I am trying to setup Xeams as a firewall for incoming email only to an Exchange 2010 SBS Server. I am using a separate box for Xeams plugged into the same network switch as the exchange server running at IP 192.168.27.11. I added the Xeams computer to the domain. Pointed the firewall to send port 25 to the Xeams box (192.168.27.5). Gave Domain admin and Exchange admin access to Xeams. Xeams can ping the exchange server. The exchange server is always listening on port 25 and works fine without Xeams.

I setup Xeams SMTP Proxy only since I only want to filter inbound messages. Proxy port 25, Bind to 192.168.27.5, Server Host 192.168.27.11, Server port 25

I was able to setup Active Directory Integration and have the users added to Xeams.

Here is the problem.

No emails are received. Ran Xeams diagnostics and Server Communications shows 'Xeams could not connect to your corporate SMTP server'. All other tests, except Open Relay, passed. Open relay always fails when Server Communications fails.

Any suggestions would be greatly appreciated.