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. Support for using the system standard CA bundle.
14 2. New expansion items $config_file, $config_dir, containing the file
15 and directory name of the main configuration file. Also $exim_version.
17 3. New "malware=" support for Avast.
19 4. New "spam=" variant option for Rspamd.
21 5. Assorted options on malware= and spam= scanners.
23 6. A commandline option to write a comment into the logfile.
25 7. If built with EXPERIMENTAL_SOCKS feature enabled, the smtp transport can
26 be configured to make connections via socks5 proxies.
28 8. If built with EXPERIMENTAL_INTERNATIONAL, support is included for
29 the transmission of UTF-8 envelope addresses.
35 1. If built with EXPERIMENTAL_DANE feature enabled, Exim will follow the
36 DANE smtp draft to assess a secure chain of trust of the certificate
37 used to establish the TLS connection based on a TLSA record in the
40 2. The EXPERIMENTAL_TPDA feature has been renamed to EXPERIMENTAL_EVENT
41 and several new events have been created. The reason is because it has
42 been expanded beyond just firing events during the transport phase. Any
43 existing TPDA transport options will have to be rewritten to use a new
44 $event_name expansion variable in a condition. Refer to the
45 experimental-spec.txt for details and examples.
47 3. The EXPERIMENTAL_CERTNAMES features is an enhancement to verify that
48 server certs used for TLS match the result of the MX lookup. It does
49 not use the same mechanism as DANE.
59 1. If built with the EXPERIMENTAL_PROXY feature enabled, Exim can be
60 configured to expect an initial header from a proxy that will make the
61 actual external source IP:host be used in exim instead of the IP of the
62 proxy that is connecting to it.
64 2. New verify option header_names_ascii, which will check to make sure
65 there are no non-ASCII characters in header names. Exim itself handles
66 those non-ASCII characters, but downstream apps may not, so Exim can
67 detect and reject if those characters are present.
69 3. New expansion operator ${utf8clean:string} to replace malformed UTF8
70 codepoints with valid ones.
72 4. New malware type "sock". Talks over a Unix or TCP socket, sending one
73 command line and matching a regex against the return data for trigger
74 and a second regex to extract malware_name. The mail spoolfile name can
75 be included in the command line.
77 5. The smtp transport now supports options "tls_verify_hosts" and
78 "tls_try_verify_hosts". If either is set the certificate verification
79 is split from the encryption operation. The default remains that a failed
80 verification cancels the encryption.
82 6. New SERVERS override of default ldap server list. In the ACLs, an ldap
83 lookup can now set a list of servers to use that is different from the
86 7. New command-line option -C for exiqgrep to specify alternate exim.conf
87 file when searching the queue.
89 8. OCSP now supports GnuTLS also, if you have version 3.1.3 or later of that.
91 9. Support for DNSSEC on outbound connections.
93 10. New variables "tls_(in,out)_(our,peer)cert" and expansion item
94 "certextract" to extract fields from them. Hash operators md5 and sha1
95 work over them for generating fingerprints, and a new sha256 operator
98 11. PRDR is now supported dy default.
100 12. OCSP stapling is now supported by default.
102 13. If built with the EXPERIMENTAL_DSN feature enabled, Exim will output
103 Delivery Status Notification messages in MIME format, and negociate
104 DSN features per RFC 3461.
110 1. New command-line option -bI:sieve will list all supported sieve extensions
111 of this Exim build on standard output, one per line.
112 ManageSieve (RFC 5804) providers managing scripts for use by Exim should
113 query this to establish the correct list to include in the protocol's
114 SIEVE capability line.
116 2. If the -n option is combined with the -bP option, then the name of an
117 emitted option is not output, only the value (if visible to you).
118 For instance, "exim -n -bP pid_file_path" should just emit a pathname
119 followed by a newline, and no other text.
121 3. When built with SUPPORT_TLS and USE_GNUTLS, the SMTP transport driver now
122 has a "tls_dh_min_bits" option, to set the minimum acceptable number of
123 bits in the Diffie-Hellman prime offered by a server (in DH ciphersuites)
124 acceptable for security. (Option accepted but ignored if using OpenSSL).
125 Defaults to 1024, the old value. May be lowered only to 512, or raised as
126 far as you like. Raising this may hinder TLS interoperability with other
127 sites and is not currently recommended. Lowering this will permit you to
128 establish a TLS session which is not as secure as you might like.
130 Unless you really know what you are doing, leave it alone.
132 4. If not built with DISABLE_DNSSEC, Exim now has the main option
133 dns_dnssec_ok; if set to 1 then Exim will initialise the resolver library
134 to send the DO flag to your recursive resolver. If you have a recursive
135 resolver, which can set the Authenticated Data (AD) flag in results, Exim
136 can now detect this. Exim does not perform validation itself, instead
137 relying upon a trusted path to the resolver.
