Go to 'Tools' -> 'Accounts...' -> 'Add...'

Display Name: (as you wish) ->
Email Address: (xxxx@domain.com) ->

My incoming mail server is a [POP3] Server.

Incoming Mail (POP3, IMAP, HTTP) server: [mail.yourdomain.com]

Outgoing Mail (SMTP) server:
[mail.yourdomain.com or your ISP SMTP server settings*]

Account Name: (xxxx@domain.com) (same as email address.
Password: as appropriate

Log in Using Secure Password Authentication is NOT checked.

Click 'Next' and 'Finished'

Click 'Properties' -> 'Servers' Tab

*Make sure 'My Server requires authentication IS checked ON if you're using our SMTP Server settings. Otherwise contact your ISP.

Click Apply, OK, OK.

and test the email. If it does not work, try your ISP settings for Sending email.