XFOR: IMC Events 4020, 4007 with Error 10048: WinSock Failed to Initialize

In a network environment where Exchange Server is configured to use Microsoft Proxy Server 2.0, the Microsoft Exchange Internet Mail Service may fail to start and logs the following two Event IDs in the application event log:

For Exchange Server to use the proxy features of Proxy Server 2.0, it must bind and listen on port 25 of the proxy server. The Exchange Server Internet Mail Service is attempting to bind to the listener socket for port 25 on the proxy server, and is failing. This usually indicates another service is already bound to port 25.

Verify that the Windows NT SMTP service is not running on the proxy server. The SMTP service will grab and bind to port 25, preventing Exchange Server from using the port. Verify that no other service or application is using port 25 of the proxy server. NOTE: Some customers have found their anti-virus product a contributing factor. Disable the anti-virus product on the proxy server and attempt to start the service. If this works, please contact the anti-virus vendor for further assistance.