Well known fact about Scientologists: once they have you on their mailing list, you'll never get off. Actually, it's probably a good way of finding out if there is an afterlife, because if anyone's got a way of contacting people on the "other side", it'd be Scientology's marketing department...
Traditionally, you took Scn's marketing mailshot's reply-paid envelope, sellotaped it to a brick (or just stuffed it with all your other junk mail), and put it in the post. With email, there really isn't that option.