Our organization uses a Samll Business Server 2003. Although it came with ISA server (premium version), it did not have ISA server installed on the box for various reasons. To minimize security risks, I setup an edge ISA server on a different box filtering the traffic. It has been working like a charm. However, I have come across a stumbling block when I try to publish Outlook Web Access and Outlook RPC/HTTPs. Basically, ISA does not want to work with SBS 2003 if end to end HTTPS is used. I have to compromise on the SBS 2003 to not to use HTTPS (uncheck require encryption on the exchange virtual directories within IIS). Although the client connection to the ISA 2006 server's external interface is still encrypted, once the traffic passes ISA, it becomes HTTP only. And this is the only way that I can make it work. By the same token, I thought it should work on Outlook over RPC/HTTPS, but it doesn't.
Dose anyone have similar experiences with this setup? I really want to get to the bottom of it. I've been searching everywhere on the Internet with no luck. Thanks all in advance.