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
39 7. New command-line option -C for exiqgrep to specify alternate exim.conf
40 file when searching the queue.
42 8. EXPERIMENTAL_OCSP now supports GnuTLS also, if you have version 3.1.3
45 9. Support for DNSSEC on outbound connections.
47 10. New variables "tls_(in,out)_(our,peer)cert" and expansion item
48 "certextract" to extract fields from them. Hash operators md5 and sha1
49 work over them for generating fingerprints, and a new sha256 operator
56 1. New command-line option -bI:sieve will list all supported sieve extensions
57 of this Exim build on standard output, one per line.
58 ManageSieve (RFC 5804) providers managing scripts for use by Exim should
59 query this to establish the correct list to include in the protocol's
60 SIEVE capability line.
62 2. If the -n option is combined with the -bP option, then the name of an
63 emitted option is not output, only the value (if visible to you).
64 For instance, "exim -n -bP pid_file_path" should just emit a pathname
65 followed by a newline, and no other text.
67 3. When built with SUPPORT_TLS and USE_GNUTLS, the SMTP transport driver now
68 has a "tls_dh_min_bits" option, to set the minimum acceptable number of
69 bits in the Diffie-Hellman prime offered by a server (in DH ciphersuites)
70 acceptable for security. (Option accepted but ignored if using OpenSSL).
71 Defaults to 1024, the old value. May be lowered only to 512, or raised as
72 far as you like. Raising this may hinder TLS interoperability with other
73 sites and is not currently recommended. Lowering this will permit you to
74 establish a TLS session which is not as secure as you might like.
76 Unless you really know what you are doing, leave it alone.
78 4. If not built with DISABLE_DNSSEC, Exim now has the main option
79 dns_dnssec_ok; if set to 1 then Exim will initialise the resolver library
80 to send the DO flag to your recursive resolver. If you have a recursive
81 resolver, which can set the Authenticated Data (AD) flag in results, Exim
82 can now detect this. Exim does not perform validation itself, instead
83 relying upon a trusted path to the resolver.
85 Current status: work-in-progress; $sender_host_dnssec variable added.
87 5. DSCP support for outbound connections: on a transport using the smtp driver,
88 set "dscp = ef", for instance, to cause the connections to have the relevant
89 DSCP (IPv4 TOS or IPv6 TCLASS) value in the header.
91 Similarly for inbound connections, there is a new control modifier, dscp,
92 so "warn control = dscp/ef" in the connect ACL, or after authentication.
94 Supported values depend upon system libraries. "exim -bI:dscp" to list the
95 ones Exim knows of. You can also set a raw number 0..0x3F.
97 6. The -G command-line flag is no longer ignored; it is now equivalent to an
98 ACL setting "control = suppress_local_fixups". The -L command-line flag
99 is now accepted and forces use of syslog, with the provided tag as the
100 process name. A few other flags used by Sendmail are now accepted and
103 7. New cutthrough routing feature. Requested by a "control = cutthrough_delivery"
104 ACL modifier; works for single-recipient mails which are recieved on and
105 deliverable via SMTP. Using the connection made for a recipient verify,
106 if requested before the verify, or a new one made for the purpose while
107 the inbound connection is still active. The bulk of the mail item is copied
108 direct from the inbound socket to the outbound (as well as the spool file).
109 When the source notifies the end of data, the data acceptance by the destination
110 is negociated before the acceptance is sent to the source. If the destination
111 does not accept the mail item, for example due to content-scanning, the item
112 is not accepted from the source and therefore there is no need to generate
113 a bounce mail. This is of benefit when providing a secondary-MX service.
114 The downside is that delays are under the control of the ultimate destination
117 The Recieved-by: header on items delivered by cutthrough is generated
118 early in reception rather than at the end; this will affect any timestamp
119 included. The log line showing delivery is recorded before that showing
120 reception; it uses a new ">>" tag instead of "=>".
122 To support the feature, verify-callout connections can now use ESMTP and TLS.
123 The usual smtp transport options are honoured, plus a (new, default everything)
124 hosts_verify_avoid_tls.
126 New variable families named tls_in_cipher, tls_out_cipher etc. are introduced
127 for specific access to the information for each connection. The old names
128 are present for now but deprecated.
130 Not yet supported: IGNOREQUOTA, SIZE, PIPELINING.
132 8. New expansion operators ${listnamed:name} to get the content of a named list
133 and ${listcount:string} to count the items in a list.
