${utf8clean:string} expansion operator. Bug 1401
[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 4.83
10 ------------
11
12 1. If built with the EXPERIMENTAL_PROXY feature enabled, Exim can be
13 configured to expect an initial header from a proxy that will make the
14 actual external source IP:host be used in exim instead of the IP of the
15 proxy that is connecting to it.
16
17 2. New verify option header_names_ascii, which will check to make sure
18 there are no non-ASCII characters in header names. Exim itself handles
19 those non-ASCII characters, but downstream apps may not, so Exim can
20 detect and reject if those characters are present.
21
22 3. New expansion operator ${utf8clean:string} to replace malformed UTF8
23 codepoints with valid ones.
24
25
26 Version 4.82
27 ------------
28
29 1. New command-line option -bI:sieve will list all supported sieve extensions
30 of this Exim build on standard output, one per line.
31 ManageSieve (RFC 5804) providers managing scripts for use by Exim should
32 query this to establish the correct list to include in the protocol's
33 SIEVE capability line.
34
35 2. If the -n option is combined with the -bP option, then the name of an
36 emitted option is not output, only the value (if visible to you).
37 For instance, "exim -n -bP pid_file_path" should just emit a pathname
38 followed by a newline, and no other text.
39
40 3. When built with SUPPORT_TLS and USE_GNUTLS, the SMTP transport driver now
41 has a "tls_dh_min_bits" option, to set the minimum acceptable number of
42 bits in the Diffie-Hellman prime offered by a server (in DH ciphersuites)
43 acceptable for security. (Option accepted but ignored if using OpenSSL).
44 Defaults to 1024, the old value. May be lowered only to 512, or raised as
45 far as you like. Raising this may hinder TLS interoperability with other
46 sites and is not currently recommended. Lowering this will permit you to
47 establish a TLS session which is not as secure as you might like.
48
49 Unless you really know what you are doing, leave it alone.
50
51 4. If not built with DISABLE_DNSSEC, Exim now has the main option
52 dns_dnssec_ok; if set to 1 then Exim will initialise the resolver library
53 to send the DO flag to your recursive resolver. If you have a recursive
54 resolver, which can set the Authenticated Data (AD) flag in results, Exim
55 can now detect this. Exim does not perform validation itself, instead
56 relying upon a trusted path to the resolver.
57
58 Current status: work-in-progress; $sender_host_dnssec variable added.
59
60 5. DSCP support for outbound connections: on a transport using the smtp driver,
61 set "dscp = ef", for instance, to cause the connections to have the relevant
62 DSCP (IPv4 TOS or IPv6 TCLASS) value in the header.
63
64 Similarly for inbound connections, there is a new control modifier, dscp,
65 so "warn control = dscp/ef" in the connect ACL, or after authentication.
66
67 Supported values depend upon system libraries. "exim -bI:dscp" to list the
68 ones Exim knows of. You can also set a raw number 0..0x3F.
69
70 6. The -G command-line flag is no longer ignored; it is now equivalent to an
71 ACL setting "control = suppress_local_fixups". The -L command-line flag
72 is now accepted and forces use of syslog, with the provided tag as the
73 process name. A few other flags used by Sendmail are now accepted and
74 ignored.
75
76 7. New cutthrough routing feature. Requested by a "control = cutthrough_delivery"
77 ACL modifier; works for single-recipient mails which are recieved on and
78 deliverable via SMTP. Using the connection made for a recipient verify,
79 if requested before the verify, or a new one made for the purpose while
80 the inbound connection is still active. The bulk of the mail item is copied
81 direct from the inbound socket to the outbound (as well as the spool file).
82 When the source notifies the end of data, the data acceptance by the destination
83 is negociated before the acceptance is sent to the source. If the destination
84 does not accept the mail item, for example due to content-scanning, the item
85 is not accepted from the source and therefore there is no need to generate
86 a bounce mail. This is of benefit when providing a secondary-MX service.
87 The downside is that delays are under the control of the ultimate destination
88 system not your own.
89
90 The Recieved-by: header on items delivered by cutthrough is generated
91 early in reception rather than at the end; this will affect any timestamp
92 included. The log line showing delivery is recorded before that showing
93 reception; it uses a new ">>" tag instead of "=>".
94
95 To support the feature, verify-callout connections can now use ESMTP and TLS.
96 The usual smtp transport options are honoured, plus a (new, default everything)
97 hosts_verify_avoid_tls.
98
99 New variable families named tls_in_cipher, tls_out_cipher etc. are introduced
100 for specific access to the information for each connection. The old names
101 are present for now but deprecated.
102
103 Not yet supported: IGNOREQUOTA, SIZE, PIPELINING.
104
105 8. New expansion operators ${listnamed:name} to get the content of a named list
106 and ${listcount:string} to count the items in a list.
