Many of you have asked if there is a step by step guide for configuring RPC over HTTPS.
Well, the answer is a resounding Yes! Here is a link to the document on the Microsoft Site: http://support.microsoft.com/?id=833401
It makes note of the fact that the client computer must be running Microsoft Windows XP Professional Service Pack 1 (SP1) or above, and the update package that is described in the following Microsoft Knowledge Base article must be installed 331320 to an SP1 machine. You can also run the client machine with Windows Server 2003.
Your computer must be running Microsoft Windows Server 2003. You must install Windows Server 2003 on the computers that are running Exchange Server 2003. RPC over HTTP requires Windows Server 2003 and Exchange Server 2003. RPC over HTTP also requires Windows Server 2003 in a Global Catalog role.
Let me know how you get on!