Subscribing to the Discussion Board is a good way to stay notified of discussion activity.
You may subscribe to receive email notifications by clicking the "Follow" button on the Discussion main page. This automatically subscribes you to receive notifications of all new threads and all replies.
You may unsubscribe from receiving reply notifications for each individual thread by clicking on the thread and then clicking on the eye icon below the original message.
I hope this helps you optimize your discussion board experience.