I have run into a very strange issue that is throwing me for a loop. We have deployed an Exchange 2010 SP1 server that sits behind TMG. The Exchange server is a single server configured with basic auth for Outlook Anywhere. TMG is configured using the 2 nic approach 1 nic in the DMZ and 1 nic on the LAN. Outlook anywhere, OWA, Active Sync, OAB download, Free/Busy etc are all working.
The issue is: Outlook users recieve password prompts about every 10 seconds, basically making outlook unusable. After hours of troubleshooting i am able to supress the outlook prompts by DISABLING Cahce Exchange Mode on the client. The issue has to be with the TMG server but it just doesnt make sense. Can anyone provide insight to why this might be occuring.
I have a feeling that it may have something to do with the listener, but the rules pass all test.