Exim binary to not be linked against
289 all the libraries needed for all the lookup types.
290
291
292 Version 4.73
293 ------------
294
295 NOTE: this version is not guaranteed backwards-compatible, please read the
296 items below carefully
297
298 1. A new main configuration option, "openssl_options", is available if Exim
299 is built with SSL support provided by OpenSSL. The option allows
300 administrators to specify OpenSSL options to be used on connections;
301 typically this is to set bug compatibility features which the OpenSSL
302 developers have not enabled by default. There may be security
303 consequences for certain options, so these should not be changed
304 frivolously.
305
306 2. A new pipe transport option, "permit_coredumps", may help with problem
307 diagnosis in some scenarios. Note that Exim is typically installed as
308 a setuid binary, which on most OSes will inhibit coredumps by default,
309 so that safety mechanism would have to be overridden for this option to
310 be able to take effect.
311
312 3. ClamAV 0.95 is now required for ClamAV support in Exim, unless
313 Local/Makefile sets: WITH_OLD_CLAMAV_STREAM=yes
314 Note that this switches Exim to use a new API ("INSTREAM") and a future
315 release of ClamAV will remove support for the old API ("STREAM").
316
317 The av_scanner option, when set to "clamd", now takes an optional third
318 part, "local", which causes Exim to pass a filename to ClamAV instead of
319 the file content. This is the same behaviour as when clamd is pointed at
320 a Unix-domain socket. For example:
321
322 av_scanner = clamd:192.0.2.3 1234:local
323
324 ClamAV's ExtendedDetectionInfo response format is now handled.
325
326 4. There is now a -bmalware option, restricted to admin users. This option
327 takes one parameter, a filename, and scans that file with Exim's
328 malware-scanning framework. This is intended purely as a debugging aid
329 to ensure that Exim's scanning is working, not to replace other tools.
330 Note that the ACL framework is not invoked, so if av_scanner references
331 ACL variables without a fallback then this will fail.
332
333 5. There is a new expansion operator, "reverse_ip", which will reverse IP
334 addresses; IPv4 into dotted quad, IPv6 into dotted nibble. Examples:
335
336 ${reverse_ip:192.0.2.4}
337 -> 4.2.0.192
338 ${reverse_ip:2001:0db8:c42:9:1:abcd:192.0.2.3}
339 -> 3.0.2.0.0.0.0.c.d.c.b.a.1.0.0.0.9.0.0.0.2.4.c.0.8.b.d.0.1.0.0.2
340
341 6. There is a new ACL control called "debug", to enable debug logging.
342 This allows selective logging of certain incoming transactions within
343 production environments, with some care. It takes two options, "tag"
344 and "opts"; "tag" is included in the filename of the log and "opts"
345 is used as per the -d<options> command-line option. Examples, which
346 don't all make sense in all contexts:
347
348 control = debug
349 control = debug/tag=.$sender_host_address
350 control = debug/opts=+expand+acl
351 control = debug/tag=.$message_exim_id/opts=+expand
352
353 7. It has always been implicit in the design and the documentation that
354 "the Exim user" is not root. src/EDITME said that using root was
355 "very strongly discouraged". This is not enough to keep people from
356 shooting themselves in the foot in days when many don't configure Exim
357 themselves but via package build managers. The security consequences of
358 running various bits of network code are severe if there should be bugs in
359 them. As such, the Exim user may no longer be root. If configured
360 statically, Exim will refuse to build. If configured as ref:user then Exim
361 will exit shortly after start-up. If you must shoot yourself in the foot,
362 then henceforth you will have to maintain your own local patches to strip
363 the safeties off.
364
365 8. There is a new expansion condition, bool_lax{}. Where bool{} uses the ACL
366 condition logic to determine truth/failure and will fail to expand many
367 strings, bool_lax{} uses the router condition logic, where most strings
368 do evaluate true.
369 Note: bool{00} is false, bool_lax{00} is true.
370
371 9. Routers now support multiple "condition" tests.
