HI,
MSN Hotmail no longer supports Distributed Authoring and Versioning (DAV)
for free user accounts. Outlook Express uses the DAV interface to connect to
Hotmail. Only paid Hotmail accounts will work correctly with Outlook
Express. If you configured Outlook Express or Outlook to access your Hotmail
account before DAV support was ended, you may still be able to use Outlook
Express to open a free Hotmail account. However, eventually Hotmail will no
longer support DAV for all free Hotmail accounts.
I've been able to use the accounts I've added before DAV support was
discontinued and they work just fine. Check out Microsoft's KB article
878462 for more details.