Login Prompt rather than Screen on Web

I recently added two sites to our server config.

For example purposes, lets say its:

mail.domain.com

newdomain.com

Under the server config, basic, I enabled “Load Internet cofnigurations from Server\Internet Sites documents”.

All worked well, except, now users receive a windows style prompt to authenticate rather than the web based form of the webmail redirect.

Has anyone ran into this before? It works fine, but users complain because its different.

Subject: Login Prompt rather than Screen on Web

did you perhaps change your Session Authentication setting from single sign on to single server?