Track Down a Spammer

An American business I legitimately had a momentary connection with immediately began to send my e-mail about 20 spam e-mails a day. They have ignored repeated unsubscribe requests. I should say that I do know how to create a mail rule to stop it, but I would like there to be some consequences for what they are doing.

You can't reply to the spam because the return addresses don't go to any mail box. You can't call the because they have no phone number that the public can reach. They also have no physical location anywhere near me and because of the nature of the business, if I traveled there I'm pretty sure I'd never get past a receptionist in the lobby. They've insulated themselves very well.

I complained to the FTC yesterday, but I don't hold up much hope because I regard them as incompetent. Look how successful the National Do Not Call List is.

I was thinking that I could look at the path their e-mail took and somehow figure out their hosting platform then inform the admin that they're violating the CAN SPAM act, but what I see in the path the letters took tells me nothing I couldn't see in the e-mail address. It corresponds to a Web site, but one that give you no way to contact anybody. Actually most of it is labelled "filter" and is gibberish.

Any ideas?