So today I got an automated abuse report (incidentally from http://junkemailfilter.com they seem to be up on things; Marc Perkel answered my questions right quick, and the automated message was clear and had all the info I needed to track down the problem.) It Turns out a free trial customer (who is no longer a customer) had a business of mailing 'opt-in' lists He even provided documentation of the sign up (But the message looked a lot like spam to me, and was blocked not because the reciever complained, but because it contained a link to a site that is blacklisted) Because he had documentation of the double opt-in, I'm not taking action against this customer, aside from terminating my business relationship with them, but I am changing the prgmr.com AUP to disallow all bulk mail (you can ask me for an exception if you want to run a mailing list)