In the left pane of the Preferences window, click on "Mail & Newsgroups" to reveal the options for that category. (If you don't have a "Mail & Newsgroups" you may not have the full version of Communicator.)

Click on "Identity", then enter your name and your email address. You may leave the reply-to address and organization blank.

Click on "Mail Servers". Double-click on the text in the "Incoming Mail Servers" textbox to bring up a dialog box. For "Server name" enter mail. where is your actual domain name without the "www." (i.e.- itempo.com). "Server Type" should be "POP". And enter your user name, click "OK".

In the "outgoing mail (SMTP) server" field either enter "mail.", or enter your dialup/DSL/Cable provider's outgoing server (some providers will require that you use their outgoing server).

Click "OK" in the lower right hand corner of the window to save the changes that you entered in the steps above.