Getting subscriptions to forums that I DID NOT subscribe to

Is there a bug or something, because I am subscribed to over 300 threads to which 99% of them I never posted in the first place, why is that ? The threads that I did post on ends up getting deleted or get sent to my spam filter because I get flooded with emails that I never posted on in the first place! Going into my profile and making adjustments to the settings is confusing because I can only guess what the settings are exactly, is there a configuration page somewhere, a document or PDF would be real handy. Thanks