Configuring ISA Server 2000 to Support Outlook 2003 RPC over HTTP Part 1 Preparing the Infrastructure and Configuring the Fr Exchange Server 2003 allows Outlook 2003 clients installed on Windows XP Service Pack 1 and above full MAPI client access to Exchange Server 2003 resources using the new RPC over HTTP protocol. RPC over HTTP allows the RPC commands required for full Outlook 2003 MAPI client access to be wrapped or "encapsulated" in an HTTP header and passed through proxies that allow outbound HTT accessowaoutloookoverrpc in Adnan > New > networkwith adnaninfrastructurenetworkpartpreparing