When I unsubscribe from an email I still receive from the sender?

Also, it's possible you have multiple subscriptions with the sender. Some, when you unsubscribe will give you the option of unsubscribing to all emails or selecting the ones you want to unsubscribe to. Some are less accommodating. And, some of them seem to ignore the unsubscribe. I tried to unsubscribe to Cinemark emails for months. It got to the point where, when I'd hit unsubscribe, I'd be taken to a page that said I had no subscriptions and yet..... I just started marking them spam. Problem solved.

That is completely up to the sender. Some will stop sending emails immediately, some take quite awhile to update their system and stop sending, and a few seem to completely ignore the request.