107
108 9. New global option "gnutls_allow_auto_pkcs11", defaults false. The GnuTLS
109 rewrite in 4.80 combines with GnuTLS 2.12.0 or later, to autoload PKCS11
110 modules. For some situations this is desirable, but we expect admin in
111 those situations to know they want the feature. More commonly, it means
112 that GUI user modules get loaded and are broken by the setuid Exim being
113 unable to access files specified in environment variables and passed
114 through, thus breakage. So we explicitly inhibit the PKCS11 initialisation
115 unless this new option is set.
116
117 Some older OS's with earlier versions of GnuTLS might not have pkcs11 ability,
118 so have also added a build option which can be used to build Exim with GnuTLS
119 but without trying to use any kind of PKCS11 support. Uncomment this in the
120 Local/Makefile:
121
122 AVOID_GNUTLS_PKCS11=yes
123
124 10. The "acl = name" condition on an ACL now supports optional arguments.
125 New expansion item "${acl {name}{arg}...}" and expansion condition
126 "acl {{name}{arg}...}" are added. In all cases up to nine arguments
127 can be used, appearing in $acl_arg1 to $acl_arg9 for the called ACL.
128 Variable $acl_narg contains the number of arguments. If the ACL sets
129 a "message =" value this becomes the result of the expansion item,
130 or the value of $value for the expansion condition. If the ACL returns
131 accept the expansion condition is true; if reject, false. A defer
132 return results in a forced fail.
133
134 11. Routers and transports can now have multiple headers_add and headers_remove
135 option lines. The concatenated list is used.
136
137 12. New ACL modifier "remove_header" can remove headers before message gets
138 handled by routers/transports.
139
140 13. New dnsdb lookup pseudo-type "a+". A sequence of "a6" (if configured),
141 "aaaa" and "a" lookups is done and the full set of results returned.
142
143 14. New expansion variable $headers_added with content from ACL add_header
144 modifier (but not yet added to messsage).
145
146 15. New 8bitmime status logging option for received messages. Log field "M8S".
147
148 16. New authenticated_sender logging option, adding to log field "A".
149
150 17. New expansion variables $router_name and $transport_name. Useful
151 particularly for debug_print as -bt commandline option does not
152 require privilege whereas -d does.
153
154 18. If built with EXPERIMENTAL_PRDR, per-recipient data responses per a
155 proposed extension to SMTP from Eric Hall.
156
157 19. The pipe transport has gained the force_command option, to allow
158 decorating commands from user .forward pipe aliases with prefix
159 wrappers, for instance.
160
161 20. Callout connections can now AUTH; the same controls as normal delivery
162 connections apply.
163
164 21. Support for DMARC, using opendmarc libs, can be enabled. It adds new
165 options: dmarc_forensic_sender, dmarc_history_file, and dmarc_tld_file.
166 It adds new expansion variables $dmarc_ar_header, $dmarc_status,
167 $dmarc_status_text, and $dmarc_used_domain. It adds a new acl modifier
168 dmarc_status. It adds new control flags dmarc_disable_verify and
169 dmarc_enable_forensic.
170
171 22. Add expansion variable $authenticated_fail_id, which is the username
172 provided to the authentication method which failed. It is available
173 for use in subsequent ACL processing (typically quit or notquit ACLs).
174
175 23. New ACL modifer "udpsend" can construct a UDP packet to send to a given
176 UDP host and port.
177
178 24. New ${hexquote:..string..} expansion operator converts non-printable
179 characters in the string to \xNN form.
180
181 25. Experimental TPDA (Transport Post Delivery Action) function added.
182 Patch provided by Axel Rau.
183
184 26. Experimental Redis lookup added. Patch provided by Warren Baker.
185
186
187 Version 4.80
188 ------------
189
190 1. New authenticator driver, "gsasl". Server-only (at present).
191 This is a SASL interface, licensed under GPL, which can be found at
192 http://www.gnu.org/software/gsasl/.
193 This system does not provide sources of data for authentication, so
194 careful use needs to be made of the conditions in Exim.
195
196 2. New authenticator driver, "heimdal_gssapi". Server-only.
197 A replacement for using cyrus_sasl with Heimdal, now that $KRB5_KTNAME
198 is no longer honoured for setuid programs by Heimdal. Use the
199 "server_keytab" option to point to the keytab.
200
201 3. The "pkg-config" system can now be used when building Exim to reference
202 cflags and library information for lookups and authenticators, rather
203 than having to update "CFLAGS", "AUTH_LIBS", "LOOKUP_INCLUDE" and
204 "LOOKUP_LIBS" directly. Similarly for handling the TLS library support
205 without adjusting "TLS_INCLUDE" and "TLS_LIBS".
206
207 In addition, setting PCRE_CONFIG=yes will query the pcre-config tool to
208 find the headers and libraries for PCRE.
209
210 4. New expansion variable $tls_bits.
211
212 5. New lookup type, "dbmjz". Key is an Exim list, the elements of which will
213 be joined together with ASCII NUL characters to construct the key to pass
214 into the DBM library. Can be used with gsasl to access sasldb2 files as
215 used by Cyrus SASL.
216
217 6. OpenSSL now supports TLS1.1 and TLS1.2 with OpenSSL 1.0.1.