135 9. New global option "gnutls_allow_auto_pkcs11", defaults false. The GnuTLS
136 rewrite in 4.80 combines with GnuTLS 2.12.0 or later, to autoload PKCS11
137 modules. For some situations this is desirable, but we expect admin in
138 those situations to know they want the feature. More commonly, it means
139 that GUI user modules get loaded and are broken by the setuid Exim being
140 unable to access files specified in environment variables and passed
141 through, thus breakage. So we explicitly inhibit the PKCS11 initialisation
142 unless this new option is set.
144 Some older OS's with earlier versions of GnuTLS might not have pkcs11 ability,
145 so have also added a build option which can be used to build Exim with GnuTLS
146 but without trying to use any kind of PKCS11 support. Uncomment this in the
149 AVOID_GNUTLS_PKCS11=yes
151 10. The "acl = name" condition on an ACL now supports optional arguments.
152 New expansion item "${acl {name}{arg}...}" and expansion condition
153 "acl {{name}{arg}...}" are added. In all cases up to nine arguments
154 can be used, appearing in $acl_arg1 to $acl_arg9 for the called ACL.
155 Variable $acl_narg contains the number of arguments. If the ACL sets
156 a "message =" value this becomes the result of the expansion item,
157 or the value of $value for the expansion condition. If the ACL returns
158 accept the expansion condition is true; if reject, false. A defer
159 return results in a forced fail.
161 11. Routers and transports can now have multiple headers_add and headers_remove
162 option lines. The concatenated list is used.
164 12. New ACL modifier "remove_header" can remove headers before message gets
165 handled by routers/transports.
167 13. New dnsdb lookup pseudo-type "a+". A sequence of "a6" (if configured),
168 "aaaa" and "a" lookups is done and the full set of results returned.
170 14. New expansion variable $headers_added with content from ACL add_header
171 modifier (but not yet added to messsage).
173 15. New 8bitmime status logging option for received messages. Log field "M8S".
175 16. New authenticated_sender logging option, adding to log field "A".
177 17. New expansion variables $router_name and $transport_name. Useful
178 particularly for debug_print as -bt commandline option does not
179 require privilege whereas -d does.
181 18. If built with EXPERIMENTAL_PRDR, per-recipient data responses per a
182 proposed extension to SMTP from Eric Hall.
184 19. The pipe transport has gained the force_command option, to allow
185 decorating commands from user .forward pipe aliases with prefix
186 wrappers, for instance.
188 20. Callout connections can now AUTH; the same controls as normal delivery
191 21. Support for DMARC, using opendmarc libs, can be enabled. It adds new
192 options: dmarc_forensic_sender, dmarc_history_file, and dmarc_tld_file.
193 It adds new expansion variables $dmarc_ar_header, $dmarc_status,
194 $dmarc_status_text, and $dmarc_used_domain. It adds a new acl modifier
195 dmarc_status. It adds new control flags dmarc_disable_verify and
196 dmarc_enable_forensic.
198 22. Add expansion variable $authenticated_fail_id, which is the username
199 provided to the authentication method which failed. It is available
200 for use in subsequent ACL processing (typically quit or notquit ACLs).
202 23. New ACL modifer "udpsend" can construct a UDP packet to send to a given
205 24. New ${hexquote:..string..} expansion operator converts non-printable
206 characters in the string to \xNN form.
208 25. Experimental TPDA (Transport Post Delivery Action) function added.
209 Patch provided by Axel Rau.
211 26. Experimental Redis lookup added. Patch provided by Warren Baker.
217 1. New authenticator driver, "gsasl". Server-only (at present).
218 This is a SASL interface, licensed under GPL, which can be found at
219 http://www.gnu.org/software/gsasl/.
220 This system does not provide sources of data for authentication, so
221 careful use needs to be made of the conditions in Exim.
223 2. New authenticator driver, "heimdal_gssapi". Server-only.
224 A replacement for using cyrus_sasl with Heimdal, now that $KRB5_KTNAME
225 is no longer honoured for setuid programs by Heimdal. Use the
226 "server_keytab" option to point to the keytab.
228 3. The "pkg-config" system can now be used when building Exim to reference
229 cflags and library information for lookups and authenticators, rather
230 than having to update "CFLAGS", "AUTH_LIBS", "LOOKUP_INCLUDE" and
231 "LOOKUP_LIBS" directly. Similarly for handling the TLS library support
232 without adjusting "TLS_INCLUDE" and "TLS_LIBS".
234 In addition, setting PCRE_CONFIG=yes will query the pcre-config tool to
235 find the headers and libraries for PCRE.
237 4. New expansion variable $tls_bits.
239 5. New lookup type, "dbmjz". Key is an Exim list, the elements of which will
240 be joined together with ASCII NUL characters to construct the key to pass
241 into the DBM library. Can be used with gsasl to access sasldb2 files as
244 6. OpenSSL now supports TLS1.1 and TLS1.2 with OpenSSL 1.0.1.
