How do I setup my account to forward mail to another location, but keep a copy of the message here too?

Mail forwarding is handled by the file .forward in your home directory. To start forwarding your mail, create this file, using any text editor and insert entries according to the following examples.

Assume your username at the IAS is ezeno, then to forward to your account elea@uom.gr and keep a local copy, you would use:

\ezeno, elea@uom.gr

The backslash() is used to "escape" the name that follows. This tells the mail program to deliver the message locally.
To forward your mail to the local account plato and still keep a copy for ezeno, you would use:

\ezeno, plato

To forward only to elea@uom.gr you would use:

elea@uom.gr

Dynamic Forwarding
A .forward file may also be used to send your mail an application for further processing.
This is the case with the vacation program that notifies senders when you are away from your email.

procmail also works in a similar way, forwarding your mail to the procmail program for processing.
Procmail may be used to file and filter your mail according to several search criteria.