To configure your client manually:

1. Open Outlook or Outlook Express.
2. Click the 'Tools' menu, and select 'Accounts...'
   
   
   
3. Click 'Add,' and then click 'Mail...'
   
   
   
4. Enter your name in the 'Display name:' field, and click 'Next.'
   
   
   
5. Enter your full email address (username@yourdomain.com) in the 'Email address:' field, and click 'Next.'
6. Enter 'mail.username.com' in the 'Incoming mail (POP3, IMAP or HTTP) server:' field. Enter 'mail.yourdomain.com' in the 'Outgoing mail (SMTP) server:' field.
7. Click 'Next.'
8. Enter your username (including '@yourdomain.com') in the 'Account name:' field. Enter your email password in the 'Password:' field, and click 'Next.'
   
   
   
9. Click 'Finish.'
10. Highlight 'mail.yourdomain.com' under 'Account,' and click 'Properties.'
    
11. Click the 'Servers' tab, and check the box next to 'My server requires authentication.'
    
    
    
12. Click 'OK.'