Hello, This is the message I get when I try to fill in either the externalurl or internalurl field on the Exchange (default website) in outlook web access tab of Client Access server configuration in management shell. So my first question: Why is the field there to fill in if you can't use it ? My second question: What is the significance of these fields? I guess they help determine what kind of SSL certificate to bind to the website, what else does it do? Assuming it drives certificate selectionthen that begs the question as to what what happens if internalurl and externalurl are completely different (and require different certs)..... IIS can only bind one cert to site, and how would it be able to tell the difference between internal or external traffic to begin with ? Any insight appreciated. Andre.

Exchange(Default website) is only use forOWA 2000/2003 and InternalUrl or EnternalUrl feature is only for OWA 2007.Why is the field there to fill in if you can't use it ? I guest is maybe just forget to remove in programing. Another answer for your question about IIS certificate,please reference this article How to Configure SSL Certificates to Use Multiple Client Access Server Host Names This topic explains how to use the ExchangeManagement Shell to configure your Secure Sockets Layer (SSL) certificates to use multiple hostnames.