[Carl n Susan]

Actually Bish, that stops email from future threads you post on. To cancel a existing subscription (and other subscription options) click on "User CP" in the thin brown ribbon near the top. Then look in the left pane for "Subscribed Threads". Click on htis and there you will find options to delete existing subscriptions (which you want) plus changing the MOC default of adding a subscription if you Post on a Thread .

If this isn't clear, let me know.