Spam problems

This morning a spammer somewhere seems to have used my main email address as the return address on a whole bunch of random spam that has been sent out from all over the place. As such I have around 3000 undeliverable mail responses flowing into my in box. No doubt this will now have knock on effects with ISPs who use DNSLB type systems as my domain is being used by spammers again.

What’s the best way of dealing with this kind of problem?