To follow posts in your course discussions, open the post, then move your cursor over the gray star icon in the upper right corner. Click "Follow".
The star icon turns blue to indicate you are now following this post. When you view this post in the discussion navigation pane, it also appears with a "Following" indicator. For more information about the various indicators in the navigation pane, see Reading posts on the Discussions page.
Receive daily email digests
To receive a daily email notifying you about new responses and comments on posts that you are following, click the Discussion tab in your course to go to the Discussions page.
In the "How to use edX discussions" graphic in the main area, click the check box next to "Receive updates". This graphic is shown only when you have not opened any posts to view.
Show only posts you are following
In the discussion navigation pane, you can lists only the posts that you are following, regardless of the topic that they apply to. To do this, select Posts I'm Following at the top of the topic list.