I recently configured an Exchange 2003 FE/BE topology on our internal LAN. I am getting Event ID: 1001 Source: EXPROX on the FE server in the application log.
I have found the related Microsoft Article:
It says that the FE should use basic authentication and the BE should use Integrated Windows Authentication.
However it does not say which virtual directories to configure in IIS on the BE server, so my question is which IIS virtual directories
on the BE Exchange server should be configured to use Integrated Windows Authentication to resolve this error 1001.