As you comment on an existing discussion post, you will automatically be set to follow the post to receive email updates regarding the subject topic.
You will receive email notifications with direct links to the post, as shown below.
If at any point you would like to unfollow from the email updates, you can do so from the email directly or from the discussion post. Clicking at the top right of the post, you will find the "Stop Following" link.
To view specific discussion posts, you may choose from the available filters to either view posts you are following, posts you have commented on, and posts that you have liked.
For more information on navigating through discussions, visit this article.