To setup a HTTPMail access from Microsoft Outlook Express, here's a step-by-step guide:
Run Microsoft Outlook Express
Click Tools, select Accounts...

Click Add, select Mail...

Enter your display name (friendly name):
Click Next
Enter your email address:
Click Next
Select HTTP as your mail server type and enter the URL to the HTTPMail service
(http://yourdomain:8080/MEHTTPMail).
Click Next
Enter your login name (full email address) and password:
Click Next
Click Finish
Click Close
You will be prompted "Would you like to download folders from the mail server you added?"
Click Yes.