Open Outlook Express

From menu click: Tools -> Accounts -> Add Mail

in Display Name box type in: youraccount@yourdomainname.com This e-mail address is being protected from spam bots, you need JavaScript enabled to view it
click Next and type in: youraccount@yourdomainname.com This e-mail address is being protected from spam bots, you need JavaScript enabled to view it
click Next:
Incoming Mail Server: yourdomainname.com
Outgoing Mail Server: yourdomainname.com
click Next:

Account Name: youraccount@yourdomainname.com This e-mail address is being protected from spam bots, you need JavaScript enabled to view it
Password: yourpassword
click Next
-> click Finish

Double click the email account that you just created.

Click on Servers tag -> Check mark “My server requires authentication” -> click on “Settings…” button

click on “Log on using” radio button

Account Name: youraccount@yourdomainname.com This e-mail address is being protected from spam bots, you need JavaScript enabled to view it
Password: yourpassword

click on “OK”