139 Current status: work-in-progress; $sender_host_dnssec variable added.
141 5. DSCP support for outbound connections: on a transport using the smtp driver,
142 set "dscp = ef", for instance, to cause the connections to have the relevant
143 DSCP (IPv4 TOS or IPv6 TCLASS) value in the header.
145 Similarly for inbound connections, there is a new control modifier, dscp,
146 so "warn control = dscp/ef" in the connect ACL, or after authentication.
148 Supported values depend upon system libraries. "exim -bI:dscp" to list the
149 ones Exim knows of. You can also set a raw number 0..0x3F.
151 6. The -G command-line flag is no longer ignored; it is now equivalent to an
152 ACL setting "control = suppress_local_fixups". The -L command-line flag
153 is now accepted and forces use of syslog, with the provided tag as the
154 process name. A few other flags used by Sendmail are now accepted and
157 7. New cutthrough routing feature. Requested by a "control = cutthrough_delivery"
158 ACL modifier; works for single-recipient mails which are recieved on and
159 deliverable via SMTP. Using the connection made for a recipient verify,
160 if requested before the verify, or a new one made for the purpose while
161 the inbound connection is still active. The bulk of the mail item is copied
162 direct from the inbound socket to the outbound (as well as the spool file).
163 When the source notifies the end of data, the data acceptance by the destination
164 is negociated before the acceptance is sent to the source. If the destination
165 does not accept the mail item, for example due to content-scanning, the item
166 is not accepted from the source and therefore there is no need to generate
167 a bounce mail. This is of benefit when providing a secondary-MX service.
168 The downside is that delays are under the control of the ultimate destination
171 The Recieved-by: header on items delivered by cutthrough is generated
172 early in reception rather than at the end; this will affect any timestamp
173 included. The log line showing delivery is recorded before that showing
174 reception; it uses a new ">>" tag instead of "=>".
176 To support the feature, verify-callout connections can now use ESMTP and TLS.
177 The usual smtp transport options are honoured, plus a (new, default everything)
178 hosts_verify_avoid_tls.
180 New variable families named tls_in_cipher, tls_out_cipher etc. are introduced
181 for specific access to the information for each connection. The old names
182 are present for now but deprecated.
184 Not yet supported: IGNOREQUOTA, SIZE, PIPELINING.
186 8. New expansion operators ${listnamed:name} to get the content of a named list
187 and ${listcount:string} to count the items in a list.
189 9. New global option "gnutls_allow_auto_pkcs11", defaults false. The GnuTLS
190 rewrite in 4.80 combines with GnuTLS 2.12.0 or later, to autoload PKCS11
191 modules. For some situations this is desirable, but we expect admin in
192 those situations to know they want the feature. More commonly, it means
193 that GUI user modules get loaded and are broken by the setuid Exim being
194 unable to access files specified in environment variables and passed
195 through, thus breakage. So we explicitly inhibit the PKCS11 initialisation
196 unless this new option is set.
198 Some older OS's with earlier versions of GnuTLS might not have pkcs11 ability,
199 so have also added a build option which can be used to build Exim with GnuTLS
200 but without trying to use any kind of PKCS11 support. Uncomment this in the
203 AVOID_GNUTLS_PKCS11=yes
205 10. The "acl = name" condition on an ACL now supports optional arguments.
206 New expansion item "${acl {name}{arg}...}" and expansion condition
207 "acl {{name}{arg}...}" are added. In all cases up to nine arguments
208 can be used, appearing in $acl_arg1 to $acl_arg9 for the called ACL.
209 Variable $acl_narg contains the number of arguments. If the ACL sets
210 a "message =" value this becomes the result of the expansion item,
211 or the value of $value for the expansion condition. If the ACL returns
212 accept the expansion condition is true; if reject, false. A defer
213 return results in a forced fail.
215 11. Routers and transports can now have multiple headers_add and headers_remove
216 option lines. The concatenated list is used.
218 12. New ACL modifier "remove_header" can remove headers before message gets
219 handled by routers/transports.
221 13. New dnsdb lookup pseudo-type "a+". A sequence of "a6" (if configured),
222 "aaaa" and "a" lookups is done and the full set of results returned.
224 14. New expansion variable $headers_added with content from ACL add_header
225 modifier (but not yet added to messsage).
227 15. New 8bitmime status logging option for received messages. Log field "M8S".
229 16. New authenticated_sender logging option, adding to log field "A".
231 17. New expansion variables $router_name and $transport_name. Useful
232 particularly for debug_print as -bt commandline option does not
233 require privilege whereas -d does.
235 18. If built with EXPERIMENTAL_PRDR, per-recipient data responses per a
236 proposed extension to SMTP from Eric Hall.
238 19. The pipe transport has gained the force_command option, to allow
239 decorating commands from user .forward pipe aliases with prefix
240 wrappers, for instance.
242 20. Callout connections can now AUTH; the same controls as normal delivery
245 21. Support for DMARC, using opendmarc libs, can be enabled. It adds new
246 options: dmarc_forensic_sender, dmarc_history_file, and dmarc_tld_file.
