Microsoft OWA with OMA on Exchange 2003
From Swivel Knowledgebase
OWA and OMA on Exchange 2003 Integration Notes
the following Microsoft knowledge base article might be of interest:
http://support.microsoft.com/kb/817379
Article Summary
When you try to access a Microsoft Exchange Server 2003 computer by using Microsoft Office Outlook Mobile Access or Exchange ActiveSync, you may experience connection or synchronization problems. These issues can occur if either of the following conditions is true:
The Exchange virtual directory on an Exchange back-end server is configured to require SSL.
Forms-based authentication is enabled.
However, these issues do not occur if these same conditions are true on the Exchange virtual directory on a front-end server.