218
219 Avoid release 1.0.1a if you can. Note that the default value of
220 "openssl_options" is no longer "+dont_insert_empty_fragments", as that
221 increased susceptibility to attack. This may still have interoperability
222 implications for very old clients (see version 4.31 change 37) but
223 administrators can choose to make the trade-off themselves and restore
224 compatibility at the cost of session security.
225
226 7. Use of the new expansion variable $tls_sni in the main configuration option
227 tls_certificate will cause Exim to re-expand the option, if the client
228 sends the TLS Server Name Indication extension, to permit choosing a
229 different certificate; tls_privatekey will also be re-expanded. You must
230 still set these options to expand to valid files when $tls_sni is not set.
231
232 The SMTP Transport has gained the option tls_sni, which will set a hostname
233 for outbound TLS sessions, and set $tls_sni too.
234
235 A new log_selector, +tls_sni, has been added, to log received SNI values
236 for Exim as a server.
237
238 8. The existing "accept_8bitmime" option now defaults to true. This means
239 that Exim is deliberately not strictly RFC compliant. We're following
240 Dan Bernstein's advice in http://cr.yp.to/smtp/8bitmime.html by default.
241 Those who disagree, or know that they are talking to mail servers that,
242 even today, are not 8-bit clean, need to turn off this option.
243
244 9. Exim can now be started with -bw (with an optional timeout, given as
245 -bw<timespec>). With this, stdin at startup is a socket that is
246 already listening for connections. This has a more modern name of
247 "socket activation", but forcing the activated socket to fd 0. We're
248 interested in adding more support for modern variants.
249
250 10. ${eval } now uses 64-bit values on supporting platforms. A new "G" suffix
251 for numbers indicates multiplication by 1024^3.
252
253 11. The GnuTLS support has been revamped; the three options gnutls_require_kx,
254 gnutls_require_mac & gnutls_require_protocols are no longer supported.
255 tls_require_ciphers is now parsed by gnutls_priority_init(3) as a priority
256 string, documentation for which is at:
257 http://www.gnutls.org/manual/html_node/Priority-Strings.html
258
259 SNI support has been added to Exim's GnuTLS integration too.
260
261 For sufficiently recent GnuTLS libraries, ${randint:..} will now use
262 gnutls_rnd(), asking for GNUTLS_RND_NONCE level randomness.
263
264 12. With OpenSSL, if built with EXPERIMENTAL_OCSP, a new option tls_ocsp_file
265 is now available. If the contents of the file are valid, then Exim will
266 send that back in response to a TLS status request; this is OCSP Stapling.
267 Exim will not maintain the contents of the file in any way: administrators
268 are responsible for ensuring that it is up-to-date.
269
270 See "experimental-spec.txt" for more details.
271
272 13. ${lookup dnsdb{ }} supports now SPF record types. They are handled
273 identically to TXT record lookups.
274
275 14. New expansion variable $tod_epoch_l for higher-precision time.
276
277 15. New global option tls_dh_max_bits, defaulting to current value of NSS
278 hard-coded limit of DH ephemeral bits, to fix interop problems caused by
279 GnuTLS 2.12 library recommending a bit count higher than NSS supports.
280
281 16. tls_dhparam now used by both OpenSSL and GnuTLS, can be path or identifier.
282 Option can now be a path or an identifier for a standard prime.
283 If unset, we use the DH prime from section 2.2 of RFC 5114, "ike23".
284 Set to "historic" to get the old GnuTLS behaviour of auto-generated DH
285 primes.
286
287 17. SSLv2 now disabled by default in OpenSSL. (Never supported by GnuTLS).
288 Use "openssl_options -no_sslv2" to re-enable support, if your OpenSSL
289 install was not built with OPENSSL_NO_SSL2 ("no-ssl2").
290
291
292 Version 4.77
293 ------------
294
295 1. New options for the ratelimit ACL condition: /count= and /unique=.
296 The /noupdate option has been replaced by a /readonly option.
297
298 2. The SMTP transport's protocol option may now be set to "smtps", to
299 use SSL-on-connect outbound.
300
301 3. New variable $av_failed, set true if the AV scanner deferred; ie, when
302 there is a problem talking to the AV scanner, or the AV scanner running.
303
304 4. New expansion conditions, "inlist" and "inlisti", which take simple lists
305 and check if the search item is a member of the list. This does not
306 support named lists, but does subject the list part to string expansion.
307
308 5. Unless the new EXPAND_LISTMATCH_RHS build option is set when Exim was
309 built, Exim no longer performs string expansion on the second string of
310 the match_* expansion conditions: "match_address", "match_domain",
311 "match_ip" & "match_local_part". Named lists can still be used.
312
313
314 Version 4.76
315 ------------
316
317 1. The global option "dns_use_edns0" may be set to coerce EDNS0 usage on
318 or off in the resolver library.
