Proxy server authentication

We use Microsoft Proxy Server 2.0 in our DMZ. It passes web mail requests to the internal Domino server behind the proxy server.

In order for our users to authenticate through the proxy server, the user's NT domain password and the Notes Internet password must be the same. Even though the normal Notes client password might be different.

Is there any way we can setup our security so that the NT Domain password and the Notes Internet Password can be different?

Here is an answer that was supplied by one of our "backup experts" (Frederic Dahm of Lotus) who helps me out from time to time.

"We use Microsoft Proxy Server 2.0 in our DMZ. It passes web mail requests to the internal Domino server behind the proxy server." Fine. No problem with that.

"In order for our users to authenticate through the proxy server, the user's NT domain password and the Notes Internet password must be the same. Even though the normal Notes client password might be different." Yes. That's quite possible.

"Is there any way we can setup our security so that the NT Domain password and the Notes Internet Password can be different?" Why don't they set up the Domino server with IIS and use the ISAPI filter for single sign on? This sounds to me like it would be the best solution, given the requirements of the Microsoft proxy server.