Looks like claassen.net got Joe jobbed. For the past two weeks or so some bastard spammer has been using claassen.net as their return-address domain. And so i've been getting a lot of bounce mails from all over the world. Fun.
First thing, of course, i made sure I wasn't compromised and my hosts was actually being used for the spam. From examining the headers of the messages bounced to me, it looks like the originating hosts are a bunch of zombies, so there isn't even any use in contacting the owners of the hosts that sent the spam.
For now, i'm just going to sit tight and filter incoming messages. Hopefully, the next rev of the zombie moves on to some other unlucky domain owner. And equally hopefully, i won't be on some blacklist because someone didn't check the origination of the spam. Ho hum.