Yesmail was recently sued by the FTC for violating the CAN-SPAM act. Specifically, for not honoring an unsubscribe request within ten business days. Apparently, they used a "reply to this email and we’ll remove you" kind of link. One of their recipients replied, but their message was accidentally spam-filtered by Yesmail’s email server. Something to consider for marketers who don’t use a one-click unsubscribe link in their campaigns. They settled with the FTC for about $50,000.