RPC data may be blocked, and Outlook may not start in Windows Server 2003 with SP1
On a computer that is running Microsoft Windows Server 2003 with Service Pack (SP1), remote procedure call (RPC) data may be blocked by a Microsoft Internet and Acceleration (ISA) Server 2004 server or an ISA 2000 server that resides between the local computer and an Exchange server. When this problem occurs, Outlook may not start.
This problem occurs because the RPC filter in ISA Server is not compatible with the changes to the RPC protocol in Windows Server 2003 SP1.
When you enable the RPC filter in ISA Server, the RPC filter enforces strict compliance with a subset of the RPC protocol that is used by Microsoft Exchange Server MAPI communications.
Check out http://support.microsoft.com/?id=897716 for details and downloads.