247 It adds new expansion variables $dmarc_ar_header, $dmarc_status,
248 $dmarc_status_text, and $dmarc_used_domain. It adds a new acl modifier
249 dmarc_status. It adds new control flags dmarc_disable_verify and
250 dmarc_enable_forensic.
252 22. Add expansion variable $authenticated_fail_id, which is the username
253 provided to the authentication method which failed. It is available
254 for use in subsequent ACL processing (typically quit or notquit ACLs).
256 23. New ACL modifer "udpsend" can construct a UDP packet to send to a given
259 24. New ${hexquote:..string..} expansion operator converts non-printable
260 characters in the string to \xNN form.
262 25. Experimental TPDA (Transport Post Delivery Action) function added.
263 Patch provided by Axel Rau.
265 26. Experimental Redis lookup added. Patch provided by Warren Baker.
271 1. New authenticator driver, "gsasl". Server-only (at present).
272 This is a SASL interface, licensed under GPL, which can be found at
273 http://www.gnu.org/software/gsasl/.
274 This system does not provide sources of data for authentication, so
275 careful use needs to be made of the conditions in Exim.
277 2. New authenticator driver, "heimdal_gssapi". Server-only.
278 A replacement for using cyrus_sasl with Heimdal, now that $KRB5_KTNAME
279 is no longer honoured for setuid programs by Heimdal. Use the
280 "server_keytab" option to point to the keytab.
282 3. The "pkg-config" system can now be used when building Exim to reference
283 cflags and library information for lookups and authenticators, rather
284 than having to update "CFLAGS", "AUTH_LIBS", "LOOKUP_INCLUDE" and
285 "LOOKUP_LIBS" directly. Similarly for handling the TLS library support
286 without adjusting "TLS_INCLUDE" and "TLS_LIBS".
288 In addition, setting PCRE_CONFIG=yes will query the pcre-config tool to
289 find the headers and libraries for PCRE.
291 4. New expansion variable $tls_bits.
293 5. New lookup type, "dbmjz". Key is an Exim list, the elements of which will
294 be joined together with ASCII NUL characters to construct the key to pass
295 into the DBM library. Can be used with gsasl to access sasldb2 files as
298 6. OpenSSL now supports TLS1.1 and TLS1.2 with OpenSSL 1.0.1.
300 Avoid release 1.0.1a if you can. Note that the default value of
301 "openssl_options" is no longer "+dont_insert_empty_fragments", as that
302 increased susceptibility to attack. This may still have interoperability
303 implications for very old clients (see version 4.31 change 37) but
304 administrators can choose to make the trade-off themselves and restore
305 compatibility at the cost of session security.
307 7. Use of the new expansion variable $tls_sni in the main configuration option
308 tls_certificate will cause Exim to re-expand the option, if the client
309 sends the TLS Server Name Indication extension, to permit choosing a
310 different certificate; tls_privatekey will also be re-expanded. You must
311 still set these options to expand to valid files when $tls_sni is not set.
313 The SMTP Transport has gained the option tls_sni, which will set a hostname
314 for outbound TLS sessions, and set $tls_sni too.
316 A new log_selector, +tls_sni, has been added, to log received SNI values
317 for Exim as a server.
319 8. The existing "accept_8bitmime" option now defaults to true. This means
320 that Exim is deliberately not strictly RFC compliant. We're following
321 Dan Bernstein's advice in http://cr.yp.to/smtp/8bitmime.html by default.
322 Those who disagree, or know that they are talking to mail servers that,
323 even today, are not 8-bit clean, need to turn off this option.
325 9. Exim can now be started with -bw (with an optional timeout, given as
326 -bw<timespec>). With this, stdin at startup is a socket that is
327 already listening for connections. This has a more modern name of
328 "socket activation", but forcing the activated socket to fd 0. We're
329 interested in adding more support for modern variants.
331 10. ${eval } now uses 64-bit values on supporting platforms. A new "G" suffix
332 for numbers indicates multiplication by 1024^3.
334 11. The GnuTLS support has been revamped; the three options gnutls_require_kx,
335 gnutls_require_mac & gnutls_require_protocols are no longer supported.
336 tls_require_ciphers is now parsed by gnutls_priority_init(3) as a priority
337 string, documentation for which is at:
338 http://www.gnutls.org/manual/html_node/Priority-Strings.html
340 SNI support has been added to Exim's GnuTLS integration too.
342 For sufficiently recent GnuTLS libraries, ${randint:..} will now use
343 gnutls_rnd(), asking for GNUTLS_RND_NONCE level randomness.
345 12. With OpenSSL, if built with EXPERIMENTAL_OCSP, a new option tls_ocsp_file
346 is now available. If the contents of the file are valid, then Exim will
347 send that back in response to a TLS status request; this is OCSP Stapling.
348 Exim will not maintain the contents of the file in any way: administrators
349 are responsible for ensuring that it is up-to-date.
351 See "experimental-spec.txt" for more details.
353 13. ${lookup dnsdb{ }} supports now SPF record types. They are handled
354 identically to TXT record lookups.
