EXIM ALIAS AND LOCAL DOMAIN CONFIGURATION


This module implements handling of e-mail aliases and configuring
domains for which e-mail should be accepted locally for the exim MTA
(http://www.exim.org).

A .aliases file in a domain's directory controls its e-mail
aliases. A target below may one of three things:

 * a local username, to deliver mail to that user
 * an e-mail address, to forward mail to it
 * !, to delete mail to this address

The file then consists of a sequence of lines of the following types. 

 * user target: Send all mail to user@domain to target
 * * target: Send all mail to domain not matching any other rule
to target. However, if mail is sent to an existing UNIX username on
Abulafia, the message will go to that account
 * ** target: Send all mail that does not match another rule to
domain to target, even mail addressed to real UNIX usernames

These policies are implemented by writing to two different alias files
which are meant to be processed in different passes. The first one
(probably /etc/aliases) should be check before exim checks an e-mail
recipient against local useranmes or other special targets. After
this, local usernames should be checked. Finally, the second alias
file (such as /etc/aliases.default) should be checked, to implement
"catch-all" addresses that handle all mail not matching other rules.


The module also handles receiving notifications of which domains
delegate mail handling to this host and incorporating this information
into exim configuration files. A file local_domains is maintained in
the domtool scratchDir, along with the last version of it in
local_domains.last, to detect when changes have been made. The module
will attempt to generate exim.conf by concatenatning local_domains and
a file exim.base. The paths for these files are configurable in
config.sml, as is the command used to tell exim to reload exim.conf
afterwards.