could some explain to /etc/aliases

[Don]

On Wed, 2003-12-31 at 12:13, technical wrote:
> what is being forwared to what? what are rules?
> 
> mailer-daemon:  postmaster
> postmaster:     root

The left name is an alias for the name on the right.
The names are resolved until there are no ambiguities.

There's a limit to the number of "redirections" or "depth" of aliases...
I think the limit is 10.

Effectively the above shows mailer-daemon is an alias for "root".
This is determined by any thing sent to mailer-daemon will be sent to
"postmaster".... anything sent to postmaster (including stuff sent to
mailer-daemon) will be sent to "root".

So, with only these two aliases, all mail sent to "mailer-daemon",
"postmaster" and "root" will be delivered to "root".

Nice thing is you can add a new alias so mail directed to root is
directed to a non-privileged user. Just add "root: <username>" to the
aliases file.