356 14. New expansion variable $tod_epoch_l for higher-precision time.
358 15. New global option tls_dh_max_bits, defaulting to current value of NSS
359 hard-coded limit of DH ephemeral bits, to fix interop problems caused by
360 GnuTLS 2.12 library recommending a bit count higher than NSS supports.
362 16. tls_dhparam now used by both OpenSSL and GnuTLS, can be path or identifier.
363 Option can now be a path or an identifier for a standard prime.
364 If unset, we use the DH prime from section 2.2 of RFC 5114, "ike23".
365 Set to "historic" to get the old GnuTLS behaviour of auto-generated DH
368 17. SSLv2 now disabled by default in OpenSSL. (Never supported by GnuTLS).
369 Use "openssl_options -no_sslv2" to re-enable support, if your OpenSSL
370 install was not built with OPENSSL_NO_SSL2 ("no-ssl2").
376 1. New options for the ratelimit ACL condition: /count= and /unique=.
377 The /noupdate option has been replaced by a /readonly option.
379 2. The SMTP transport's protocol option may now be set to "smtps", to
380 use SSL-on-connect outbound.
382 3. New variable $av_failed, set true if the AV scanner deferred; ie, when
383 there is a problem talking to the AV scanner, or the AV scanner running.
385 4. New expansion conditions, "inlist" and "inlisti", which take simple lists
386 and check if the search item is a member of the list. This does not
387 support named lists, but does subject the list part to string expansion.
389 5. Unless the new EXPAND_LISTMATCH_RHS build option is set when Exim was
390 built, Exim no longer performs string expansion on the second string of
391 the match_* expansion conditions: "match_address", "match_domain",
392 "match_ip" & "match_local_part". Named lists can still be used.
398 1. The global option "dns_use_edns0" may be set to coerce EDNS0 usage on
399 or off in the resolver library.
405 1. In addition to the existing LDAP and LDAP/SSL ("ldaps") support, there
406 is now LDAP/TLS support, given sufficiently modern OpenLDAP client
407 libraries. The following global options have been added in support of
408 this: ldap_ca_cert_dir, ldap_ca_cert_file, ldap_cert_file, ldap_cert_key,
409 ldap_cipher_suite, ldap_require_cert, ldap_start_tls.
411 2. The pipe transport now takes a boolean option, "freeze_signal", default
412 false. When true, if the external delivery command exits on a signal then
413 Exim will freeze the message in the queue, instead of generating a bounce.
415 3. Log filenames may now use %M as an escape, instead of %D (still available).
416 The %M pattern expands to yyyymm, providing month-level resolution.
418 4. The $message_linecount variable is now updated for the maildir_tag option,
419 in the same way as $message_size, to reflect the real number of lines,
420 including any header additions or removals from transport.
422 5. When contacting a pool of SpamAssassin servers configured in spamd_address,
423 Exim now selects entries randomly, to better scale in a cluster setup.
429 1. SECURITY FIX: privilege escalation flaw fixed. On Linux (and only Linux)
430 the flaw permitted the Exim run-time user to cause root to append to
431 arbitrary files of the attacker's choosing, with the content based
432 on content supplied by the attacker.
434 2. Exim now supports loading some lookup types at run-time, using your
435 platform's dlopen() functionality. This has limited platform support
436 and the intention is not to support every variant, it's limited to
437 dlopen(). This permits the main Exim binary to not be linked against
438 all the libraries needed for all the lookup types.
444 NOTE: this version is not guaranteed backwards-compatible, please read the
445 items below carefully
447 1. A new main configuration option, "openssl_options", is available if Exim
448 is built with SSL support provided by OpenSSL. The option allows
449 administrators to specify OpenSSL options to be used on connections;
450 typically this is to set bug compatibility features which the OpenSSL
451 developers have not enabled by default. There may be security
452 consequences for certain options, so these should not be changed
455 2. A new pipe transport option, "permit_coredumps", may help with problem
456 diagnosis in some scenarios. Note that Exim is typically installed as
457 a setuid binary, which on most OSes will inhibit coredumps by default,
458 so that safety mechanism would have to be overridden for this option to
459 be able to take effect.
461 3. ClamAV 0.95 is now required for ClamAV support in Exim, unless
462 Local/Makefile sets: WITH_OLD_CLAMAV_STREAM=yes
463 Note that this switches Exim to use a new API ("INSTREAM") and a future
464 release of ClamAV will remove support for the old API ("STREAM").
466 The av_scanner option, when set to "clamd", now takes an optional third
467 part, "local", which causes Exim to pass a filename to ClamAV instead of
468 the file content. This is the same behaviour as when clamd is pointed at
469 a Unix-domain socket. For example:
471 av_scanner = clamd:192.0.2.3 1234:local
473 ClamAV's ExtendedDetectionInfo response format is now handled.
475 4. There is now a -bmalware option, restricted to admin users. This option
476 takes one parameter, a filename, and scans that file with Exim's
477 malware-scanning framework. This is intended purely as a debugging aid
478 to ensure that Exim's scanning is working, not to replace other tools.
