Here is how to configure your email address in Outlook Express:

1)Click Start, point to All Programs, and then click Outlook Express
2)On the Tools menu, click Accounts.
3)Click Add, and then click Mail
4)Type Your name in Display name as you would like it to appear.
5)Type your email address people use to send email messages to you.
6)Type mail.domainname under incoming mail(POP3, IMAP OR HTTP) server as well as under Outgoing mail SMTP server.
For example if your domainname is example.com then type under incoming mail(POP3, IMAP OR HTTP) server, mail.example.com and under Outgoing mail SMTP server, mail.example.com.
7)Follow the instructions as above in the Internet Connection Wizard until you reach the Internet Mail Logon page
8)In Account name, type your POP3 service user name, followed by the domain, for example, someone@example.com.
In Password, type the password associated with your POP3 service e-mail account.
9)Click on properties button.
10)Enable: My servers requires authentication in servers tab
11)Enable: Leave a copy of message on the server in advanced tab.
12) Click Apply and then click OK.