Hi, all I have a owa 5.5. that needs to comunicate through a firewall with some exchange 2000 servers.I used :XCLN: Exchange 2000 Static Port Mappings (Q270836) <http://premier.microsoft.com/premier/library/default.aspx?path=/premier/kb/en-us/Q270/8/36.ASP?KBID=Q270836> to assign static ports, and enable them in the firewall. But is seems it wasn´t enough. It seems the e2k servers are still telling the exchange 5.5 to use some random ports, and the firewall is dropping this packets. The ports I set up in the e2k registry are: System Attendant: TCP/IP Port, TCP/IP NSPI Port Information store: TCP/IP Port MTA: RFC1006 Port Number, TCP/IP port for RPC listens Thanks for the attention. Danilo Dias