Go to the following menu:

Tools --> Accounts then Add --> Mail in Outlook 98, 2000, and Express 4 and 5.

Tools --> E-mail Accounts then Add --> Mail in Outlook XP and 2003

Fill in the correct information as indicated below when prompted:

Full Name: your full name
Email Address: yourname@yourdomainname.com
Incoming (POP3) Mail Server: yourdomain.com
Outgoing (SMTP) Mail Server: yourdomain.com
Account name: Supplied Username.
Password: Supplied Password.