Smothered with MyPoints e-mail

Some "friend" gave MyPoints my e-mail and I am being swamped in MyPoints e-mail. Can't stop their junk e-mail to me unless I first join then unsubscribe. If I join, I must first agree with a series of stuff that amongst which says that they may share some of my information (e-mail address) with some of their suppliers. I don't want this to happen as I will be put on another e-mail list. This is ludicrous, I want out!