-$Cambridge: exim/doc/doc-txt/NewStuff,v 1.108 2006/07/31 14:19:31 ph10 Exp $
+$Cambridge: exim/doc/doc-txt/NewStuff,v 1.120 2006/11/06 15:50:12 ph10 Exp $
New Features in Exim
--------------------
-This file contains descriptions of new features that have been added to Exim,
-but have not yet made it into the main manual (which is most conveniently
-updated when there is a relatively large batch of changes). The doc/ChangeLog
-file contains a listing of all changes, including bug fixes.
+This file contains descriptions of new features that have been added to Exim.
+Before a formal release, there may be quite a lot of detail so that people can
+test from the snapshots or the CVS before the documentation is updated. Once
+the documentation is updated, this file is reduced to a short list.
+
+
+Version 4.64
+------------
+
+1. ACL variables can now be given arbitrary names, as long as they start with
+ "acl_c" or "acl_m" (for connection variables and message variables), are
+ at least six characters long, with the sixth character being either a digit
+ or an underscore. The rest of the name can contain alphanumeric characters
+ and underscores. This is a compatible change because the old set of
+ variables such as acl_m12 are a subset of the allowed names. There may now
+ be any number of ACL variables. For example:
+
+ set acl_c13 = value for original ACL variable
+ set acl_c13b = whatever
+ set acl_m_foo = something
+
+ What happens if a syntactically valid but undefined ACL variable is
+ referenced depends on the setting of the strict_acl_vars option. If it is
+ false (the default), an empty string is substituted; if it is true, an error
+ is generated. This affects all ACL variables, including the "old" ones such
+ as acl_c4. (Previously there wasn't the concept of an undefined ACL
+ variable.)
+
+ The implementation has been done in such a way that spool files containing
+ ACL variable settings written by previous releases of Exim are compatible
+ and can be read by the new release. If only the original numeric names are
+ used, spool files written by the new release can be read by earlier
+ releases.
+
+2. There is a new ACL modifier called log_reject_target. It makes it possible
+ to specify which logs are used for messages about ACL rejections. Its
+ argument is a list of words which can be "main", "reject", or "panic". The
+ default is "main:reject". The list may be empty, in which case a rejection
+ is not logged at all. For example, this ACL fragment writes no logging
+ information when access is denied:
+
+ deny <some conditions>
+ log_reject_target =
+
+ The modifier can be used in SMTP and non-SMTP ACLs. It applies to both
+ permanent and temporary rejections.
+
+3. There is a new authenticator called "dovecot". This is an interface to the
+ authentication facility of the Dovecot POP/IMAP server, which can support a
+ number of authentication methods. If you are using Dovecot to authenticate
+ POP/IMAP clients, it might be helpful to use the same mechanisms for SMTP
+ authentication. This is a server authenticator only. The only option is
+ server_socket, which must specify the socket which is the interface to
+ Dovecot authentication. The public_name option must specify an
+ authentication mechanism that Dovecot is configured to support. You can have
+ several authenticators for different mechanisms. For example:
+
+ dovecot_plain:
+ driver = dovecot
+ public_name = PLAIN
+ server_name = /var/run/dovecot/auth-client
+ server_setid = $auth1
+
+ dovecot_ntlm:
+ driver = dovecot
+ public_name = NTLM
+ server_name = /var/run/dovecot/auth-client
+ server_setid = $auth1
+
+ If the SMTP connection is encrypted, or if $sender_host_address is equal to
+ $interface_address (that is, the connection is local), the "secured" option
+ is passed in the Dovecot authentication command. If, for a TLS connection, a
+ client certificate has been verified, the "valid-client-cert" option is
+ passed.
+
+4. The variable $message_headers_raw provides a concatenation of all the
+ messages's headers without any decoding. This is in contrast to
+ $message_headers, which does RFC2047 decoding on the header contents.
+
+5. In a DNS black list, when the facility for restricting the matching IP
+ values is used, the text from the TXT record that is set in $dnslist_text
+ may not reflect the true reason for rejection. This happens when lists are
+ merged and the IP address in the A record is used to distinguish them;
+ unfortunately there is only one TXT record. One way round this is not to use
+ merged lists, but that can be inefficient because it requires multiple DNS
+ lookups where one would do in the vast majority of cases when the host of
+ interest is not on any of the lists.
+
+ A less inefficient way of solving this problem has now been implemented. If
+ two domain names, comma-separated, are given, the second is used first to do
+ an initial check, making use of any IP value restrictions that are set. If
+ there is a match, the first domain is used, without any IP value
+ restrictions, to get the TXT record. As a byproduct of this, there is also a
+ check that the IP being tested is indeed on the first list. The first domain
+ is the one that is put in $dnslist_domain. For example:
+
+ reject message = rejected because $sender_ip_address is blacklisted \
+ at $dnslist_domain\n$dnslist_text
+ dnslists = sbl.spamhaus.org,sbl-xbl.spamhaus.org=127.0.0.2 : \
+ dul.dnsbl.sorbs.net,dnsbl.sorbs.net=127.0.0.10
+
+ For the first blacklist item, this starts by doing a lookup in
+ sbl-xbl.spamhaus.org and testing for a 127.0.0.2 return. If there is a
+ match, it then looks in sbl.spamhaus.org, without checking the return value,
+ and as long as something is found, it looks for the corresponding TXT
+ record. If there is no match in sbl-xbl.spamhaus.org, nothing more is done.