479 Note that the ACL framework is not invoked, so if av_scanner references
480 ACL variables without a fallback then this will fail.
482 5. There is a new expansion operator, "reverse_ip", which will reverse IP
483 addresses; IPv4 into dotted quad, IPv6 into dotted nibble. Examples:
485 ${reverse_ip:192.0.2.4}
487 ${reverse_ip:2001:0db8:c42:9:1:abcd:192.0.2.3}
488 -> 3.0.2.0.0.0.0.c.d.c.b.a.1.0.0.0.9.0.0.0.2.4.c.0.8.b.d.0.1.0.0.2
490 6. There is a new ACL control called "debug", to enable debug logging.
491 This allows selective logging of certain incoming transactions within
492 production environments, with some care. It takes two options, "tag"
493 and "opts"; "tag" is included in the filename of the log and "opts"
494 is used as per the -d<options> command-line option. Examples, which
495 don't all make sense in all contexts:
498 control = debug/tag=.$sender_host_address
499 control = debug/opts=+expand+acl
500 control = debug/tag=.$message_exim_id/opts=+expand
502 7. It has always been implicit in the design and the documentation that
503 "the Exim user" is not root. src/EDITME said that using root was
504 "very strongly discouraged". This is not enough to keep people from
505 shooting themselves in the foot in days when many don't configure Exim
506 themselves but via package build managers. The security consequences of
507 running various bits of network code are severe if there should be bugs in
508 them. As such, the Exim user may no longer be root. If configured
509 statically, Exim will refuse to build. If configured as ref:user then Exim
510 will exit shortly after start-up. If you must shoot yourself in the foot,
511 then henceforth you will have to maintain your own local patches to strip
514 8. There is a new expansion condition, bool_lax{}. Where bool{} uses the ACL
515 condition logic to determine truth/failure and will fail to expand many
516 strings, bool_lax{} uses the router condition logic, where most strings
518 Note: bool{00} is false, bool_lax{00} is true.
520 9. Routers now support multiple "condition" tests.
522 10. There is now a runtime configuration option "tcp_wrappers_daemon_name".
523 Setting this allows an admin to define which entry in the tcpwrappers
524 config file will be used to control access to the daemon. This option
525 is only available when Exim is built with USE_TCP_WRAPPERS. The
526 default value is set at build time using the TCP_WRAPPERS_DAEMON_NAME
529 11. [POSSIBLE CONFIG BREAKAGE] The default value for system_filter_user is now
530 the Exim run-time user, instead of root.
532 12. [POSSIBLE CONFIG BREAKAGE] ALT_CONFIG_ROOT_ONLY is no longer optional and
533 is forced on. This is mitigated by the new build option
534 TRUSTED_CONFIG_LIST which defines a list of configuration files which
535 are trusted; one per line. If a config file is owned by root and matches
536 a pathname in the list, then it may be invoked by the Exim build-time
537 user without Exim relinquishing root privileges.
539 13. [POSSIBLE CONFIG BREAKAGE] The Exim user is no longer automatically
540 trusted to supply -D<Macro[=Value]> overrides on the command-line. Going
541 forward, we recommend using TRUSTED_CONFIG_LIST with shim configs that
542 include the main config. As a transition mechanism, we are temporarily
543 providing a work-around: the new build option WHITELIST_D_MACROS provides
544 a colon-separated list of macro names which may be overridden by the Exim
545 run-time user. The values of these macros are constrained to the regex
546 ^[A-Za-z0-9_/.-]*$ (which explicitly does allow for empty values).
552 1. TWO SECURITY FIXES: one relating to mail-spools which are globally
553 writable, the other to locking of MBX folders (not mbox).
555 2. MySQL stored procedures are now supported.
557 3. The dkim_domain transport option is now a list, not a single string, and
558 messages will be signed for each element in the list (discarding
561 4. The 4.70 release unexpectedly changed the behaviour of dnsdb TXT lookups
562 in the presence of multiple character strings within the RR. Prior to 4.70,
563 only the first string would be returned. The dnsdb lookup now, by default,
564 preserves the pre-4.70 semantics, but also now takes an extended output
565 separator specification. The separator can be followed by a semicolon, to
566 concatenate the individual text strings together with no join character,
567 or by a comma and a second separator character, in which case the text
568 strings within a TXT record are joined on that second character.
569 Administrators are reminded that DNS provides no ordering guarantees
570 between multiple records in an RRset. For example:
572 foo.example. IN TXT "a" "b" "c"
573 foo.example. IN TXT "d" "e" "f"
575 ${lookup dnsdb{>/ txt=foo.example}} -> "a/d"
576 ${lookup dnsdb{>/; txt=foo.example}} -> "def/abc"
577 ${lookup dnsdb{>/,+ txt=foo.example}} -> "a+b+c/d+e+f"
583 1. Native DKIM support without an external library.
