What I'm saying is that usually, there is no legit address for it to bounce back to. Apparently this one spammer rotates through their list of e-mails to spam as the list of senders.
And how did they get access to your work email addresses to use them to send spam??? I've heard of viruses doing that (mydoom etc.), but just to send spam to other people???
I keep on getting spam from some online magazine...I bounce it back, it comes by a different address...I unsubscribe from what I haven't subscribed to, and it still comes...