319
320
321 Version 4.75
322 ------------
323
324 1. In addition to the existing LDAP and LDAP/SSL ("ldaps") support, there
325 is now LDAP/TLS support, given sufficiently modern OpenLDAP client
326 libraries. The following global options have been added in support of
327 this: ldap_ca_cert_dir, ldap_ca_cert_file, ldap_cert_file, ldap_cert_key,
328 ldap_cipher_suite, ldap_require_cert, ldap_start_tls.
329
330 2. The pipe transport now takes a boolean option, "freeze_signal", default
331 false. When true, if the external delivery command exits on a signal then
332 Exim will freeze the message in the queue, instead of generating a bounce.
333
334 3. Log filenames may now use %M as an escape, instead of %D (still available).
335 The %M pattern expands to yyyymm, providing month-level resolution.
336
337 4. The $message_linecount variable is now updated for the maildir_tag option,
338 in the same way as $message_size, to reflect the real number of lines,
339 including any header additions or removals from transport.
340
341 5. When contacting a pool of SpamAssassin servers configured in spamd_address,
342 Exim now selects entries randomly, to better scale in a cluster setup.
343
344
345 Version 4.74
346 ------------
347
348 1. SECURITY FIX: privilege escalation flaw fixed. On Linux (and only Linux)
349 the flaw permitted the Exim run-time user to cause root to append to
350 arbitrary files of the attacker's choosing, with the content based
351 on content supplied by the attacker.
352
353 2. Exim now supports loading some lookup types at run-time, using your
354 platform's dlopen() functionality. This has limited platform support
355 and the intention is not to support every variant, it's limited to
356 dlopen(). This permits the main Exim binary to not be linked against
357 all the libraries needed for all the lookup types.
358
359
360 Version 4.73
361 ------------
362
363 NOTE: this version is not guaranteed backwards-compatible, please read the
364 items below carefully
365
366 1. A new main configuration option, "openssl_options", is available if Exim
367 is built with SSL support provided by OpenSSL. The option allows
368 administrators to specify OpenSSL options to be used on connections;
369 typically this is to set bug compatibility features which the OpenSSL
370 developers have not enabled by default. There may be security
371 consequences for certain options, so these should not be changed
372 frivolously.
373
374 2. A new pipe transport option, "permit_coredumps", may help with problem
375 diagnosis in some scenarios. Note that Exim is typically installed as
376 a setuid binary, which on most OSes will inhibit coredumps by default,
377 so that safety mechanism would have to be overridden for this option to
378 be able to take effect.
379
380 3. ClamAV 0.95 is now required for ClamAV support in Exim, unless
381 Local/Makefile sets: WITH_OLD_CLAMAV_STREAM=yes
382 Note that this switches Exim to use a new API ("INSTREAM") and a future
383 release of ClamAV will remove support for the old API ("STREAM").
384
385 The av_scanner option, when set to "clamd", now takes an optional third
386 part, "local", which causes Exim to pass a filename to ClamAV instead of
387 the file content. This is the same behaviour as when clamd is pointed at
388 a Unix-domain socket. For example:
389
390 av_scanner = clamd:192.0.2.3 1234:local
391
392 ClamAV's ExtendedDetectionInfo response format is now handled.
393
394 4. There is now a -bmalware option, restricted to admin users. This option
395 takes one parameter, a filename, and scans that file with Exim's
396 malware-scanning framework. This is intended purely as a debugging aid
397 to ensure that Exim's scanning is working, not to replace other tools.
398 Note that the ACL framework is not invoked, so if av_scanner references
399 ACL variables without a fallback then this will fail.
400
401 5. There is a new expansion operator, "reverse_ip", which will reverse IP
402 addresses; IPv4 into dotted quad, IPv6 into dotted nibble. Examples:
403
404 ${reverse_ip:192.0.2.4}
405 -> 4.2.0.192
406 ${reverse_ip:2001:0db8:c42:9:1:abcd:192.0.2.3}
407 -> 3.0.2.0.0.0.0.c.d.c.b.a.1.0.0.0.9.0.0.0.2.4.c.0.8.b.d.0.1.0.0.2
408
409 6. There is a new ACL control called "debug", to enable debug logging.
410 This allows selective logging of certain incoming transactions within
411 production environments, with some care. It takes two options, "tag"
412 and "opts"; "tag" is included in the filename of the log and "opts"
413 is used as per the -d<options> command-line option. Examples, which
414 don't all make sense in all contexts:
415
416 control = debug
417 control = debug/tag=.$sender_host_address
418 control = debug/opts=+expand+acl
419 control = debug/tag=.$message_exim_id/opts=+expand
420
421 7. It has always been implicit in the design and the documentation that
422 "the Exim user" is not root. src/EDITME said that using root was
423 "very strongly discouraged". This is not enough to keep people from
424 shooting themselves in the foot in days when many don't configure Exim
425 themselves but via package build managers. The security consequences of
426 running various bits of network code are severe if there should be bugs in
427 them. As such, the Exim user may no longer be root. If configured
428 statically, Exim will refuse to build. If configured as ref:user then Exim
429 will exit shortly after start-up. If you must shoot yourself in the foot,
430 then henceforth you will have to maintain your own local patches to strip
431 the safeties off.