584 (Note that if no action to prevent it is taken, a straight upgrade will
585 result in DKIM verification of all signed incoming emails. See spec
586 for details on conditionally disabling)
588 2. Experimental DCC support via dccifd (contributed by Wolfgang Breyha).
590 3. There is now a bool{} expansion condition which maps certain strings to
591 true/false condition values (most likely of use in conjunction with the
592 and{} expansion operator).
594 4. The $spam_score, $spam_bar and $spam_report variables are now available
597 5. exim -bP now supports "macros", "macro_list" or "macro MACRO_NAME" as
598 options, provided that Exim is invoked by an admin_user.
600 6. There is a new option gnutls_compat_mode, when linked against GnuTLS,
601 which increases compatibility with older clients at the cost of decreased
602 security. Don't set this unless you need to support such clients.
604 7. There is a new expansion operator, ${randint:...} which will produce a
605 "random" number less than the supplied integer. This randomness is
606 not guaranteed to be cryptographically strong, but depending upon how
607 Exim was built may be better than the most naive schemes.
609 8. Exim now explicitly ensures that SHA256 is available when linked against
612 9. The transport_filter_timeout option now applies to SMTP transports too.
618 1. Preliminary DKIM support in Experimental.
624 1. The body_linecount and body_zerocount C variables are now exported in the
627 2. When a dnslists lookup succeeds, the key that was looked up is now placed
628 in $dnslist_matched. When the key is an IP address, it is not reversed in
629 this variable (though it is, of course, in the actual lookup). In simple
632 deny dnslists = spamhaus.example
634 the key is also available in another variable (in this case,
635 $sender_host_address). In more complicated cases, however, this is not
636 true. For example, using a data lookup might generate a dnslists lookup
639 deny dnslists = spamhaus.example/<|192.168.1.2|192.168.6.7|...
641 If this condition succeeds, the value in $dnslist_matched might be
642 192.168.6.7 (for example).
644 3. Authenticators now have a client_condition option. When Exim is running as
645 a client, it skips an authenticator whose client_condition expansion yields
646 "0", "no", or "false". This can be used, for example, to skip plain text
647 authenticators when the connection is not encrypted by a setting such as:
649 client_condition = ${if !eq{$tls_cipher}{}}
651 Note that the 4.67 documentation states that $tls_cipher contains the
652 cipher used for incoming messages. In fact, during SMTP delivery, it
653 contains the cipher used for the delivery. The same is true for
656 4. There is now a -Mvc <message-id> option, which outputs a copy of the
657 message to the standard output, in RFC 2822 format. The option can be used
658 only by an admin user.
660 5. There is now a /noupdate option for the ratelimit ACL condition. It
661 computes the rate and checks the limit as normal, but it does not update
662 the saved data. This means that, in relevant ACLs, it is possible to lookup
663 the existence of a specified (or auto-generated) ratelimit key without
664 incrementing the ratelimit counter for that key.
666 In order for this to be useful, another ACL entry must set the rate
667 for the same key somewhere (otherwise it will always be zero).
672 # Read the rate; if it doesn't exist or is below the maximum
674 deny ratelimit = 100 / 5m / strict / noupdate
675 log_message = RATE: $sender_rate / $sender_rate_period \
676 (max $sender_rate_limit)
678 [... some other logic and tests...]
680 warn ratelimit = 100 / 5m / strict / per_cmd
681 log_message = RATE UPDATE: $sender_rate / $sender_rate_period \
682 (max $sender_rate_limit)
683 condition = ${if le{$sender_rate}{$sender_rate_limit}}
687 6. The variable $max_received_linelength contains the number of bytes in the
688 longest line that was received as part of the message, not counting the
689 line termination character(s).
691 7. Host lists can now include +ignore_defer and +include_defer, analagous to
692 +ignore_unknown and +include_unknown. These options should be used with
693 care, probably only in non-critical host lists such as whitelists.
695 8. There's a new option called queue_only_load_latch, which defaults true.
696 If set false when queue_only_load is greater than zero, Exim re-evaluates
697 the load for each incoming message in an SMTP session. Otherwise, once one
698 message is queued, the remainder are also.
700 9. There is a new ACL, specified by acl_smtp_notquit, which is run in most
701 cases when an SMTP session ends without sending QUIT. However, when Exim
702 itself is is bad trouble, such as being unable to write to its log files,
703 this ACL is not run, because it might try to do things (such as write to
704 log files) that make the situation even worse.
706 Like the QUIT ACL, this new ACL is provided to make it possible to gather
707 statistics. Whatever it returns (accept or deny) is immaterial. The "delay"
708 modifier is forbidden in this ACL.