246 Avoid release 1.0.1a if you can. Note that the default value of
247 "openssl_options" is no longer "+dont_insert_empty_fragments", as that
248 increased susceptibility to attack. This may still have interoperability
249 implications for very old clients (see version 4.31 change 37) but
250 administrators can choose to make the trade-off themselves and restore
251 compatibility at the cost of session security.
253 7. Use of the new expansion variable $tls_sni in the main configuration option
254 tls_certificate will cause Exim to re-expand the option, if the client
255 sends the TLS Server Name Indication extension, to permit choosing a
256 different certificate; tls_privatekey will also be re-expanded. You must
257 still set these options to expand to valid files when $tls_sni is not set.
259 The SMTP Transport has gained the option tls_sni, which will set a hostname
260 for outbound TLS sessions, and set $tls_sni too.
262 A new log_selector, +tls_sni, has been added, to log received SNI values
263 for Exim as a server.
265 8. The existing "accept_8bitmime" option now defaults to true. This means
266 that Exim is deliberately not strictly RFC compliant. We're following
267 Dan Bernstein's advice in http://cr.yp.to/smtp/8bitmime.html by default.
268 Those who disagree, or know that they are talking to mail servers that,
269 even today, are not 8-bit clean, need to turn off this option.
271 9. Exim can now be started with -bw (with an optional timeout, given as
272 -bw<timespec>). With this, stdin at startup is a socket that is
273 already listening for connections. This has a more modern name of
274 "socket activation", but forcing the activated socket to fd 0. We're
275 interested in adding more support for modern variants.
277 10. ${eval } now uses 64-bit values on supporting platforms. A new "G" suffix
278 for numbers indicates multiplication by 1024^3.
280 11. The GnuTLS support has been revamped; the three options gnutls_require_kx,
281 gnutls_require_mac & gnutls_require_protocols are no longer supported.
282 tls_require_ciphers is now parsed by gnutls_priority_init(3) as a priority
283 string, documentation for which is at:
284 http://www.gnutls.org/manual/html_node/Priority-Strings.html
286 SNI support has been added to Exim's GnuTLS integration too.
288 For sufficiently recent GnuTLS libraries, ${randint:..} will now use
289 gnutls_rnd(), asking for GNUTLS_RND_NONCE level randomness.
291 12. With OpenSSL, if built with EXPERIMENTAL_OCSP, a new option tls_ocsp_file
292 is now available. If the contents of the file are valid, then Exim will
293 send that back in response to a TLS status request; this is OCSP Stapling.
294 Exim will not maintain the contents of the file in any way: administrators
295 are responsible for ensuring that it is up-to-date.
297 See "experimental-spec.txt" for more details.
299 13. ${lookup dnsdb{ }} supports now SPF record types. They are handled
300 identically to TXT record lookups.
302 14. New expansion variable $tod_epoch_l for higher-precision time.
304 15. New global option tls_dh_max_bits, defaulting to current value of NSS
305 hard-coded limit of DH ephemeral bits, to fix interop problems caused by
306 GnuTLS 2.12 library recommending a bit count higher than NSS supports.
308 16. tls_dhparam now used by both OpenSSL and GnuTLS, can be path or identifier.
309 Option can now be a path or an identifier for a standard prime.
310 If unset, we use the DH prime from section 2.2 of RFC 5114, "ike23".
311 Set to "historic" to get the old GnuTLS behaviour of auto-generated DH
314 17. SSLv2 now disabled by default in OpenSSL. (Never supported by GnuTLS).
315 Use "openssl_options -no_sslv2" to re-enable support, if your OpenSSL
316 install was not built with OPENSSL_NO_SSL2 ("no-ssl2").
322 1. New options for the ratelimit ACL condition: /count= and /unique=.
323 The /noupdate option has been replaced by a /readonly option.
325 2. The SMTP transport's protocol option may now be set to "smtps", to
326 use SSL-on-connect outbound.
328 3. New variable $av_failed, set true if the AV scanner deferred; ie, when
329 there is a problem talking to the AV scanner, or the AV scanner running.
331 4. New expansion conditions, "inlist" and "inlisti", which take simple lists
332 and check if the search item is a member of the list. This does not
333 support named lists, but does subject the list part to string expansion.
335 5. Unless the new EXPAND_LISTMATCH_RHS build option is set when Exim was
336 built, Exim no longer performs string expansion on the second string of
337 the match_* expansion conditions: "match_address", "match_domain",
338 "match_ip" & "match_local_part". Named lists can still be used.