432
433 8. There is a new expansion condition, bool_lax{}. Where bool{} uses the ACL
434 condition logic to determine truth/failure and will fail to expand many
435 strings, bool_lax{} uses the router condition logic, where most strings
436 do evaluate true.
437 Note: bool{00} is false, bool_lax{00} is true.
438
439 9. Routers now support multiple "condition" tests.
440
441 10. There is now a runtime configuration option "tcp_wrappers_daemon_name".
442 Setting this allows an admin to define which entry in the tcpwrappers
443 config file will be used to control access to the daemon. This option
444 is only available when Exim is built with USE_TCP_WRAPPERS. The
445 default value is set at build time using the TCP_WRAPPERS_DAEMON_NAME
446 build option.
447
448 11. [POSSIBLE CONFIG BREAKAGE] The default value for system_filter_user is now
449 the Exim run-time user, instead of root.
450
451 12. [POSSIBLE CONFIG BREAKAGE] ALT_CONFIG_ROOT_ONLY is no longer optional and
452 is forced on. This is mitigated by the new build option
453 TRUSTED_CONFIG_LIST which defines a list of configuration files which
454 are trusted; one per line. If a config file is owned by root and matches
455 a pathname in the list, then it may be invoked by the Exim build-time
456 user without Exim relinquishing root privileges.
457
458 13. [POSSIBLE CONFIG BREAKAGE] The Exim user is no longer automatically
459 trusted to supply -D<Macro[=Value]> overrides on the command-line. Going
460 forward, we recommend using TRUSTED_CONFIG_LIST with shim configs that
461 include the main config. As a transition mechanism, we are temporarily
462 providing a work-around: the new build option WHITELIST_D_MACROS provides
463 a colon-separated list of macro names which may be overridden by the Exim
464 run-time user. The values of these macros are constrained to the regex
465 ^[A-Za-z0-9_/.-]*$ (which explicitly does allow for empty values).
466
467
468 Version 4.72
469 ------------
470
471 1. TWO SECURITY FIXES: one relating to mail-spools which are globally
472 writable, the other to locking of MBX folders (not mbox).
473
474 2. MySQL stored procedures are now supported.
475
476 3. The dkim_domain transport option is now a list, not a single string, and
477 messages will be signed for each element in the list (discarding
478 duplicates).
479
480 4. The 4.70 release unexpectedly changed the behaviour of dnsdb TXT lookups
481 in the presence of multiple character strings within the RR. Prior to 4.70,
482 only the first string would be returned. The dnsdb lookup now, by default,
483 preserves the pre-4.70 semantics, but also now takes an extended output
484 separator specification. The separator can be followed by a semicolon, to
485 concatenate the individual text strings together with no join character,
486 or by a comma and a second separator character, in which case the text
487 strings within a TXT record are joined on that second character.
488 Administrators are reminded that DNS provides no ordering guarantees
489 between multiple records in an RRset. For example:
490
491 foo.example. IN TXT "a" "b" "c"
492 foo.example. IN TXT "d" "e" "f"
493
494 ${lookup dnsdb{>/ txt=foo.example}} -> "a/d"
495 ${lookup dnsdb{>/; txt=foo.example}} -> "def/abc"
496 ${lookup dnsdb{>/,+ txt=foo.example}} -> "a+b+c/d+e+f"
497
498
499 Version 4.70 / 4.71
500 -------------------
501
502 1. Native DKIM support without an external library.
503 (Note that if no action to prevent it is taken, a straight upgrade will
504 result in DKIM verification of all signed incoming emails. See spec
505 for details on conditionally disabling)
506
507 2. Experimental DCC support via dccifd (contributed by Wolfgang Breyha).
508
509 3. There is now a bool{} expansion condition which maps certain strings to
510 true/false condition values (most likely of use in conjunction with the
511 and{} expansion operator).
512
513 4. The $spam_score, $spam_bar and $spam_report variables are now available
514 at delivery time.
515
516 5. exim -bP now supports "macros", "macro_list" or "macro MACRO_NAME" as
517 options, provided that Exim is invoked by an admin_user.
518
519 6. There is a new option gnutls_compat_mode, when linked against GnuTLS,
520 which increases compatibility with older clients at the cost of decreased
521 security. Don't set this unless you need to support such clients.
522
523 7. There is a new expansion operator, ${randint:...} which will produce a
524 "random" number less than the supplied integer. This randomness is
525 not guaranteed to be cryptographically strong, but depending upon how
526 Exim was built may be better than the most naive schemes.
527
528 8. Exim now explicitly ensures that SHA256 is available when linked against
529 OpenSSL.
530
531 9. The transport_filter_timeout option now applies to SMTP transports too.
532
533
534 Version 4.69
535 ------------
536
537 1. Preliminary DKIM support in Experimental.
538
539
540 Version 4.68
541 ------------
542
543 1. The body_linecount and body_zerocount C variables are now exported in the
544 local_scan API.
