Alias File

The alias file is used to set aliases not set in the directory. In particular, the postmaster alias is a good example. The MTA has to be restarted for any changes to take effect. Any line that begins with an exclamation point is considered to be a comment and is ignored. Blank lines are also ignored.

A physical line in this file is limited to 1024 characters. You can split a logical line into multiple physical lines using the backslash (\) continuation character.

The format of the file is as follows:

user@domain: <address>

user@domain: <address> <address> ...

The following is an example aliases file:

! A /var/mail user
mailsrv@siroe.com: mailsrv@native-daemon

!A message store user
ms_testuser@siroe.com: mstestuser@ims-ms-daemon

Including Other Files in the Alias File

Other files can be included in the primary alias file. A line of the following form directs the MTA to read the file-spec file:

<file-spec

The file specification must be a complete file path specification and the file must have the same protections as the primary alias file; for example, it must be world readable.

The contents of the included file are inserted into the alias file at its point of reference. The same effect can be achieved by replacing the reference to the included file with the file’s actual contents. The format of include files is identical to that of the primary alias file itself. Indeed, include files may themselves include other files. Up to three levels of include file nesting are allowed.