Is someone on my domain sending out spam? Exchange Server is receiving a lot of failure notices
Posted on 2007-08-09
I set up some spam filtering software on an Exchange 2003 server and I have been monitoring the "bad mail" folder daily to make sure it doesn't block anything good. This morning I noticed litterally hundreds of "Failure Notice" emails from "MAILER-DAEMON" at many different domains. It appears all these messages say they originated from [random name]@[mydoamin].com. The server is not an open relay, and I am checking the queues for anything suspicious, but see nothing in the way of outgoing mail coming from my server.
Is this a sign that someone on the domain is sending out spam? What's the best way to track it down if this is the case?