-PH/01 There is a new global option called disable_ipv6, which does exactly what
- its name implies. If set true, even if the Exim binary has IPv6 support,
- no IPv6 activities take place. AAAA records are never looked up for host
- names given in manual routing data or elsewhere. AAAA records that are
- received from the DNS as additional data for MX records are ignored. Any
- IPv6 addresses that are listed in local_interfaces, manualroute route
- data, etc. are also ignored. If IP literals are enabled, the ipliteral
- router declines to handle IPv6 literal addresses.
-
-PH/02 There are now 20 of each type of ACL variable by default (instead of 10).
- It is also possible to change the numbers by setting ACL_CVARS and/or
- ACL_MVARS in Local/Makefile. Backward compatibility is maintained if you
- upgrade to this release with existing messages containing ACL variable
- settings on the queue. However, going in the other direction
- (downgrading) will not be compatible; the values of ACL variables will be
- lost.
-
-PH/03 If quota_warn_message contains a From: header, Exim now refrains from
- adding the default one. Similarly, if it contains a Reply-To: header, the
- errors_reply_to option, if set, is not used.
-
-PH/04 The variables $auth1, $auth2, $auth3 are now available in authenticators,
- containing the same values as $1, $2, $3. The new variables are provided
- because the numerical variables can be reset during string expansions
- (for example, during a "match" operation) and so may lose the
- authentication data. The preferred variables are now the new ones, with
- the use of the numerical ones being deprecated, though the support will
- not be removed, at least, not for a long time.
-
-PH/05 The "control=freeze" ACL modifier can now be followed by /no_tell. If
- the global option freeze_tell is set, it is ignored for the current
- message (that is, nobody is told about the freezing), provided all the
- "control=freeze" modifiers that are obeyed in the current message have
- the /no_tell option.
-
-PH/06 In both GnuTLS and OpenSSL, an expansion of tls_privatekey that results
- in an empty string is now treated as unset.
-
-PH/07 There is a new log selector called sender_verify_fail, which is set by
- default. If it is unset, the separate log line that gives details of a
- sender verification failure is not written. Log lines for the rejection
- of SMTP commands (e.g. RCPT) contain just "sender verify failed", so some
- detail is lost.
-
-PH/08 The default for dns_check_names_pattern now allows slashes within names,
- as there are now some PTR records that contain slashes. This check is
- only to protect against broken name servers that fall over on strange
- characters, so the fact that it applies to all lookups doesn't matter.
-
-PH/09 The default for rfc4131_query_timeout has been changed from 30s to 5s.
-
-PH/10 When compiled on FreeBSD, NetBSD, or BSD/OS, the pipe transport has a new
- Boolean option called use_classresources, defaulting false. If it is set
- true, the setclassresources() function is used to set resource limits
- when a pipe transport is run to perform a delivery. The limits for the
- uid under which the pipe is to run are obtained from the login class
- database.
-
-PH/11 If retry_interval_max is set greater than 24 hours, it is quietly reset
- to 24 hours. This avoids potential overflow problems when processing G
- and H retry rules, and it seems reasonable to require a retry at least
- once a day.
-
-PH/12 When the plaintext authenticator is running as a client, the server
- challenges are now checked to ensure they are valid base64 strings. The
- default action on failure is to abort the authentication. However, if
- client_ignore_invalid_base64 is set true, invalid responses are ignored.
-
-PH/13 When the plaintext authenticator is running as a client, the challenges
- from the server are placed in $auth1, $auth2, etc. as they are received.
- Thus, the challege that is received in response to sending the first
- string (with the AUTH command) can be used in the expansion of the second
- string, and so on. Currently, up to 3 challenge strings are available in
- this way. If an invalid base64 string is received when client_ignore_
- invalid_base64 is set, an empty string is put in the $auth<n> variable.
