If you have built up a sizable list, it is possible someone has tried to turn you in to your ISP as a spammer. Luckily you are using software such as AWeber or iContact that keeps track of people who are double opting in or who have purchased from you. Therefore, you are safe and legal and you cannot get into trouble for spam.
However, I’m sure you have joined a list and then wished you did not join it because you find the emails from the person to be very spam-like. I received an email that said something like, “Did you try to call me at 3am? If not sorry for bugging you, but someone called and I missed the call, if you did then click here.” This is obviously not true, everyone he sent that to did not try to call him at 3am. This is an unethical use of the trust that person gave him by sharing an email address and opening his emails. This looks very much like spam, but legally since I joined the list, it is not spam.
My point is that while your subscribers asked to join your list and asked to receive emails from you, do NOT take advantage of their good will by doing such dishonest things as this. As honest and ethical Internet marketers we hold ourselves to a higher standard. Maybe we’ll miss out on a few dollars due to having ethics, but at least we can sleep at night, right?
If you are complying with the laws regarding spam you can easily defend yourself against these complaints by subscribers who have forgotten they subscribed or who do not totally understand the law. Permission-based marketing is a special form of marketing and one that we should work hard to keep honest.