You can create a .forward.hostname file to redirect mail that is sent to a specific host. For example, if a user's alias has changed from firstname.lastname@example.org to email@example.com, place a .forward.phoenix file in the home directory for sandy.
% cat .forward.phoenix firstname.lastname@example.org "|/usr/bin/vacation sandy" % cat .vacation.msg From: email@example.com (via the vacation program) Subject: my alias has changed My alias has changed to firstname.lastname@example.org. Please use this alias in the future. The mail that I just received from you has been forwarded to my new address. Sandy
In this example, mail can be forwarded to the correct place while the sender is notified of the alias change. Because the vacation program permits only one message file, you can forward only one message at a time. However, if the message is not host specific, one vacation message file can be used by .forward files for many hosts.