At top of page go to 'Forum actions' (under the C of Charlton) then go to 'general settings' about half way down the page is an option for how to interact on threads change this to 'through control panel only' then emails should stop for new threads and you will only get emails if somebody posts to an old thread that you have commented on.
Or you could just not use your actual email when registering for things and instead use a disposable email address.