I am running Exchange 2003 on server 2003 with sp2. In the last two days I have run into a problem related to the information store and the internet. I am running my incomming mail through a Barracuda spam filter and I have configured the receipient and delivery filters on the Exchange server. If I start the info store I almost immediately start to see latency on my internet connection. It becomes so bad that the internet is too slow to use. If I disconnect the exchange server or stop the info store, the internet connection returns to normal. I was suspecting NDR attack, but I monitor the queue (from the mailroot) and I cannot see any unusual activity. Is there something else I can looki at? Or look for?