372
373 10. There is now a runtime configuration option "tcp_wrappers_daemon_name".
374 Setting this allows an admin to define which entry in the tcpwrappers
375 config file will be used to control access to the daemon. This option
376 is only available when Exim is built with USE_TCP_WRAPPERS. The
377 default value is set at build time using the TCP_WRAPPERS_DAEMON_NAME
378 build option.
379
380 11. [POSSIBLE CONFIG BREAKAGE] The default value for system_filter_user is now
381 the Exim run-time user, instead of root.
382
383 12. [POSSIBLE CONFIG BREAKAGE] ALT_CONFIG_ROOT_ONLY is no longer optional and
384 is forced on. This is mitigated by the new build option
385 TRUSTED_CONFIG_LIST which defines a list of configuration files which
386 are trusted; one per line. If a config file is owned by root and matches
387 a pathname in the list, then it may be invoked by the Exim build-time
388 user without Exim relinquishing root privileges.
389
390 13. [POSSIBLE CONFIG BREAKAGE] The Exim user is no longer automatically
391 trusted to supply -D<Macro[=Value]> overrides on the command-line. Going
392 forward, we recommend using TRUSTED_CONFIG_LIST with shim configs that
393 include the main config. As a transition mechanism, we are temporarily
394 providing a work-around: the new build option WHITELIST_D_MACROS provides
395 a colon-separated list of macro names which may be overridden by the Exim
396 run-time user. The values of these macros are constrained to the regex
397 ^[A-Za-z0-9_/.-]*$ (which explicitly does allow for empty values).
398
399
400 Version 4.72
401 ------------
402
403 1. TWO SECURITY FIXES: one relating to mail-spools which are globally
404 writable, the other to locking of MBX folders (not mbox).
405
406 2. MySQL stored procedures are now supported.
407
408 3. The dkim_domain transport option is now a list, not a single string, and
409 messages will be signed for each element in the list (discarding
410 duplicates).
411
412 4. The 4.70 release unexpectedly changed the behaviour of dnsdb TXT lookups
413 in the presence of multiple character strings within the RR. Prior to 4.70,
414 only the first string would be returned. The dnsdb lookup now, by default,
415 preserves the pre-4.70 semantics, but also now takes an extended output
416 separator specification. The separator can be followed by a semicolon, to
417 concatenate the individual text strings together with no join character,
418 or by a comma and a second separator character, in which case the text
419 strings within a TXT record are joined on that second character.
420 Administrators are reminded that DNS provides no ordering guarantees
421 between multiple records in an RRset. For example:
422
423 foo.example. IN TXT "a" "b" "c"
424 foo.example. IN TXT "d" "e" "f"
425
426 ${lookup dnsdb{>/ txt=foo.example}} -> "a/d"
427 ${lookup dnsdb{>/; txt=foo.example}} -> "def/abc"
428 ${lookup dnsdb{>/,+ txt=foo.example}} -> "a+b+c/d+e+f"
429
430
431 Version 4.70 / 4.71
432 -------------------
433
434 1. Native DKIM support without an external library.
435 (Note that if no action to prevent it is taken, a straight upgrade will
436 result in DKIM verification of all signed incoming emails. See spec
437 for details on conditionally disabling)
438
439 2. Experimental DCC support via dccifd (contributed by Wolfgang Breyha).
440
441 3. There is now a bool{} expansion condition which maps certain strings to
442 true/false condition values (most likely of use in conjunction with the
443 and{} expansion operator).
444
445 4. The $spam_score, $spam_bar and $spam_report variables are now available
446 at delivery time.
447
448 5. exim -bP now supports "macros", "macro_list" or "macro MACRO_NAME" as
449 options, provided that Exim is invoked by an admin_user.
450
451 6. There is a new option gnutls_compat_mode, when linked against GnuTLS,
452 which increases compatibility with older clients at the cost of decreased
453 security. Don't set this unless you need to support such clients.
