a week ago we experienced a really sweet problem at a client of ours. They are a school with around 1200 users, and everyone of them has auto forwarding for all mail activated. We use Exchange 2010

Now a few of the users where able to make NDR loops by adding 2 different, wrong, destinations. We had around 80k mails sent within a few hours. Not very practical.

My question is, does anyone know a good way to prevent something like this.

I have found 2 ways, which both fail for their own reasons

1. We could manage the auto forwarding on the exchange host itself, which should prevent this looping problem someone said. But 1200 Users, not on my watch.
2. There is a Powershell script out in the wild which should work against that, but my employers want something more "professional"

Thank you very much for your support

Linus