545
546 2. When a dnslists lookup succeeds, the key that was looked up is now placed
547 in $dnslist_matched. When the key is an IP address, it is not reversed in
548 this variable (though it is, of course, in the actual lookup). In simple
549 cases, for example:
550
551 deny dnslists = spamhaus.example
552
553 the key is also available in another variable (in this case,
554 $sender_host_address). In more complicated cases, however, this is not
555 true. For example, using a data lookup might generate a dnslists lookup
556 like this:
557
558 deny dnslists = spamhaus.example/<|192.168.1.2|192.168.6.7|...
559
560 If this condition succeeds, the value in $dnslist_matched might be
561 192.168.6.7 (for example).
562
563 3. Authenticators now have a client_condition option. When Exim is running as
564 a client, it skips an authenticator whose client_condition expansion yields
565 "0", "no", or "false". This can be used, for example, to skip plain text
566 authenticators when the connection is not encrypted by a setting such as:
567
568 client_condition = ${if !eq{$tls_cipher}{}}
569
570 Note that the 4.67 documentation states that $tls_cipher contains the
571 cipher used for incoming messages. In fact, during SMTP delivery, it
572 contains the cipher used for the delivery. The same is true for
573 $tls_peerdn.
574
575 4. There is now a -Mvc <message-id> option, which outputs a copy of the
576 message to the standard output, in RFC 2822 format. The option can be used
577 only by an admin user.
578
579 5. There is now a /noupdate option for the ratelimit ACL condition. It
580 computes the rate and checks the limit as normal, but it does not update
581 the saved data. This means that, in relevant ACLs, it is possible to lookup
582 the existence of a specified (or auto-generated) ratelimit key without
583 incrementing the ratelimit counter for that key.
584
585 In order for this to be useful, another ACL entry must set the rate
586 for the same key somewhere (otherwise it will always be zero).
587
588 Example:
589
590 acl_check_connect:
591 # Read the rate; if it doesn't exist or is below the maximum
592 # we update it below
593 deny ratelimit = 100 / 5m / strict / noupdate
594 log_message = RATE: $sender_rate / $sender_rate_period \
595 (max $sender_rate_limit)
596
597 [... some other logic and tests...]
598
599 warn ratelimit = 100 / 5m / strict / per_cmd
600 log_message = RATE UPDATE: $sender_rate / $sender_rate_period \
601 (max $sender_rate_limit)
602 condition = ${if le{$sender_rate}{$sender_rate_limit}}
603
604 accept
605
606 6. The variable $max_received_linelength contains the number of bytes in the
607 longest line that was received as part of the message, not counting the
608 line termination character(s).
609
610 7. Host lists can now include +ignore_defer and +include_defer, analagous to
611 +ignore_unknown and +include_unknown. These options should be used with
612 care, probably only in non-critical host lists such as whitelists.
613
614 8. There's a new option called queue_only_load_latch, which defaults true.
615 If set false when queue_only_load is greater than zero, Exim re-evaluates
616 the load for each incoming message in an SMTP session. Otherwise, once one
617 message is queued, the remainder are also.
618
619 9. There is a new ACL, specified by acl_smtp_notquit, which is run in most
620 cases when an SMTP session ends without sending QUIT. However, when Exim
621 itself is is bad trouble, such as being unable to write to its log files,
622 this ACL is not run, because it might try to do things (such as write to
623 log files) that make the situation even worse.
624
625 Like the QUIT ACL, this new ACL is provided to make it possible to gather
626 statistics. Whatever it returns (accept or deny) is immaterial. The "delay"
627 modifier is forbidden in this ACL.
628
629 When the NOTQUIT ACL is running, the variable $smtp_notquit_reason is set
630 to a string that indicates the reason for the termination of the SMTP
631 connection. The possible values are:
632
633 acl-drop Another ACL issued a "drop" command
634 bad-commands Too many unknown or non-mail commands
635 command-timeout Timeout while reading SMTP commands
636 connection-lost The SMTP connection has been lost
637 data-timeout Timeout while reading message data
638 local-scan-error The local_scan() function crashed
639 local-scan-timeout The local_scan() function timed out
640 signal-exit SIGTERM or SIGINT
641 synchronization-error SMTP synchronization error
642 tls-failed TLS failed to start
643
644 In most cases when an SMTP connection is closed without having received
645 QUIT, Exim sends an SMTP response message before actually closing the
646 connection. With the exception of acl-drop, the default message can be
647 overridden by the "message" modifier in the NOTQUIT ACL. In the case of a
648 "drop" verb in another ACL, it is the message from the other ACL that is
649 used.
650
651 10. For MySQL and PostgreSQL lookups, it is now possible to specify a list of
652 servers with individual queries. This is done by starting the query with
653 "servers=x:y:z;", where each item in the list may take one of two forms:
654
655 (1) If it is just a host name, the appropriate global option (mysql_servers
656 or pgsql_servers) is searched for a host of the same name, and the
657 remaining parameters (database, user, password) are taken from there.