454
455 7. There is a new expansion operator, ${randint:...} which will produce a
456 "random" number less than the supplied integer. This randomness is
457 not guaranteed to be cryptographically strong, but depending upon how
458 Exim was built may be better than the most naive schemes.
459
460 8. Exim now explicitly ensures that SHA256 is available when linked against
461 OpenSSL.
462
463 9. The transport_filter_timeout option now applies to SMTP transports too.
464
465
466 Version 4.69
467 ------------
468
469 1. Preliminary DKIM support in Experimental.
470
471
472 Version 4.68
473 ------------
474
475 1. The body_linecount and body_zerocount C variables are now exported in the
476 local_scan API.
477
478 2. When a dnslists lookup succeeds, the key that was looked up is now placed
479 in $dnslist_matched. When the key is an IP address, it is not reversed in
480 this variable (though it is, of course, in the actual lookup). In simple
481 cases, for example:
482
483 deny dnslists = spamhaus.example
484
485 the key is also available in another variable (in this case,
486 $sender_host_address). In more complicated cases, however, this is not
487 true. For example, using a data lookup might generate a dnslists lookup
488 like this:
489
490 deny dnslists = spamhaus.example/<|192.168.1.2|192.168.6.7|...
491
492 If this condition succeeds, the value in $dnslist_matched might be
493 192.168.6.7 (for example).
494
495 3. Authenticators now have a client_condition option. When Exim is running as
496 a client, it skips an authenticator whose client_condition expansion yields
497 "0", "no", or "false". This can be used, for example, to skip plain text
498 authenticators when the connection is not encrypted by a setting such as:
499
500 client_condition = ${if !eq{$tls_cipher}{}}
501
502 Note that the 4.67 documentation states that $tls_cipher contains the
503 cipher used for incoming messages. In fact, during SMTP delivery, it
504 contains the cipher used for the delivery. The same is true for
505 $tls_peerdn.
506
507 4. There is now a -Mvc <message-id> option, which outputs a copy of the
508 message to the standard output, in RFC 2822 format. The option can be used
509 only by an admin user.
510
511 5. There is now a /noupdate option for the ratelimit ACL condition. It
512 computes the rate and checks the limit as normal, but it does not update
513 the saved data. This means that, in relevant ACLs, it is possible to lookup
514 the existence of a specified (or auto-generated) ratelimit key without
515 incrementing the ratelimit counter for that key.
516
517 In order for this to be useful, another ACL entry must set the rate
518 for the same key somewhere (otherwise it will always be zero).
519
520 Example:
521
522 acl_check_connect:
523 # Read the rate; if it doesn't exist or is below the maximum
524 # we update it below
525 deny ratelimit = 100 / 5m / strict / noupdate
526 log_message = RATE: $sender_rate / $sender_rate_period \
527 (max $sender_rate_limit)
528
529 [... some other logic and tests...]
530
531 warn ratelimit = 100 / 5m / strict / per_cmd
532 log_message = RATE UPDATE: $sender_rate / $sender_rate_period \
533 (max $sender_rate_limit)
534 condition = ${if le{$sender_rate}{$sender_rate_limit}}
535
536 accept
537
538 6. The variable $max_received_linelength contains the number of bytes in the
539 longest line that was received as part of the message, not counting the
540 line termination character(s).
541
542 7. Host lists can now include +ignore_defer and +include_defer, analagous to
543 +ignore_unknown and +include_unknown. These options should be used with
544 care, probably only in non-critical host lists such as whitelists.
545
546 8. There's a new option called queue_only_load_latch, which defaults true.
547 If set false when queue_only_load is greater than zero, Exim re-evaluates
548 the load for each incoming message in an SMTP session. Otherwise, once one
549 message is queued, the remainder are also.
550
551 9. There is a new ACL, specified by acl_smtp_notquit, which is run in most
552 cases when an SMTP session ends without sending QUIT. However, when Exim
553 itself is is bad trouble, such as being unable to write to its log files,
554 this ACL is not run, because it might try to do things (such as write to
555 log files) that make the situation even worse.
