Once you create a thread, or contribute to a thread - you get a notification anytime someone else contributes to the same thread. As it says in the email notification, "If you no longer wish to watch this topic you can either click the 'Unsubscribe topic' link found at the bottom of the topic". Otherwise, you will get an email if someone contributes after you.
....that is, if your service provider has not black-listed my service provider