710 When the NOTQUIT ACL is running, the variable $smtp_notquit_reason is set
711 to a string that indicates the reason for the termination of the SMTP
712 connection. The possible values are:
714 acl-drop Another ACL issued a "drop" command
715 bad-commands Too many unknown or non-mail commands
716 command-timeout Timeout while reading SMTP commands
717 connection-lost The SMTP connection has been lost
718 data-timeout Timeout while reading message data
719 local-scan-error The local_scan() function crashed
720 local-scan-timeout The local_scan() function timed out
721 signal-exit SIGTERM or SIGINT
722 synchronization-error SMTP synchronization error
723 tls-failed TLS failed to start
725 In most cases when an SMTP connection is closed without having received
726 QUIT, Exim sends an SMTP response message before actually closing the
727 connection. With the exception of acl-drop, the default message can be
728 overridden by the "message" modifier in the NOTQUIT ACL. In the case of a
729 "drop" verb in another ACL, it is the message from the other ACL that is
732 10. For MySQL and PostgreSQL lookups, it is now possible to specify a list of
733 servers with individual queries. This is done by starting the query with
734 "servers=x:y:z;", where each item in the list may take one of two forms:
736 (1) If it is just a host name, the appropriate global option (mysql_servers
737 or pgsql_servers) is searched for a host of the same name, and the
738 remaining parameters (database, user, password) are taken from there.
740 (2) If it contains any slashes, it is taken as a complete parameter set.
742 The list of servers is used in exactly the same was as the global list.
743 Once a connection to a server has happened and a query has been
744 successfully executed, processing of the lookup ceases.
746 This feature is intended for use in master/slave situations where updates
747 are occurring, and one wants to update a master rather than a slave. If the
748 masters are in the list for reading, you might have:
750 mysql_servers = slave1/db/name/pw:slave2/db/name/pw:master/db/name/pw
752 In an updating lookup, you could then write
754 ${lookup mysql{servers=master; UPDATE ...}
756 If, on the other hand, the master is not to be used for reading lookups:
758 pgsql_servers = slave1/db/name/pw:slave2/db/name/pw
760 you can still update the master by
762 ${lookup pgsql{servers=master/db/name/pw; UPDATE ...}
764 11. The message_body_newlines option (default FALSE, for backwards
765 compatibility) can be used to control whether newlines are present in
766 $message_body and $message_body_end. If it is FALSE, they are replaced by
773 1. There is a new log selector called smtp_no_mail, which is not included in
774 the default setting. When it is set, a line is written to the main log
775 whenever an accepted SMTP connection terminates without having issued a
778 2. When an item in a dnslists list is followed by = and & and a list of IP
779 addresses, the behaviour was not clear when the lookup returned more than
780 one IP address. This has been solved by the addition of == and =& for "all"
781 rather than the default "any" matching.
783 3. Up till now, the only control over which cipher suites GnuTLS uses has been
784 for the cipher algorithms. New options have been added to allow some of the
785 other parameters to be varied.
787 4. There is a new compile-time option called ENABLE_DISABLE_FSYNC. When it is
788 set, Exim compiles a runtime option called disable_fsync.
790 5. There is a new variable called $smtp_count_at_connection_start.
792 6. There's a new control called no_pipelining.
794 7. There are two new variables called $sending_ip_address and $sending_port.
795 These are set whenever an SMTP connection to another host has been set up.
797 8. The expansion of the helo_data option in the smtp transport now happens
798 after the connection to the server has been made.
800 9. There is a new expansion operator ${rfc2047d: that decodes strings that
801 are encoded as per RFC 2047.
803 10. There is a new log selector called "pid", which causes the current process
804 id to be added to every log line, in square brackets, immediately after the
807 11. Exim has been modified so that it flushes SMTP output before implementing
808 a delay in an ACL. It also flushes the output before performing a callout,
809 as this can take a substantial time. These behaviours can be disabled by
810 obeying control = no_delay_flush or control = no_callout_flush,
811 respectively, at some earlier stage of the connection.
813 12. There are two new expansion conditions that iterate over a list. They are
814 called forany and forall.
816 13. There's a new global option called dsn_from that can be used to vary the
817 contents of From: lines in bounces and other automatically generated
818 messages ("delivery status notifications" - hence the name of the option).
820 14. The smtp transport has a new option called hosts_avoid_pipelining.
822 15. By default, exigrep does case-insensitive matches. There is now a -I option
823 that makes it case-sensitive.
825 16. A number of new features ("addresses", "map", "filter", and "reduce") have
826 been added to string expansions to make it easier to process lists of
827 items, typically addresses.
829 17. There's a new ACL modifier called "continue". It does nothing of itself,
830 and processing of the ACL always continues with the next condition or
831 modifier. It is provided so that the side effects of expanding its argument
834 18. It is now possible to use newline and other control characters (those with
835 values less than 32, plus DEL) as separators in lists.
837 19. The exigrep utility now has a -v option, which inverts the matching
840 20. The host_find_failed option in the manualroute router can now be set to
847 No new features were added to 4.66.
853 No new features were added to 4.65.
859 1. ACL variables can now be given arbitrary names, as long as they start with
860 "acl_c" or "acl_m" (for connection variables and message variables), are at
861 least six characters long, with the sixth character being either a digit or
864 2. There is a new ACL modifier called log_reject_target. It makes it possible
865 to specify which logs are used for messages about ACL rejections.