556
557 Like the QUIT ACL, this new ACL is provided to make it possible to gather
558 statistics. Whatever it returns (accept or deny) is immaterial. The "delay"
559 modifier is forbidden in this ACL.
560
561 When the NOTQUIT ACL is running, the variable $smtp_notquit_reason is set
562 to a string that indicates the reason for the termination of the SMTP
563 connection. The possible values are:
564
565 acl-drop Another ACL issued a "drop" command
566 bad-commands Too many unknown or non-mail commands
567 command-timeout Timeout while reading SMTP commands
568 connection-lost The SMTP connection has been lost
569 data-timeout Timeout while reading message data
570 local-scan-error The local_scan() function crashed
571 local-scan-timeout The local_scan() function timed out
572 signal-exit SIGTERM or SIGINT
573 synchronization-error SMTP synchronization error
574 tls-failed TLS failed to start
575
576 In most cases when an SMTP connection is closed without having received
577 QUIT, Exim sends an SMTP response message before actually closing the
578 connection. With the exception of acl-drop, the default message can be
579 overridden by the "message" modifier in the NOTQUIT ACL. In the case of a
580 "drop" verb in another ACL, it is the message from the other ACL that is
581 used.
582
583 10. For MySQL and PostgreSQL lookups, it is now possible to specify a list of
584 servers with individual queries. This is done by starting the query with
585 "servers=x:y:z;", where each item in the list may take one of two forms:
586
587 (1) If it is just a host name, the appropriate global option (mysql_servers
588 or pgsql_servers) is searched for a host of the same name, and the
589 remaining parameters (database, user, password) are taken from there.
590
591 (2) If it contains any slashes, it is taken as a complete parameter set.
592
593 The list of servers is used in exactly the same was as the global list.
594 Once a connection to a server has happened and a query has been
595 successfully executed, processing of the lookup ceases.
596
597 This feature is intended for use in master/slave situations where updates
598 are occurring, and one wants to update a master rather than a slave. If the
599 masters are in the list for reading, you might have:
600
601 mysql_servers = slave1/db/name/pw:slave2/db/name/pw:master/db/name/pw
602
603 In an updating lookup, you could then write
604
605 ${lookup mysql{servers=master; UPDATE ...}
606
607 If, on the other hand, the master is not to be used for reading lookups:
608
609 pgsql_servers = slave1/db/name/pw:slave2/db/name/pw
610
611 you can still update the master by
612
613 ${lookup pgsql{servers=master/db/name/pw; UPDATE ...}
614
615 11. The message_body_newlines option (default FALSE, for backwards
616 compatibility) can be used to control whether newlines are present in
617 $message_body and $message_body_end. If it is FALSE, they are replaced by
618 spaces.
619
620
621 Version 4.67
622 ------------
623
624 1. There is a new log selector called smtp_no_mail, which is not included in
625 the default setting. When it is set, a line is written to the main log
626 whenever an accepted SMTP connection terminates without having issued a
627 MAIL command.
628
629 2. When an item in a dnslists list is followed by = and & and a list of IP
630 addresses, the behaviour was not clear when the lookup returned more than
631 one IP address. This has been solved by the addition of == and =& for "all"
632 rather than the default "any" matching.
633
634 3. Up till now, the only control over which cipher suites GnuTLS uses has been
635 for the cipher algorithms. New options have been added to allow some of the
636 other parameters to be varied.
637
638 4. There is a new compile-time option called ENABLE_DISABLE_FSYNC. When it is
639 set, Exim compiles a runtime option called disable_fsync.
640
641 5. There is a new variable called $smtp_count_at_connection_start.
642
643 6. There's a new control called no_pipelining.
644
645 7. There are two new variables called $sending_ip_address and $sending_port.
