I am using Postfix-CourierImap-Squirrelmail on my Kubuntu distro and have a working mail server. I would like to forward all mail coming to my mail server into a program and send it back to the sender. How do I do this? I read that one can do it in the .forward file in the home directory, but I am unable to find that anywhere. Please guide me as to where in the configuration I should change, so that, this is possible.

Thanks in advance