867 3. There is a new authenticator called "dovecot". This is an interface to the
868 authentication facility of the Dovecot POP/IMAP server, which can support a
869 number of authentication methods.
871 4. The variable $message_headers_raw provides a concatenation of all the
872 messages's headers without any decoding. This is in contrast to
873 $message_headers, which does RFC2047 decoding on the header contents.
875 5. In a DNS black list, if two domain names, comma-separated, are given, the
876 second is used first to do an initial check, making use of any IP value
877 restrictions that are set. If there is a match, the first domain is used,
878 without any IP value restrictions, to get the TXT record.
880 6. All authenticators now have a server_condition option.
882 7. There is a new command-line option called -Mset. It is useful only in
883 conjunction with -be (that is, when testing string expansions). It must be
884 followed by a message id; Exim loads the given message from its spool
885 before doing the expansions.
887 8. Another similar new command-line option is called -bem. It operates like
888 -be except that it must be followed by the name of a file that contains a
891 9. When an address is delayed because of a 4xx response to a RCPT command, it
892 is now the combination of sender and recipient that is delayed in
893 subsequent queue runs until its retry time is reached.
895 10. Unary negation and the bitwise logical operators and, or, xor, not, and
896 shift, have been added to the eval: and eval10: expansion items.
898 11. The variables $interface_address and $interface_port have been renamed
899 as $received_ip_address and $received_port, to make it clear that they
900 relate to message reception rather than delivery. (The old names remain
901 available for compatibility.)
903 12. The "message" modifier can now be used on "accept" and "discard" acl verbs
904 to vary the message that is sent when an SMTP command is accepted.
910 1. There is a new Boolean option called filter_prepend_home for the redirect
913 2. There is a new acl, set by acl_not_smtp_start, which is run right at the
914 start of receiving a non-SMTP message, before any of the message has been
917 3. When an SMTP error message is specified in a "message" modifier in an ACL,
918 or in a :fail: or :defer: message in a redirect router, Exim now checks the
919 start of the message for an SMTP error code.
921 4. There is a new parameter for LDAP lookups called "referrals", which takes
922 one of the settings "follow" (the default) or "nofollow".
924 5. Version 20070721.2 of exipick now included, offering these new options:
926 After all other sorting options have bee processed, reverse order
927 before displaying messages (-R is synonym).
929 Randomize order of matching messages before displaying.
931 Instead of displaying the matching messages, display the sum
933 --sort <variable>[,<variable>...]
934 Before displaying matching messages, sort the messages according to
935 each messages value for each variable.
937 Negate the value for every test (returns inverse output from the
938 same criteria without --not).
944 1. The ${readsocket expansion item now supports Internet domain sockets as well
945 as Unix domain sockets. If the first argument begins "inet:", it must be of
946 the form "inet:host:port". The port is mandatory; it may be a number or the
947 name of a TCP port in /etc/services. The host may be a name, or it may be an
948 IP address. An ip address may optionally be enclosed in square brackets.
949 This is best for IPv6 addresses. For example:
951 ${readsocket{inet:[::1]:1234}{<request data>}...
953 Only a single host name may be given, but if looking it up yield more than
954 one IP address, they are each tried in turn until a connection is made. Once
955 a connection has been made, the behaviour is as for ${readsocket with a Unix
958 2. If a redirect router sets up file or pipe deliveries for more than one
959 incoming address, and the relevant transport has batch_max set greater than
960 one, a batch delivery now occurs.
962 3. The appendfile transport has a new option called maildirfolder_create_regex.
963 Its value is a regular expression. For a maildir delivery, this is matched
964 against the maildir directory; if it matches, Exim ensures that a
965 maildirfolder file is created alongside the new, cur, and tmp directories.
971 The documentation is up-to-date for the 4.61 release. Major new features since
972 the 4.60 release are:
974 . An option called disable_ipv6, to disable the use of IPv6 completely.
976 . An increase in the number of ACL variables to 20 of each type.
978 . A change to use $auth1, $auth2, and $auth3 in authenticators instead of $1,
979 $2, $3, (though those are still set) because the numeric variables get used
980 for other things in complicated expansions.
982 . The default for rfc1413_query_timeout has been changed from 30s to 5s.
984 . It is possible to use setclassresources() on some BSD OS to control the
985 resources used in pipe deliveries.
987 . A new ACL modifier called add_header, which can be used with any verb.
989 . More errors are detectable in retry rules.
991 There are a number of other additions too.
997 The documentation is up-to-date for the 4.60 release. Major new features since
998 the 4.50 release are:
1000 . Support for SQLite.
1002 . Support for IGNOREQUOTA in LMTP.
1004 . Extensions to the "submission mode" features.
1006 . Support for Client SMTP Authorization (CSA).
1008 . Support for ratelimiting hosts and users.
1010 . New expansion items to help with the BATV "prvs" scheme.
1012 . A "match_ip" condition, that matches an IP address against a list.
1014 There are many more minor changes.
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