344 1. The global option "dns_use_edns0" may be set to coerce EDNS0 usage on
345 or off in the resolver library.
351 1. In addition to the existing LDAP and LDAP/SSL ("ldaps") support, there
352 is now LDAP/TLS support, given sufficiently modern OpenLDAP client
353 libraries. The following global options have been added in support of
354 this: ldap_ca_cert_dir, ldap_ca_cert_file, ldap_cert_file, ldap_cert_key,
355 ldap_cipher_suite, ldap_require_cert, ldap_start_tls.
357 2. The pipe transport now takes a boolean option, "freeze_signal", default
358 false. When true, if the external delivery command exits on a signal then
359 Exim will freeze the message in the queue, instead of generating a bounce.
361 3. Log filenames may now use %M as an escape, instead of %D (still available).
362 The %M pattern expands to yyyymm, providing month-level resolution.
364 4. The $message_linecount variable is now updated for the maildir_tag option,
365 in the same way as $message_size, to reflect the real number of lines,
366 including any header additions or removals from transport.
368 5. When contacting a pool of SpamAssassin servers configured in spamd_address,
369 Exim now selects entries randomly, to better scale in a cluster setup.
375 1. SECURITY FIX: privilege escalation flaw fixed. On Linux (and only Linux)
376 the flaw permitted the Exim run-time user to cause root to append to
377 arbitrary files of the attacker's choosing, with the content based
378 on content supplied by the attacker.
380 2. Exim now supports loading some lookup types at run-time, using your
381 platform's dlopen() functionality. This has limited platform support
382 and the intention is not to support every variant, it's limited to
383 dlopen(). This permits the main Exim binary to not be linked against
384 all the libraries needed for all the lookup types.
390 NOTE: this version is not guaranteed backwards-compatible, please read the
391 items below carefully
393 1. A new main configuration option, "openssl_options", is available if Exim
394 is built with SSL support provided by OpenSSL. The option allows
395 administrators to specify OpenSSL options to be used on connections;
396 typically this is to set bug compatibility features which the OpenSSL
397 developers have not enabled by default. There may be security
398 consequences for certain options, so these should not be changed
401 2. A new pipe transport option, "permit_coredumps", may help with problem
402 diagnosis in some scenarios. Note that Exim is typically installed as
403 a setuid binary, which on most OSes will inhibit coredumps by default,
404 so that safety mechanism would have to be overridden for this option to
405 be able to take effect.
407 3. ClamAV 0.95 is now required for ClamAV support in Exim, unless
408 Local/Makefile sets: WITH_OLD_CLAMAV_STREAM=yes
409 Note that this switches Exim to use a new API ("INSTREAM") and a future
410 release of ClamAV will remove support for the old API ("STREAM").
412 The av_scanner option, when set to "clamd", now takes an optional third
413 part, "local", which causes Exim to pass a filename to ClamAV instead of
414 the file content. This is the same behaviour as when clamd is pointed at
415 a Unix-domain socket. For example:
417 av_scanner = clamd:192.0.2.3 1234:local
419 ClamAV's ExtendedDetectionInfo response format is now handled.
421 4. There is now a -bmalware option, restricted to admin users. This option
422 takes one parameter, a filename, and scans that file with Exim's
423 malware-scanning framework. This is intended purely as a debugging aid
424 to ensure that Exim's scanning is working, not to replace other tools.
425 Note that the ACL framework is not invoked, so if av_scanner references
426 ACL variables without a fallback then this will fail.
428 5. There is a new expansion operator, "reverse_ip", which will reverse IP
429 addresses; IPv4 into dotted quad, IPv6 into dotted nibble. Examples:
431 ${reverse_ip:192.0.2.4}
433 ${reverse_ip:2001:0db8:c42:9:1:abcd:192.0.2.3}
434 -> 3.0.2.0.0.0.0.c.d.c.b.a.1.0.0.0.9.0.0.0.2.4.c.0.8.b.d.0.1.0.0.2
436 6. There is a new ACL control called "debug", to enable debug logging.