646 These are set whenever an SMTP connection to another host has been set up.
647
648 8. The expansion of the helo_data option in the smtp transport now happens
649 after the connection to the server has been made.
650
651 9. There is a new expansion operator ${rfc2047d: that decodes strings that
652 are encoded as per RFC 2047.
653
654 10. There is a new log selector called "pid", which causes the current process
655 id to be added to every log line, in square brackets, immediately after the
656 time and date.
657
658 11. Exim has been modified so that it flushes SMTP output before implementing
659 a delay in an ACL. It also flushes the output before performing a callout,
660 as this can take a substantial time. These behaviours can be disabled by
661 obeying control = no_delay_flush or control = no_callout_flush,
662 respectively, at some earlier stage of the connection.
663
664 12. There are two new expansion conditions that iterate over a list. They are
665 called forany and forall.
666
667 13. There's a new global option called dsn_from that can be used to vary the
668 contents of From: lines in bounces and other automatically generated
669 messages ("delivery status notifications" - hence the name of the option).
670
671 14. The smtp transport has a new option called hosts_avoid_pipelining.
672
673 15. By default, exigrep does case-insensitive matches. There is now a -I option
674 that makes it case-sensitive.
675
676 16. A number of new features ("addresses", "map", "filter", and "reduce") have
677 been added to string expansions to make it easier to process lists of
678 items, typically addresses.
679
680 17. There's a new ACL modifier called "continue". It does nothing of itself,
681 and processing of the ACL always continues with the next condition or
682 modifier. It is provided so that the side effects of expanding its argument
683 can be used.
684
685 18. It is now possible to use newline and other control characters (those with
686 values less than 32, plus DEL) as separators in lists.
687
688 19. The exigrep utility now has a -v option, which inverts the matching
689 condition.
690
691 20. The host_find_failed option in the manualroute router can now be set to
692 "ignore".
693
694
695 Version 4.66
696 ------------
697
698 No new features were added to 4.66.
699
700
701 Version 4.65
702 ------------
703
704 No new features were added to 4.65.
705
706
707 Version 4.64
708 ------------
709
710 1. ACL variables can now be given arbitrary names, as long as they start with
711 "acl_c" or "acl_m" (for connection variables and message variables), are at
712 least six characters long, with the sixth character being either a digit or
713 an underscore.
714
715 2. There is a new ACL modifier called log_reject_target. It makes it possible
716 to specify which logs are used for messages about ACL rejections.
717
718 3. There is a new authenticator called "dovecot". This is an interface to the
719 authentication facility of the Dovecot POP/IMAP server, which can support a
720 number of authentication methods.
721
722 4. The variable $message_headers_raw provides a concatenation of all the
723 messages's headers without any decoding. This is in contrast to
724 $message_headers, which does RFC2047 decoding on the header contents.
725
726 5. In a DNS black list, if two domain names, comma-separated, are given, the
727 second is used first to do an initial check, making use of any IP value
728 restrictions that are set. If there is a match, the first domain is used,
729 without any IP value restrictions, to get the TXT record.
730
731 6. All authenticators now have a server_condition option.
732
733 7. There is a new command-line option called -Mset. It is useful only in
734 conjunction with -be (that is, when testing string expansions). It must be
735 followed by a message id; Exim loads the given message from its spool
736 before doing the expansions.
737
738 8. Another similar new command-line option is called -bem. It operates like
739 -be except that it must be followed by the name of a file that contains a
740 message.
741
742 9. When an address is delayed because of a 4xx response to a RCPT command, it
743 is now the combination of sender and recipient that is delayed in
744 subsequent queue runs until its retry time is reached.
745
746 10. Unary negation and the bitwise logical operators and, or, xor, not, and
747 shift, have been added to the eval: and eval10: expansion items.
748
749 11. The variables $interface_address and $interface_port have been renamed
750 as $received_ip_address and $received_port, to make it clear that they
751 relate to message reception rather than delivery. (The old names remain
752 available for compatibility.)
