For new people joining the live thread, here's how to manage the thread to stop emails:
At the top of the thread page, under the forums tab there is a list: Mark forums Read; Search Forums; Watched Forums; Watched Threads etc, select either watched forums if you want to adjust settings for watching forums, or select watched threads if you want to adjust settings for watching threads. If you click on all watched threads or all watched forums on the left under the list of watched forums or threads a option box will appear and you can select how to manage your settings.