437 This allows selective logging of certain incoming transactions within
438 production environments, with some care. It takes two options, "tag"
439 and "opts"; "tag" is included in the filename of the log and "opts"
440 is used as per the -d<options> command-line option. Examples, which
441 don't all make sense in all contexts:
444 control = debug/tag=.$sender_host_address
445 control = debug/opts=+expand+acl
446 control = debug/tag=.$message_exim_id/opts=+expand
448 7. It has always been implicit in the design and the documentation that
449 "the Exim user" is not root. src/EDITME said that using root was
450 "very strongly discouraged". This is not enough to keep people from
451 shooting themselves in the foot in days when many don't configure Exim
452 themselves but via package build managers. The security consequences of
453 running various bits of network code are severe if there should be bugs in
454 them. As such, the Exim user may no longer be root. If configured
455 statically, Exim will refuse to build. If configured as ref:user then Exim
456 will exit shortly after start-up. If you must shoot yourself in the foot,
457 then henceforth you will have to maintain your own local patches to strip
460 8. There is a new expansion condition, bool_lax{}. Where bool{} uses the ACL
461 condition logic to determine truth/failure and will fail to expand many
462 strings, bool_lax{} uses the router condition logic, where most strings
464 Note: bool{00} is false, bool_lax{00} is true.
466 9. Routers now support multiple "condition" tests.
468 10. There is now a runtime configuration option "tcp_wrappers_daemon_name".
469 Setting this allows an admin to define which entry in the tcpwrappers
470 config file will be used to control access to the daemon. This option
471 is only available when Exim is built with USE_TCP_WRAPPERS. The
472 default value is set at build time using the TCP_WRAPPERS_DAEMON_NAME
475 11. [POSSIBLE CONFIG BREAKAGE] The default value for system_filter_user is now
476 the Exim run-time user, instead of root.
478 12. [POSSIBLE CONFIG BREAKAGE] ALT_CONFIG_ROOT_ONLY is no longer optional and
479 is forced on. This is mitigated by the new build option
480 TRUSTED_CONFIG_LIST which defines a list of configuration files which
481 are trusted; one per line. If a config file is owned by root and matches
482 a pathname in the list, then it may be invoked by the Exim build-time
483 user without Exim relinquishing root privileges.
485 13. [POSSIBLE CONFIG BREAKAGE] The Exim user is no longer automatically
486 trusted to supply -D<Macro[=Value]> overrides on the command-line. Going
487 forward, we recommend using TRUSTED_CONFIG_LIST with shim configs that
488 include the main config. As a transition mechanism, we are temporarily
489 providing a work-around: the new build option WHITELIST_D_MACROS provides
490 a colon-separated list of macro names which may be overridden by the Exim
491 run-time user. The values of these macros are constrained to the regex
492 ^[A-Za-z0-9_/.-]*$ (which explicitly does allow for empty values).
498 1. TWO SECURITY FIXES: one relating to mail-spools which are globally
499 writable, the other to locking of MBX folders (not mbox).
501 2. MySQL stored procedures are now supported.
503 3. The dkim_domain transport option is now a list, not a single string, and
504 messages will be signed for each element in the list (discarding
507 4. The 4.70 release unexpectedly changed the behaviour of dnsdb TXT lookups
508 in the presence of multiple character strings within the RR. Prior to 4.70,
509 only the first string would be returned. The dnsdb lookup now, by default,
510 preserves the pre-4.70 semantics, but also now takes an extended output
511 separator specification. The separator can be followed by a semicolon, to
512 concatenate the individual text strings together with no join character,
513 or by a comma and a second separator character, in which case the text
514 strings within a TXT record are joined on that second character.
515 Administrators are reminded that DNS provides no ordering guarantees
516 between multiple records in an RRset. For example:
518 foo.example. IN TXT "a" "b" "c"
519 foo.example. IN TXT "d" "e" "f"
521 ${lookup dnsdb{>/ txt=foo.example}} -> "a/d"
522 ${lookup dnsdb{>/; txt=foo.example}} -> "def/abc"
523 ${lookup dnsdb{>/,+ txt=foo.example}} -> "a+b+c/d+e+f"
529 1. Native DKIM support without an external library.
530 (Note that if no action to prevent it is taken, a straight upgrade will
531 result in DKIM verification of all signed incoming emails. See spec
532 for details on conditionally disabling)
534 2. Experimental DCC support via dccifd (contributed by Wolfgang Breyha).
536 3. There is now a bool{} expansion condition which maps certain strings to
537 true/false condition values (most likely of use in conjunction with the
538 and{} expansion operator).
540 4. The $spam_score, $spam_bar and $spam_report variables are now available
543 5. exim -bP now supports "macros", "macro_list" or "macro MACRO_NAME" as
544 options, provided that Exim is invoked by an admin_user.
546 6. There is a new option gnutls_compat_mode, when linked against GnuTLS,
547 which increases compatibility with older clients at the cost of decreased
548 security. Don't set this unless you need to support such clients.
550 7. There is a new expansion operator, ${randint:...} which will produce a
551 "random" number less than the supplied integer. This randomness is
552 not guaranteed to be cryptographically strong, but depending upon how
553 Exim was built may be better than the most naive schemes.
555 8. Exim now explicitly ensures that SHA256 is available when linked against
558 9. The transport_filter_timeout option now applies to SMTP transports too.
