Exchenge 2k in a separate domain

[gzejer]

I have an exchange server sitting in its own domain behind a firewall. There are no users in this domain but everybody authenticates from an outside domain. I opened up the ports recommended by MS (25, 53, 80, 88, 102, 110, 135, 137, 139, 143, 379, 389, 445, 691, 3268) on the firewall however the outside users are unable to connect to the servers using MS outlook 2k Exchange configuration. They are able to use the IMAP or POP3 protocols. As soon as I open all ports on the firewall to the exchange server they are able to connect as Exchange users. What, am I missing? I understand that one of the ports is still closed when I enable the firewall security but which one?

 

[Serbtastic]

Run a netstat -a on your Exchange server while a client is connected and see what ports are being used.

 

[jrmjh]

I'm not sure if this was changed in E2K but with 5.5 the client opened a new High port with the exchange server after auth. In order to make 5.5 work you had to edit the registry to force exchange to communicat on a fixed port. But not sure if this is the case in E2K.