+ The second blacklist item is processed similarly.
+
+ If you are interested in more than one merged list, the same list must be
+ given several times, but because the results of the DNS lookups are cached,
+ the DNS calls themselves are not repeated. For example:
+
+ reject dnslists = http.dnsbl.sorbs.net,dnsbl.sorbs.net=127.0.0.2 : \
+ socks.dnsbl.sorbs.net,dnsbl.sorbs.net=127.0.0.3 : \
+ misc.dnsbl.sorbs.net,dnsbl.sorbs.net=127.0.0.4 : \
+ dul.dnsbl.sorbs.net,dnsbl.sorbs.net=127.0.0.10
+
+ In this case there is a lookup in dnsbl.sorbs.net, and if none of the IP
+ values matches (or if no record is found), this is the only lookup that is
+ done. Only if there is a match is one of the more specific lists consulted.
+
+6. All authenticators now have a server_condition option. Previously, only
+ plaintext had this, and this has not changed: it must be set to the
+ authenticator as a server. For the others, if server_condition is set, it is
+ expanded if authentication is successful, and treated exactly as it is in
+ plaintext. This can serve as a means of adding authorization to an
+ authenticator.
+
+7. There is a new command-line option called -Mset. It is useful only in
+ conjunction with -be (that is, when testing string expansions). It must be
+ followed by a message id; Exim loads the given message from its spool before
+ doing the expansions, thus setting message-specific variables such as
+ $message_size and the header variables. The $recipients variable is
+ available. This feature is provided to make it easier to test expansions
+ that make use of these variables. However, Exim must be called by an admin
+ user when -Mset is used.
+
+8. Another similar new command-line option is called -bem. It operates like -be
+ except that it must be followed by the name of a file. For example:
+
+ exim -bem /tmp/testmessage
+
+ The file is read as a message (as if receiving a locally-submitted non-SMTP
+ message) before any of the test expansions are done. Thus, message-specific
+ variables such as $message_size and $h_from: are available. However, no
+ Received: header is added to the message. If the -t option is set,
+ recipients are read from the headers in the normal way, and are shown in the
+ $recipients variable. Note that recipients cannot be given on the command
+ line, because further arguments are taken as strings to expand (just like
+ -be).
+
+9. When an address is delayed because of a 4xx response to a RCPT command, it
+ is now the combination of sender and recipient that is delayed in subsequent
+ queue runs until its retry time is reached. You can revert to the previous
+ behavious, that is, delay the recipient independent of the sender, by
+ setting address_retry_include_sender=false in the smtp transport. However,
+ this can lead to problems with servers that regularly issue 4xx responses to
+ RCPT commands.
+
+
Version 4.63
------------
1. There is a new Boolean option called filter_prepend_home for the redirect
- router. It defaults true, for backward compatibility. If a "save" command in
- an Exim filter has a relative path for its argument, and $home is defined,
- it is automatically prepended to the relative path. This action can now be
- prevented by setting filter_prepend_home false.
+ router.
2. There is a new acl, set by acl_not_smtp_start, which is run right at the
start of receiving a non-SMTP message, before any of the message has been
- read. (This is the analogue of the acl_smtp_predata ACL for SMTP input.) The
- result of this ACL is ignored; it cannot be used to reject a message. If
- you really need to, you could set a value in an ACL variable here and reject
- based on that in the acl_not_smtp ACL. However, this ACL can be used to set
- controls, and in particular, it can be used to set control=suppress_local_
- fixups, which cannot be used in the acl_not_smtp ACL because by the time
- that ACL is run, it is too late. When the acl_not_smtp_start ACL is run, the
- sender and recipients are known, so the "senders" and "sender_domains"
- conditions and $sender_address and $recipients variables can be used.
- Variables such as $authenticated_ sender are also available. It is possible
- to specify added header lines in this ACL.
+ read.
3. When an SMTP error message is specified in a "message" modifier in an ACL,
or in a :fail: or :defer: message in a redirect router, Exim now checks the
- start of the message for an SMTP error code. This consists of three digits
- followed by a space, optionally followed by an extended code of the form
- n.n.n, also followed by a space. If this is the case and the very first
- digit is the same as the default error code, the code from the message is
- used instead. If the very first digit is incorrect, a panic error is logged,
- and the default code is used. This is an incompatible change, but it is not
- expected to affect many (if any) configurations. It is possible to suppress
- the use of the supplied code in a redirect router by setting the
- forbid_smtp_code option true. In this case, any SMTP code is quietly
- ignored.
+ start of the message for an SMTP error code.
4. There is a new parameter for LDAP lookups called "referrals", which takes
- one of the settings "follow" (the default) or "nofollow". The latter stops
- the LDAP library from trying to follow referrals issued by the LDAP server.
+ one of the settings "follow" (the default) or "nofollow".
5. Version 20070721.2 of exipick now included, offering these new options:
--reverse
git://git.exim.org / users / jgh / exim.git / blobdiff