564 1. Preliminary DKIM support in Experimental.
570 1. The body_linecount and body_zerocount C variables are now exported in the
573 2. When a dnslists lookup succeeds, the key that was looked up is now placed
574 in $dnslist_matched. When the key is an IP address, it is not reversed in
575 this variable (though it is, of course, in the actual lookup). In simple
578 deny dnslists = spamhaus.example
580 the key is also available in another variable (in this case,
581 $sender_host_address). In more complicated cases, however, this is not
582 true. For example, using a data lookup might generate a dnslists lookup
585 deny dnslists = spamhaus.example/<|192.168.1.2|192.168.6.7|...
587 If this condition succeeds, the value in $dnslist_matched might be
588 192.168.6.7 (for example).
590 3. Authenticators now have a client_condition option. When Exim is running as
591 a client, it skips an authenticator whose client_condition expansion yields
592 "0", "no", or "false". This can be used, for example, to skip plain text
593 authenticators when the connection is not encrypted by a setting such as:
595 client_condition = ${if !eq{$tls_cipher}{}}
597 Note that the 4.67 documentation states that $tls_cipher contains the
598 cipher used for incoming messages. In fact, during SMTP delivery, it
599 contains the cipher used for the delivery. The same is true for
602 4. There is now a -Mvc <message-id> option, which outputs a copy of the
603 message to the standard output, in RFC 2822 format. The option can be used
604 only by an admin user.
606 5. There is now a /noupdate option for the ratelimit ACL condition. It
607 computes the rate and checks the limit as normal, but it does not update
608 the saved data. This means that, in relevant ACLs, it is possible to lookup
609 the existence of a specified (or auto-generated) ratelimit key without
610 incrementing the ratelimit counter for that key.
612 In order for this to be useful, another ACL entry must set the rate
613 for the same key somewhere (otherwise it will always be zero).
618 # Read the rate; if it doesn't exist or is below the maximum
620 deny ratelimit = 100 / 5m / strict / noupdate
621 log_message = RATE: $sender_rate / $sender_rate_period \
622 (max $sender_rate_limit)
624 [... some other logic and tests...]
626 warn ratelimit = 100 / 5m / strict / per_cmd
627 log_message = RATE UPDATE: $sender_rate / $sender_rate_period \
628 (max $sender_rate_limit)
629 condition = ${if le{$sender_rate}{$sender_rate_limit}}
633 6. The variable $max_received_linelength contains the number of bytes in the
634 longest line that was received as part of the message, not counting the
635 line termination character(s).
637 7. Host lists can now include +ignore_defer and +include_defer, analagous to
638 +ignore_unknown and +include_unknown. These options should be used with
639 care, probably only in non-critical host lists such as whitelists.
641 8. There's a new option called queue_only_load_latch, which defaults true.
642 If set false when queue_only_load is greater than zero, Exim re-evaluates
643 the load for each incoming message in an SMTP session. Otherwise, once one
644 message is queued, the remainder are also.
646 9. There is a new ACL, specified by acl_smtp_notquit, which is run in most
647 cases when an SMTP session ends without sending QUIT. However, when Exim
648 itself is is bad trouble, such as being unable to write to its log files,
649 this ACL is not run, because it might try to do things (such as write to
650 log files) that make the situation even worse.
652 Like the QUIT ACL, this new ACL is provided to make it possible to gather
653 statistics. Whatever it returns (accept or deny) is immaterial. The "delay"
654 modifier is forbidden in this ACL.
656 When the NOTQUIT ACL is running, the variable $smtp_notquit_reason is set
657 to a string that indicates the reason for the termination of the SMTP
658 connection. The possible values are:
660 acl-drop Another ACL issued a "drop" command
661 bad-commands Too many unknown or non-mail commands
662 command-timeout Timeout while reading SMTP commands
663 connection-lost The SMTP connection has been lost
664 data-timeout Timeout while reading message data
665 local-scan-error The local_scan() function crashed
666 local-scan-timeout The local_scan() function timed out
667 signal-exit SIGTERM or SIGINT
668 synchronization-error SMTP synchronization error
669 tls-failed TLS failed to start
671 In most cases when an SMTP connection is closed without having received
672 QUIT, Exim sends an SMTP response message before actually closing the
673 connection. With the exception of acl-drop, the default message can be
674 overridden by the "message" modifier in the NOTQUIT ACL. In the case of a
675 "drop" verb in another ACL, it is the message from the other ACL that is
678 10. For MySQL and PostgreSQL lookups, it is now possible to specify a list of
679 servers with individual queries. This is done by starting the query with
680 "servers=x:y:z;", where each item in the list may take one of two forms:
682 (1) If it is just a host name, the appropriate global option (mysql_servers
683 or pgsql_servers) is searched for a host of the same name, and the
684 remaining parameters (database, user, password) are taken from there.
