Fortune Affiliates checked for me, and was given information by the sender of the email indicating I had opted in to their list a month or so ago. However, the IP they say I signed up from was a cable modem in Rochester New York, far from my home. Whether it was someone else signing up my address, or if the opt-in information was completely fictitious I don’t know.
However, the good news is that I’ve stopped receiving the flood of messages.
Thanks David S and FA for checking this out for me.