Dear Tom, Following your wonderful article posted on http://isaserver.org/pages/article_p.asp?id=1325 1. I have checked to see if my isp block port 135. when I type the telnet <ip> 135 I get a response back so it should be fine 2. ISA is behind a nat device, so I forwarded tcp 135 to external face of ISA 3. did what you suggested for adding registry key to exchange and restarted IIS admin service and exchange system attendant which restarted depending services too 4. created the exchange rpc rule 5. Created an outlook profile, but every time I load the outlook I get the connection to Microsoft exchange server is unavailable. Outlook must be online or connected to complete this action 6. I monitor ISA logs from my home ip address and the only thing shows up is ISA - TCP - - 3647 63 0 228 0x80074e24 0x0 0x0 Firewall 11/13/2005 2:16:12 PM 192.168.0.11 135 Exchange RPC Server Closed Connection Inbound Exchange RPC External Internal - - There is no initiated connection. Only closed. 7. it is outlook 2003 sp2 on xp sp2 connecting to exchange sp2 behind isa 2004 sp1 both on server 2003 sp1 Thank you for help. If anyone else got a suggestion I would appreciate it All mail to and from this domain is GFI-scanned.