686 (2) If it contains any slashes, it is taken as a complete parameter set.
688 The list of servers is used in exactly the same was as the global list.
689 Once a connection to a server has happened and a query has been
690 successfully executed, processing of the lookup ceases.
692 This feature is intended for use in master/slave situations where updates
693 are occurring, and one wants to update a master rather than a slave. If the
694 masters are in the list for reading, you might have:
696 mysql_servers = slave1/db/name/pw:slave2/db/name/pw:master/db/name/pw
698 In an updating lookup, you could then write
700 ${lookup mysql{servers=master; UPDATE ...}
702 If, on the other hand, the master is not to be used for reading lookups:
704 pgsql_servers = slave1/db/name/pw:slave2/db/name/pw
706 you can still update the master by
708 ${lookup pgsql{servers=master/db/name/pw; UPDATE ...}
710 11. The message_body_newlines option (default FALSE, for backwards
711 compatibility) can be used to control whether newlines are present in
712 $message_body and $message_body_end. If it is FALSE, they are replaced by
719 1. There is a new log selector called smtp_no_mail, which is not included in
720 the default setting. When it is set, a line is written to the main log
721 whenever an accepted SMTP connection terminates without having issued a
724 2. When an item in a dnslists list is followed by = and & and a list of IP
725 addresses, the behaviour was not clear when the lookup returned more than
726 one IP address. This has been solved by the addition of == and =& for "all"
727 rather than the default "any" matching.
729 3. Up till now, the only control over which cipher suites GnuTLS uses has been
730 for the cipher algorithms. New options have been added to allow some of the
731 other parameters to be varied.
733 4. There is a new compile-time option called ENABLE_DISABLE_FSYNC. When it is
734 set, Exim compiles a runtime option called disable_fsync.
736 5. There is a new variable called $smtp_count_at_connection_start.
738 6. There's a new control called no_pipelining.
740 7. There are two new variables called $sending_ip_address and $sending_port.
741 These are set whenever an SMTP connection to another host has been set up.
743 8. The expansion of the helo_data option in the smtp transport now happens
744 after the connection to the server has been made.
746 9. There is a new expansion operator ${rfc2047d: that decodes strings that
747 are encoded as per RFC 2047.
749 10. There is a new log selector called "pid", which causes the current process
750 id to be added to every log line, in square brackets, immediately after the
753 11. Exim has been modified so that it flushes SMTP output before implementing
754 a delay in an ACL. It also flushes the output before performing a callout,
755 as this can take a substantial time. These behaviours can be disabled by
756 obeying control = no_delay_flush or control = no_callout_flush,
757 respectively, at some earlier stage of the connection.
759 12. There are two new expansion conditions that iterate over a list. They are
760 called forany and forall.
762 13. There's a new global option called dsn_from that can be used to vary the
763 contents of From: lines in bounces and other automatically generated
764 messages ("delivery status notifications" - hence the name of the option).
766 14. The smtp transport has a new option called hosts_avoid_pipelining.
768 15. By default, exigrep does case-insensitive matches. There is now a -I option
769 that makes it case-sensitive.
771 16. A number of new features ("addresses", "map", "filter", and "reduce") have
772 been added to string expansions to make it easier to process lists of
773 items, typically addresses.
775 17. There's a new ACL modifier called "continue". It does nothing of itself,
776 and processing of the ACL always continues with the next condition or
777 modifier. It is provided so that the side effects of expanding its argument
780 18. It is now possible to use newline and other control characters (those with
781 values less than 32, plus DEL) as separators in lists.
783 19. The exigrep utility now has a -v option, which inverts the matching
786 20. The host_find_failed option in the manualroute router can now be set to
793 No new features were added to 4.66.
799 No new features were added to 4.65.
805 1. ACL variables can now be given arbitrary names, as long as they start with
806 "acl_c" or "acl_m" (for connection variables and message variables), are at
807 least six characters long, with the sixth character being either a digit or
810 2. There is a new ACL modifier called log_reject_target. It makes it possible
811 to specify which logs are used for messages about ACL rejections.
813 3. There is a new authenticator called "dovecot". This is an interface to the
814 authentication facility of the Dovecot POP/IMAP server, which can support a
815 number of authentication methods.
817 4. The variable $message_headers_raw provides a concatenation of all the
818 messages's headers without any decoding. This is in contrast to
819 $message_headers, which does RFC2047 decoding on the header contents.
