Hi All, Iam Using ISA in firewall mode and using web publishing. Now i want to go for exchange server 5.5 with x.400 connector behind ISA. Can u please let me know the TCP ports required for allowing this scenario and do i have to run mail wizard on isa to accomplish this task. Another thing is that I am already using my extrernal interface of ISA for webpublishing and DNS entry of my webserver say some test.com is pointing to my External Ip of ISA. Now when i publish exchange i need to use Outlook web access so what should I do. What Valid Ip do I use for OWA. My webserver and exchange are on different PCs in my network. Please advice. Regards, vinay.