-
-PH/14 Messages created by the autoreply transport now contain a References:
- header. This is constructed in accordance with rules that are described
- in section 3.64 of RFC 2822, which states that replies should contain
- such a header line, and section 3.14 of RFC 3834, which states that
- automatic responses are not different in this respect. However, because
- some mail processing software does not cope well with very long header
- lines, no more than 12 message IDs are copied from the References: header
- line in the incoming message. If there are more than 12, the first one
- and then the final 11 are copied, before adding the message ID of the
- incoming message.
-
-PH/15 The smtp transport has a new option called authenticated_sender_force.
- When set true, it allows the authenticated_sender option's value to be
- used, even if Exim has not authenticated as a client.
-
-PH/16 The expansion ${time_eval:<string>} converts an Exim time string such as
- 2d4h1m into a number of seconds.
-
-PH/17 The ACL modifier control=allow_auth_unadvertised can be used to permit a
- client host to use the SMTP AUTH command even when it has not been
- advertised in response to EHLO. Furthermore, because there are apparently
- some really broken clients that do this, Exim will even accept AUTH after
- HELO when this control is set. It should only be used if you really need
- it, and you should limit its use to those broken hosts that do not work
- without it. For example:
-
- warn hosts = 192.168.34.25
- control = allow_auth_unadvertised
-
- This control is permitted only in the connection and HELO ACLs.
-
-PH/18 There is a new ACL modifier called "add_header" which does what its name
- implies. It specifies one of more header lines that are to be added to an
- incoming message, assuming, of course, that the message is ultimately
- accepted.
-
- This modifier is permitted in the MAIL, RCPT, PREDATA, DATA, MIME, and
- non-SMTP ACLs (in other words, those that are concerned with accepting a
- message). Added header lines are accumulated during the MAIL, RCPT, and
- PREDATA ACLs, with any duplicates being discarded. They are then added to
- the message before processing the DATA and MIME ACLs, during which
- further added header lines are accumulated, again with duplicates
- discarded. Thus, it is possible to add two identical header lines to an
- SMTP message, but only if one is added before DATA and one after.
-
- In the case of non-SMTP messages, new headers are accumulated during the
- non-SMTP ACL, and added to the message at the end.
-
- The add_header modifier is available for use with all ACL verbs. In the
- case of the WARN verb, add_header supersedes the use of "message" for
- this purpose; for the other verbs, it provides a new facility. If both
- add_header and "message" are present on a WARN verb, both are processed
- according to their specifications.
-
- The add_header modifier acts immediately it is encountered during the
- processing of an ACL. This is different to the (now-deprecated) use of
- "message" on a WARN verb, where the action is taken only if all the
- conditions are true. Notice the difference between these two cases on a
- RCPT ACL:
-
- deny add_header = ADDED: some text
- <some condition>
-
- deny <some condition>
- add_header = ADDED: some text
-
- In the first case, the header is always added, whether or not the current
- recipient is rejected. In the second case, the header is added only if
- the recipient is rejected.
-
- If add_header appears more than once on an ACL statement, multiple
- headers are added, provided that they have different content. (In the
- case of WARN with "message", only the last value of "message" is used.)
-
- The facility for specifying where the new header is to be inserted, as
- described for WARN with "message" in section 39.19 of the 4.60 manual, is
- supported.
-
-PH/19 The following errors can now be detected in retry rules:
-
- mail_4xx This is like rcpt_4xx, but applies to MAIL commands
-
- data_4xx This is like rcpt_4xx, but applies to DATA commands and the
- response code after the end of the data
-
- lost_connection This error occurs when the server unexpectedly closes
- the SMTP connection. There may, of course, legitmate reasons
- for this (host died, network died), but if it repeats a lot
- for the same host, it indicates something odd.
-
- tls_required The server was required to use TLS (hosts_require_tls),
- but either did not offer it, or responded with 4xx to
- STARTTLS, or there was a problem setting up the TLS connection
-
- Note that a 5xx response to STARTTLS is a permanent error.