753
754 12. The "message" modifier can now be used on "accept" and "discard" acl verbs
755 to vary the message that is sent when an SMTP command is accepted.
756
757
758 Version 4.63
759 ------------
760
761 1. There is a new Boolean option called filter_prepend_home for the redirect
762 router.
763
764 2. There is a new acl, set by acl_not_smtp_start, which is run right at the
765 start of receiving a non-SMTP message, before any of the message has been
766 read.
767
768 3. When an SMTP error message is specified in a "message" modifier in an ACL,
769 or in a :fail: or :defer: message in a redirect router, Exim now checks the
770 start of the message for an SMTP error code.
771
772 4. There is a new parameter for LDAP lookups called "referrals", which takes
773 one of the settings "follow" (the default) or "nofollow".
774
775 5. Version 20070721.2 of exipick now included, offering these new options:
776 --reverse
777 After all other sorting options have bee processed, reverse order
778 before displaying messages (-R is synonym).
779 --random
780 Randomize order of matching messages before displaying.
781 --size
782 Instead of displaying the matching messages, display the sum
783 of their sizes.
784 --sort <variable>[,<variable>...]
785 Before displaying matching messages, sort the messages according to
786 each messages value for each variable.
787 --not
788 Negate the value for every test (returns inverse output from the
789 same criteria without --not).
790
791
792 Version 4.62
793 ------------
794
795 1. The ${readsocket expansion item now supports Internet domain sockets as well
796 as Unix domain sockets. If the first argument begins "inet:", it must be of
797 the form "inet:host:port". The port is mandatory; it may be a number or the
798 name of a TCP port in /etc/services. The host may be a name, or it may be an
799 IP address. An ip address may optionally be enclosed in square brackets.
800 This is best for IPv6 addresses. For example:
801
802 ${readsocket{inet:[::1]:1234}{<request data>}...
803
804 Only a single host name may be given, but if looking it up yield more than
805 one IP address, they are each tried in turn until a connection is made. Once
806 a connection has been made, the behaviour is as for ${readsocket with a Unix
807 domain socket.
808
809 2. If a redirect router sets up file or pipe deliveries for more than one
810 incoming address, and the relevant transport has batch_max set greater than
811 one, a batch delivery now occurs.
812
813 3. The appendfile transport has a new option called maildirfolder_create_regex.
814 Its value is a regular expression. For a maildir delivery, this is matched
815 against the maildir directory; if it matches, Exim ensures that a
816 maildirfolder file is created alongside the new, cur, and tmp directories.
817
818
819 Version 4.61
820 ------------
821
822 The documentation is up-to-date for the 4.61 release. Major new features since
823 the 4.60 release are:
824
825 . An option called disable_ipv6, to disable the use of IPv6 completely.
826
827 . An increase in the number of ACL variables to 20 of each type.
828
829 . A change to use $auth1, $auth2, and $auth3 in authenticators instead of $1,
830 $2, $3, (though those are still set) because the numeric variables get used
831 for other things in complicated expansions.
832
833 . The default for rfc1413_query_timeout has been changed from 30s to 5s.
834
835 . It is possible to use setclassresources() on some BSD OS to control the
836 resources used in pipe deliveries.
837
838 . A new ACL modifier called add_header, which can be used with any verb.
839
840 . More errors are detectable in retry rules.
841
842 There are a number of other additions too.
843
844
845 Version 4.60
846 ------------
847
848 The documentation is up-to-date for the 4.60 release. Major new features since
849 the 4.50 release are:
850
851 . Support for SQLite.
852
853 . Support for IGNOREQUOTA in LMTP.
854
855 . Extensions to the "submission mode" features.
856
857 . Support for Client SMTP Authorization (CSA).
858
859 . Support for ratelimiting hosts and users.
860
861 . New expansion items to help with the BATV "prvs" scheme.
862
863 . A "match_ip" condition, that matches an IP address against a list.
864
865 There are many more minor changes.
866
867 ****