Hi, I just published Exchange 5.5 (NT 4) on the ISA. I added TCP/IP Port in registry like this: for MS Exchange DC: TCP/IP Port 5000 and MS Exchange IS: TCP/IP Port 5001. On the ISA I setup RPC second connection to use 1024 to 65535. The outside client can't connect to exchange server. I had the similar problem when I setup using PIX, 'established' command to allow RPC protocol to use port 1024-65535 didn't work. I had to create 'access list' to open port 5000-5001. Is there anything wrong with setup? Thanks, Winoto