3.2. Forwarding
 
MTA aliases usually require administrator privileges to set up. But it is desirable for mail users to be able to set up forwarding of their own mail without administrator intervention.
 
To support this, most MTAs follow sendmail's lead and look for a file called .forward in your home directory. The contents of this file is interpreted like the target of an alias which should receive all your mail. The most common use for this facility is to redirect your mail to an account on another machine.