After trying out Microsoft Internet Security and Acceleration (ISA) Server 2006 on a test Exchange 2007 server I’d set up (running on VMware Server), I decided against using ISA Server 2006 with our Exchange 2007 setup, at least for now. In my testing, I found that ISA Server doesn't offer me much benefit if I deploy it in my demilitarized zone (DMZ) with a single NIC, and I'm not ready to use ISA Server to replace my redundant pair of Juniper Networks NetScreen firewalls. I have only TPC/IP ports 443 and 25 going straight to my Exchange server, so I don't think I'm really missing out on much using my current dual-firewall setup as opposed to a single-NIC ISA server. Furthermore, a big show-stopper for us is the fact that ISA Server 2006’s prebuilt forms don’t offer UPN logons as an option, and I haven’t been able to get a response from the Microsoft ISA Server team about how to hack this into the code.
