On Wed, 2003-12-31 at 15:13, technical wrote:
what is being forwared to what? what are rules?
mailer-daemon: postmaster
postmaster: root
Basically, an entry on the left hand side gets replaced by the entry (or
entries) on the right hand side.
In the example above, a message addressed to 'mailer-daemon' gets
replaced by 'postmaster' which, in turn, gets replaced by 'root'.
man aliases for more details.