Backscatter from Microsoft Exchange

As I have talked about before, backscatter is an annoying menace. Backscatter messages are sort of "ghost" bounces that come back to you, from sites that you've never sent mail to. It typically happens because a spammer is forging your email address or domain in spam, and the receiving mailserver is configured in a way that allows it to accept all mail before validating whether or not that mail can be configured. I get thousands of these "backscatter" bounces everyday, and, to put it bluntly, they suck.