Exchange ActiveSync and Outlook Mobile Access errors occur when SSL or forms-based authentication is required for Exchange Server 2003
http://support.microsoft.com/?kbid=817379 Disable the forms-based authentication for the Exchange virtual directory To create a secondary virtual directory for Exchange that is based on steps 1 through 7 of the following procedure, make sure that forms-based authentication is disabled for the Exchange virtual directory before you make the copy. Before you follow these steps, disable forms-based authentication […]