If your domain with us for example is mydomain.com then your settings should be as follow:

Incoming mail server:   mail.mydomain.com
Outgoing mail server:   mail.mydomain.com

In addition, you need to make sure authentication is enabled and the outgoing port number is changed to "2525"

Please reference the following knowledgebase on instructions on configuring Outlook and Outlook Express.

http://support.everplanet.com/?_a=knowledgebase&_j=questiondetails&_i=58

http://support.everplanet.com/?_a=knowledgebase&_j=questiondetails&_i=59