I have Outlook working with Exchange under Windows 7 mostly but I am still having trouble with authentication sometimes. I don't know exactly how our Exchange server is deployed, but it is on some sort of round-robin system. On my Vista system, which isn't on the domain, I can't access Exchange with no problems. While using it, I see authentication prompts from three different domain controllers (when it doesn't have cached credentials). Vista can authenticate to all three of these DCs with no problem, Windows 7 on the other hand, can authenticate to two of them fine, but can't authenticate with the third no matter what I try. I have tried both "DOMAIN\username" and "username@domain.com" formats for login. I have followed every thread I could find on this topic and still no luck. Very frustrating. Obviously, something is a little different about the third DC, but I don't know what. XP and Vista aren't affected, but it puts W7 dead in the water. Microsoft, please help - there are quite a lot of people having problems with W7 authentication with Exchange.

Anyone? I am still having authentication issues with Windows 7 on some domain controllers and Exchange (but as stated above it works with *some* DCs). I have scoured through Local Security Policy | Security Options and the sharing settings to no avail. Windows XP on the same machine worked fine, Vista on the same machine worked fine, Windows 7 doesn't.