I simply use the properties option on spam mail, found out where they came from and go directly to their host ISP with a complaint about one of it's users.
Most companies seem to be easily reachable and quick to remove the service of the offender.
I had 4 spammers shut down this week alone. All of them were either using invalid return addresses or none at all. I figure as long as they want to invade my mailbox, I can shut them down. I look forward to your reports daily.