-$Cambridge: exim/doc/doc-txt/NewStuff,v 1.7 2004/11/05 16:53:28 ph10 Exp $
+$Cambridge: exim/doc/doc-txt/NewStuff,v 1.25 2005/01/04 16:36:27 ph10 Exp $
New Features in Exim
--------------------
file contains a listing of all changes, including bug fixes.
-Version 4.44
+Version 4.50
------------
1. There is a new build-time option called CONFIGURE_GROUP which works like
CONFIGURE_OWNER. It specifies one additional group that is permitted for
the runtime configuration file when the group write permission is set.
- 2. The "control=submission" facility has a new option /retain_sender. This
+ 2. The "control=submission" facility has a new option /sender_retain. This
has the effect of setting local_sender_retain true and local_from_check
false for the incoming message in which it is encountered.
The main use of these variables is expected to be to distinguish between
rejections of MAIL and rejections of RCPT.
+ 8. The command line option -dd behaves exactly like -d except when used on a
+ command that starts a daemon process. In that case, debugging is turned off
+ for the subprocesses that the daemon creates. Thus, it is useful for
+ monitoring the behaviour of the daemon without creating as much output as
+ full debugging.
+
+ 9. $host_address is now set to the target address during the checking of
+ ignore_target_hosts.
+
+10. There are four new variables called $spool_space, $log_space,
+ $spool_inodes, and $log_inodes. The first two contain the amount of free
+ space in the disk partitions where Exim has its spool directory and log
+ directory, respectively. (When these are in the same partition, the values
+ will, of course, be the same.) The second two variables contain the numbers
+ of free inodes in the respective partitions.
+
+ NOTE: Because disks can nowadays be very large, the values in the space
+ variables are in kilobytes rather than in bytes. Thus, for example, to
+ check in an ACL that there is at least 50M free on the spool, you would
+ write:
+
+ condition = ${if > {$spool_space}{50000}{yes}{no}}
+
+ The values are recalculated whenever any of these variables is referenced.
+ If the relevant file system does not have the concept of inodes, the value
+ of those variables is -1. If the operating system does not have the ability
+ to find the amount of free space (only true for experimental systems), the
+ space value is -1.
+
+11. It is now permitted to omit both strings after an "if" condition; if the
+ condition is true, the result is the string "true". As before, when the
+ second string is omitted, a false condition yields an empty string. This
+ makes it less cumbersome to write custom ACL and router conditions. For
+ example, instead of
+
+ condition = ${if eq {$acl_m4}{1}{yes}{no}}
+
+ or the shorter form
+
+ condition = ${if eq {$acl_m4}{1}{yes}}
+
+ (because the second string has always defaulted to ""), you can now write
+
+ condition = ${if eq {$acl_m4}{1}}
+
+ Previously this was a syntax error.
+
+12. There is a new "record type" that can be specified in dnsdb lookups. It
+ is "zns" (for "zone NS"). It performs a lookup for NS records on the given
+ domain, but if none are found, it removes the first component of the domain
+ name, and tries again. This process continues until NS records are found
+ or there are no more components left (or there's a DNS error). In other
+ words, it may return the name servers for a top-level domain, but it never
+ returns the root name servers. If there are no NS records for the top-level
+ domain, the lookup fails.
+
+ For example, ${lookup dnsdb{zns=xxx.quercite.com}} returns the name
+ servers for quercite.com, whereas ${lookup dnsdb{zns=xxx.edu}} returns
+ the name servers for edu, assuming in each case that there are no NS
+ records for the full domain name.
+
+ You should be careful about how you use this lookup because, unless the
+ top-level domain does not exist, the lookup will always return some host
+ names. The sort of use to which this might be put is for seeing if the name
+ servers for a given domain are on a blacklist. You can probably assume that
+ the name servers for the high-level domains such as .com or .co.uk are not
+ going to be on such a list.
+
+13. Another new "record type" is "mxh"; this looks up MX records just as "mx"
+ does, but it returns only the names of the hosts, omitting the priority
+ values.
+
+14. It is now possible to specify a list of domains or IP addresses to be
+ looked up in a dnsdb lookup. The list is specified in the normal Exim way,
+ with colon as the default separator, but with the ability to change this.
+ For example:
+
+ ${lookup dnsdb{one.domain.com:two.domain.com}}
+ ${lookup dnsdb{a=one.host.com:two.host.com}}
+ ${lookup dnsdb{ptr = <; 1.2.3.4 ; 4.5.6.8}}
+
+ In order to retain backwards compatibility, there is one special case: if
+ the lookup type is PTR and no change of separator is specified, Exim looks
+ to see if the rest of the string is precisely one IPv6 address. In this
+ case, it does not treat it as a list.
+
+ The data from each lookup is concatenated, with newline separators (by
+ default - see 14 below), in the same way that multiple DNS records for a
+ single item are handled.
