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