So, after years of having referrizer I am just learning that clients cannot actually unsubscribe from our emails. Yes, it does unsubscribe them via referrizer.. but referizzer does not communicate that with MindBody. So, the client will ultimately be RE-SUBSCRIBED, unless they log in to their Mindbody account and unsubscribe there. Which why would they do that? I am sure they assumed they unsubscribed when they hit the unsubscribe button..
So, that leads me to the ultimate conclusion that the unsubscribe button doesn't work with Mindbody users.