Check your subscription settings.

Click MY ACCOUNT at the top of the page > FORUM SETTINGS tab > scroll down and look for SUBSCRIPTION PREFERENCE

Make sure those are set to limit your emails.

Next, click "Thread Subscriptions/MyForums" near the top of the page and look at what you're suppose to be receiving subscription emails about. Make sure you scroll all the way to the bottom. Un-check anything you don't want to receive email about.