658
659 (2) If it contains any slashes, it is taken as a complete parameter set.
660
661 The list of servers is used in exactly the same was as the global list.
662 Once a connection to a server has happened and a query has been
663 successfully executed, processing of the lookup ceases.
664
665 This feature is intended for use in master/slave situations where updates
666 are occurring, and one wants to update a master rather than a slave. If the
667 masters are in the list for reading, you might have:
668
669 mysql_servers = slave1/db/name/pw:slave2/db/name/pw:master/db/name/pw
670
671 In an updating lookup, you could then write
672
673 ${lookup mysql{servers=master; UPDATE ...}
674
675 If, on the other hand, the master is not to be used for reading lookups:
676
677 pgsql_servers = slave1/db/name/pw:slave2/db/name/pw
678
679 you can still update the master by
680
681 ${lookup pgsql{servers=master/db/name/pw; UPDATE ...}
682
683 11. The message_body_newlines option (default FALSE, for backwards
684 compatibility) can be used to control whether newlines are present in
685 $message_body and $message_body_end. If it is FALSE, they are replaced by
686 spaces.
687
688
689 Version 4.67
690 ------------
691
692 1. There is a new log selector called smtp_no_mail, which is not included in
693 the default setting. When it is set, a line is written to the main log
694 whenever an accepted SMTP connection terminates without having issued a
695 MAIL command.
696
697 2. When an item in a dnslists list is followed by = and & and a list of IP
698 addresses, the behaviour was not clear when the lookup returned more than
699 one IP address. This has been solved by the addition of == and =& for "all"
700 rather than the default "any" matching.
701
702 3. Up till now, the only control over which cipher suites GnuTLS uses has been
703 for the cipher algorithms. New options have been added to allow some of the
704 other parameters to be varied.
705
706 4. There is a new compile-time option called ENABLE_DISABLE_FSYNC. When it is
707 set, Exim compiles a runtime option called disable_fsync.
708
709 5. There is a new variable called $smtp_count_at_connection_start.
710
711 6. There's a new control called no_pipelining.
712
713 7. There are two new variables called $sending_ip_address and $sending_port.
714 These are set whenever an SMTP connection to another host has been set up.
715
716 8. The expansion of the helo_data option in the smtp transport now happens
717 after the connection to the server has been made.
718
719 9. There is a new expansion operator ${rfc2047d: that decodes strings that
720 are encoded as per RFC 2047.
721
722 10. There is a new log selector called "pid", which causes the current process
723 id to be added to every log line, in square brackets, immediately after the
724 time and date.
725
726 11. Exim has been modified so that it flushes SMTP output before implementing
727 a delay in an ACL. It also flushes the output before performing a callout,
728 as this can take a substantial time. These behaviours can be disabled by
729 obeying control = no_delay_flush or control = no_callout_flush,
730 respectively, at some earlier stage of the connection.
731
732 12. There are two new expansion conditions that iterate over a list. They are
733 called forany and forall.
734
735 13. There's a new global option called dsn_from that can be used to vary the
736 contents of From: lines in bounces and other automatically generated
737 messages ("delivery status notifications" - hence the name of the option).
738
739 14. The smtp transport has a new option called hosts_avoid_pipelining.
740
741 15. By default, exigrep does case-insensitive matches. There is now a -I option
742 that makes it case-sensitive.
743
744 16. A number of new features ("addresses", "map", "filter", and "reduce") have
745 been added to string expansions to make it easier to process lists of
746 items, typically addresses.
747
748 17. There's a new ACL modifier called "continue". It does nothing of itself,
749 and processing of the ACL always continues with the next condition or
750 modifier. It is provided so that the side effects of expanding its argument
751 can be used.
752
753 18. It is now possible to use newline and other control characters (those with
754 values less than 32, plus DEL) as separators in lists.
755
756 19. The exigrep utility now has a -v option, which inverts the matching
757 condition.
758
759 20. The host_find_failed option in the manualroute router can now be set to
760 "ignore".
761
762
763 Version 4.66
764 ------------
765
766 No new features were added to 4.66.
767
768
769 Version 4.65
770 ------------
771
772 No new features were added to 4.65.
773
774
775 Version 4.64
776 ------------
777
778 1. ACL variables can now be given arbitrary names, as long as they start with
779 "acl_c" or "acl_m" (for connection variables and message variables), are at
780 least six characters long, with the sixth character being either a digit or
781 an underscore.
782
783 2. There is a new ACL modifier called log_reject_target. It makes it possible
784 to specify which logs are used for messages about ACL rejections.
785
786 3. There is a new authenticator called "dovecot". This is an interface to the
787 authentication facility of the Dovecot POP/IMAP server, which can support a
788 number of authentication methods.
789
790 4. The variable $message_headers_raw provides a concatenation of all the
791 messages's headers without any decoding. This is in contrast to
792 $message_headers, which does RFC2047 decoding on the header contents.
