If you spend a week or so clicking the "unsubscribe" links in all of the unwanted emails you receive, you might be surprised with how manageable things become. I'd estimate that 99% of my unwanted emails respect the unsubscribe and don't send any more mail.
I highly recommend doing this. I got fed up at one point and started clicking unsubscribe in every non-personal or un-important email and, without all that much effort, my inbox became infinitely more manageable pretty quickly.
