-$Cambridge: exim/doc/doc-txt/NewStuff,v 1.4 2004/10/21 15:24:42 ph10 Exp $
+$Cambridge: exim/doc/doc-txt/NewStuff,v 1.12 2004/11/19 09:45:54 ph10 Exp $
New Features in Exim
--------------------
of the current ACL statement. If you want to preserve it, you can use one
of the ACL variables.
+ 5. The redirect router has two new options: forbid_sieve_filter and
+ forbid_exim_filter. When filtering is enabled by allow_filter, these
+ options control which type(s) of filtering are permitted. By default, both
+ Exim and Sieve filters are allowed.
+
+ 6. A new option for callouts makes it possible to set a different (usually
+ smaller) timeout for making the SMTP connection. The keyword is "connect".
+ For example:
+
+ verify = sender/callout=5s,connect=1s
+
+ If not specified, it defaults to the general timeout value.
+
+ 7. The new variables $sender_verify_failure and $recipient_verify_failure
+ contain information about exactly what failed. In an ACL, after one of
+ these failures, the relevant variable contains one of the following words:
+
+ qualify the address was unqualified (no domain), and the message
+ was neither local nor came from an exempted host;
+
+ route routing failed;
+
+ mail routing succeeded, and a callout was attempted; rejection
+ occurred at or before the MAIL command (that is, on initial
+ connection, HELO, or MAIL);
+
+ recipient the RCPT command in a callout was rejected;
+
+ postmaster the postmaster check in a callout was rejected.
+
+ 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 now 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.
+
Version 4.43
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