793
794 5. In a DNS black list, if two domain names, comma-separated, are given, the
795 second is used first to do an initial check, making use of any IP value
796 restrictions that are set. If there is a match, the first domain is used,
797 without any IP value restrictions, to get the TXT record.
798
799 6. All authenticators now have a server_condition option.
800
801 7. There is a new command-line option called -Mset. It is useful only in
802 conjunction with -be (that is, when testing string expansions). It must be
803 followed by a message id; Exim loads the given message from its spool
804 before doing the expansions.
805
806 8. Another similar new command-line option is called -bem. It operates like
807 -be except that it must be followed by the name of a file that contains a
808 message.
809
810 9. When an address is delayed because of a 4xx response to a RCPT command, it
811 is now the combination of sender and recipient that is delayed in
812 subsequent queue runs until its retry time is reached.
813
814 10. Unary negation and the bitwise logical operators and, or, xor, not, and
815 shift, have been added to the eval: and eval10: expansion items.
816
817 11. The variables $interface_address and $interface_port have been renamed
818 as $received_ip_address and $received_port, to make it clear that they
819 relate to message reception rather than delivery. (The old names remain
820 available for compatibility.)
821
822 12. The "message" modifier can now be used on "accept" and "discard" acl verbs
823 to vary the message that is sent when an SMTP command is accepted.
824
825
826 Version 4.63
827 ------------
828
829 1. There is a new Boolean option called filter_prepend_home for the redirect
830 router.
831
832 2. There is a new acl, set by acl_not_smtp_start, which is run right at the
833 start of receiving a non-SMTP message, before any of the message has been
834 read.
835
836 3. When an SMTP error message is specified in a "message" modifier in an ACL,
837 or in a :fail: or :defer: message in a redirect router, Exim now checks the
838 start of the message for an SMTP error code.
839
840 4. There is a new parameter for LDAP lookups called "referrals", which takes
841 one of the settings "follow" (the default) or "nofollow".
842
843 5. Version 20070721.2 of exipick now included, offering these new options:
844 --reverse
845 After all other sorting options have bee processed, reverse order
846 before displaying messages (-R is synonym).
847 --random
848 Randomize order of matching messages before displaying.
849 --size
850 Instead of displaying the matching messages, display the sum
851 of their sizes.
852 --sort <variable>[,<variable>...]
853 Before displaying matching messages, sort the messages according to
854 each messages value for each variable.
855 --not
856 Negate the value for every test (returns inverse output from the
857 same criteria without --not).
858
859
860 Version 4.62
861 ------------
862
863 1. The ${readsocket expansion item now supports Internet domain sockets as well
864 as Unix domain sockets. If the first argument begins "inet:", it must be of
865 the form "inet:host:port". The port is mandatory; it may be a number or the
866 name of a TCP port in /etc/services. The host may be a name, or it may be an
867 IP address. An ip address may optionally be enclosed in square brackets.
868 This is best for IPv6 addresses. For example:
869
870 ${readsocket{inet:[::1]:1234}{<request data>}...
871
872 Only a single host name may be given, but if looking it up yield more than
873 one IP address, they are each tried in turn until a connection is made. Once
874 a connection has been made, the behaviour is as for ${readsocket with a Unix
875 domain socket.
876
877 2. If a redirect router sets up file or pipe deliveries for more than one
878 incoming address, and the relevant transport has batch_max set greater than
879 one, a batch delivery now occurs.
880
881 3. The appendfile transport has a new option called maildirfolder_create_regex.
882 Its value is a regular expression. For a maildir delivery, this is matched
883 against the maildir directory; if it matches, Exim ensures that a
884 maildirfolder file is created alongside the new, cur, and tmp directories.
885
886
887 Version 4.61
888 ------------
889
890 The documentation is up-to-date for the 4.61 release. Major new features since
891 the 4.60 release are:
892
893 . An option called disable_ipv6, to disable the use of IPv6 completely.
894
895 . An increase in the number of ACL variables to 20 of each type.
896
897 . A change to use $auth1, $auth2, and $auth3 in authenticators instead of $1,
898 $2, $3, (though those are still set) because the numeric variables get used
899 for other things in complicated expansions.
900
901 . The default for rfc1413_query_timeout has been changed from 30s to 5s.
902
903 . It is possible to use setclassresources() on some BSD OS to control the
904 resources used in pipe deliveries.
905
906 . A new ACL modifier called add_header, which can be used with any verb.
907
908 . More errors are detectable in retry rules.
909
910 There are a number of other additions too.
911
912
913 Version 4.60
914 ------------
915
916 The documentation is up-to-date for the 4.60 release. Major new features since
917 the 4.50 release are:
918
919 . Support for SQLite.
920
921 . Support for IGNOREQUOTA in LMTP.
922
923 . Extensions to the "submission mode" features.
924
925 . Support for Client SMTP Authorization (CSA).
926
927 . Support for ratelimiting hosts and users.
928
929 . New expansion items to help with the BATV "prvs" scheme.
930
931 . A "match_ip" condition, that matches an IP address against a list.
932
933 There are many more minor changes.
934
935 ****