The one-click unsubscribe law (sometimes referred to as the "one-step unsubscribe rule") is part of CAN-SPAM. The CAN-SPAM unsubscribe rules include that a recipient be able to effectuate their opt-out with a one-click unsubscribe, whether that is by replying to the email or by visiting a single web page. The one-click unsubscribe law is part of our Federal law, and so applies to any and all mailing lists and mailing list email.