+
+ The dnsdb lookup fails only if all the DNS lookups fail. If there is a
+ temporary DNS error for any of them, the behaviour is controlled by
+ an optional keyword followed by a comma that may appear before the record
+ type. The possible keywords are "defer_strict", "defer_never", and
+ "defer_lax". With "strict" behaviour, any temporary DNS error causes the
+ whole lookup to defer. With "never" behaviour, a temporary DNS error is
+ ignored, and the behaviour is as if the DNS lookup failed to find anything.
+ With "lax" behaviour, all the queries are attempted, but a temporary DNS
+ error causes the whole lookup to defer only if none of the other lookups
+ succeed. The default is "lax", so the following lookups are equivalent:
+
+ ${lookup dnsdb{defer_lax,a=one.host.com:two.host.com}}
+ ${lookup dnsdb{a=one.host.com:two.host.com}}
+
+ Thus, in the default case, as long as at least one of the DNS lookups
+ yields some data, the dnsdb lookup succeeds.
+
+15. It is now possible to specify the character to be used as a separator when
+ a dnsdb lookup returns data from more than one DNS record. The default is a
+ newline. To specify a different character, put '>' followed by the new
+ character at the start of the query. For example:
+
+ ${lookup dnsdb{>: a=h1.test.ex:h2.test.ex}}
+ ${lookup dnsdb{>| mxh=<;m1.test.ex;m2.test.ex}}
+
+ It is permitted to specify a space as the separator character. Note that
+ more than one DNS record can be found for a single lookup item; this
+ feature is relevant even when you do not specify a list.
+
+ The same effect could be achieved by wrapping the lookup in ${tr...}; this
+ feature is just a syntactic simplification.
+
+16. It is now possible to supply a list of domains and/or IP addresses to be
+ lookup up in a DNS blacklist. Previously, only a single domain name could
+ be given, for example:
+
+ dnslists = black.list.tld/$sender_host_name
+
+ What follows the slash can now be a list. As with all lists, the default
+ separator is a colon. However, because this is a sublist within the list of
+ DNS blacklist domains, it is necessary either to double the separators like
+ this:
+
+ dnslists = black.list.tld/name.1::name.2
+
+ or to change the separator character, like this:
+
+ dnslists = black.list.tld/<;name.1;name.2
+
+ If an item in the list is an IP address, it is inverted before the DNS
+ blacklist domain is appended. If it is not an IP address, no inversion
+ occurs. Consider this condition:
+
+ dnslists = black.list.tls/<;192.168.1.2;a.domain
+
+ The DNS lookups that occur are for
+
+ 2.1.168.192.black.list.tld and a.domain.black.list.tld
+
+ Once a DNS record has been found (that matches a specific IP return
+ address, if specified), no further lookups are done. If there is a
+ temporary DNS error, the rest of the sublist of domains or IP addresses is
+ tried. The dnslists item itself defers only if none of the other DNS
+ lookups in this sublist succeeds. In other words, a successful lookup for
+ any of the items in the sublist overrides a defer for a previous item.
+
+17. The log selector queue_time_overall causes Exim to output the time spent on
+ the queue as an addition to the "Completed" message. Like queue_time (which
+ puts the queue time on individual delivery lines), the time is tagged with
+ "QT=", and it is measured from the time that the message starts to be
+ received, so it includes the reception time.
+
+18. It is now possible to use both -bF and -bf on the same command, in order to
+ test a system filter and a user filter in the same run. For example:
+
+ exim -bF /system/filter -bf /user/filter </test/message
+
+ This is helpful when the system filter adds header lines or sets filter
+ variables that are used by the user filter.
+
+19. The Exiscan patch is now merged into the main source. See src/EDITME for
+ parameters for the build.
+
+20. If the key for a dnsdb PTR lookup is not an IP address, it is used
+ verbatim, without component reversal and without the addition of
+ in-addr.arpa or ip6.arpa.
+
+21. Two changes related to the smtp_active_hostname option:
+
+ (1) $smtp_active_hostname is now available as a variable. Its value
+ sticks with the message and is therefore available in routers and
+ transports at delivery time.
+
+ (2) The default for smtp_banner uses $smtp_active_hostname instead
+ of $primary_hostname.
+
+22. The hosts_max_try_hardlimit option (default 50) is added to the smtp
+ transport. Exim will never try more than this number of IP addresses; if it
+ hits this limit and they are all timed out, the message is bounced, even
+ though not all IP addresses may have been tried. Compare hosts_max_try,
+ which is a "soft" limit, because Exim will exceed it when hosts time out.
+ The new limit is a protection against lunatic DNS configurations with
+ hundreds of IP addresses.
Version 4.43
git://git.exim.org / exim.git / blobdiff