This problem happens because your version of Outlook Express is set up to use Secure Socket Layer (SSL), which the domain does not use.
To fix this problem, open Outlook Express, and click:
- Tools
- Accounts
- Then click on your mail account connection and click Properties
- Then click Advanced
- On this screen remove the checks from the boxes This server requires a secure connection for both Outgoing mail (SMTP) and Incoming mail (POP3).