821 5. In a DNS black list, if two domain names, comma-separated, are given, the
822 second is used first to do an initial check, making use of any IP value
823 restrictions that are set. If there is a match, the first domain is used,
824 without any IP value restrictions, to get the TXT record.
826 6. All authenticators now have a server_condition option.
828 7. There is a new command-line option called -Mset. It is useful only in
829 conjunction with -be (that is, when testing string expansions). It must be
830 followed by a message id; Exim loads the given message from its spool
831 before doing the expansions.
833 8. Another similar new command-line option is called -bem. It operates like
834 -be except that it must be followed by the name of a file that contains a
837 9. When an address is delayed because of a 4xx response to a RCPT command, it
838 is now the combination of sender and recipient that is delayed in
839 subsequent queue runs until its retry time is reached.
841 10. Unary negation and the bitwise logical operators and, or, xor, not, and
842 shift, have been added to the eval: and eval10: expansion items.
844 11. The variables $interface_address and $interface_port have been renamed
845 as $received_ip_address and $received_port, to make it clear that they
846 relate to message reception rather than delivery. (The old names remain
847 available for compatibility.)
849 12. The "message" modifier can now be used on "accept" and "discard" acl verbs
850 to vary the message that is sent when an SMTP command is accepted.
856 1. There is a new Boolean option called filter_prepend_home for the redirect
859 2. There is a new acl, set by acl_not_smtp_start, which is run right at the
860 start of receiving a non-SMTP message, before any of the message has been
863 3. When an SMTP error message is specified in a "message" modifier in an ACL,
864 or in a :fail: or :defer: message in a redirect router, Exim now checks the
865 start of the message for an SMTP error code.
867 4. There is a new parameter for LDAP lookups called "referrals", which takes
868 one of the settings "follow" (the default) or "nofollow".
870 5. Version 20070721.2 of exipick now included, offering these new options:
872 After all other sorting options have bee processed, reverse order
873 before displaying messages (-R is synonym).
875 Randomize order of matching messages before displaying.
877 Instead of displaying the matching messages, display the sum
879 --sort <variable>[,<variable>...]
880 Before displaying matching messages, sort the messages according to
881 each messages value for each variable.
883 Negate the value for every test (returns inverse output from the
884 same criteria without --not).
890 1. The ${readsocket expansion item now supports Internet domain sockets as well
891 as Unix domain sockets. If the first argument begins "inet:", it must be of
892 the form "inet:host:port". The port is mandatory; it may be a number or the
893 name of a TCP port in /etc/services. The host may be a name, or it may be an
894 IP address. An ip address may optionally be enclosed in square brackets.
895 This is best for IPv6 addresses. For example:
897 ${readsocket{inet:[::1]:1234}{<request data>}...
899 Only a single host name may be given, but if looking it up yield more than
900 one IP address, they are each tried in turn until a connection is made. Once
901 a connection has been made, the behaviour is as for ${readsocket with a Unix
904 2. If a redirect router sets up file or pipe deliveries for more than one
905 incoming address, and the relevant transport has batch_max set greater than
906 one, a batch delivery now occurs.
908 3. The appendfile transport has a new option called maildirfolder_create_regex.
909 Its value is a regular expression. For a maildir delivery, this is matched
910 against the maildir directory; if it matches, Exim ensures that a
911 maildirfolder file is created alongside the new, cur, and tmp directories.
917 The documentation is up-to-date for the 4.61 release. Major new features since
918 the 4.60 release are:
920 . An option called disable_ipv6, to disable the use of IPv6 completely.
922 . An increase in the number of ACL variables to 20 of each type.
924 . A change to use $auth1, $auth2, and $auth3 in authenticators instead of $1,
925 $2, $3, (though those are still set) because the numeric variables get used
926 for other things in complicated expansions.
928 . The default for rfc1413_query_timeout has been changed from 30s to 5s.
930 . It is possible to use setclassresources() on some BSD OS to control the
931 resources used in pipe deliveries.
933 . A new ACL modifier called add_header, which can be used with any verb.
935 . More errors are detectable in retry rules.
937 There are a number of other additions too.
943 The documentation is up-to-date for the 4.60 release. Major new features since
944 the 4.50 release are:
946 . Support for SQLite.
948 . Support for IGNOREQUOTA in LMTP.
950 . Extensions to the "submission mode" features.
952 . Support for Client SMTP Authorization (CSA).
954 . Support for ratelimiting hosts and users.
956 . New expansion items to help with the BATV "prvs" scheme.
958 . A "match_ip" condition, that matches an IP address against a list.
960 There are many more minor changes.
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