Hi! We deployed Exchange 2003 based on Windows 2003 AD. Our Windows XP user can access Exchange Server by using RPC over HTTP without any problem. We have Windows 2003 on which we installed Outlook 2003 with SP1. Our users will use RPC over HTTP from this client also. Unfortunately they cannot connect from this computer to Exchnage by using RPC over HTTP. They have no problem with OWA connections. Is there any restrictions for RPC over HTTP if a Windows 2003 Server is deployed as Outlook 2003 client? How can we fix this problem? Best Regards Mustafa