Setup email forwarding in linux/unix

Email forwarding can be setup in an email client such as Thunderbird.

Under linux/unix, it can done by admin or by user himself, as explained here.

To do it by the user himself, he only needs to create a file .forward in his account root, and enter the forward email addresses separated by comma or new line. The .forward file should have permission 644.

An example .forward file is:

"|/usr/local/bin/procmail"
example@gmail.com