Microsoft Internet Security and Acceleration (ISA) Server 2000 RPC Filter Blocks Outlook Traffic from Computers Running Windows Server 2003 Service Pack 1 (SP1)

Outlook 2003 running on Windows Server 2003 Service Pack 1 cannot connect to an Exchange 2003 server through ISA Server 2000. This problem may also affect earlier versions of Outlook.

Windows Server 2003 SP1 makes significant changes to the Remote Procedure Call (RPC) service. Some of the changes may cause conflicts with ISA Servers RPC filter (rpcFltr.dll). As a workaround, disable the RPC filter. Install this update to fix this issue without disabling the RPC filter.

Requirements:

Windows 2003 Server