I have Exchange 2010 SP1 configured with ForeFront TMG 2010. The TMG 2010 is in my DMZ and is NAT through my WatchGuard Firewall.
I noticed the other day that I was experiencing a huge amount of traffic to the external IP address, pretty much pegging my 15x15 circuit.
The only thing that I can do to stop this is to either modify the "Allow Web Access for all Users" policy to "disabled" or "All Authenticated Users" and then the traffic stops. Is there any other way to block this traffic? Otherthan just trace the IP's all day?