If you want alerts to updates in a discussion, you have the option to subscribe to it.

  1. In the Discussions List, click the drop down arrow beside the name of a forum or a topic. 
  2. Click Subscribe.
    cursor over the drop down arrow beside a topic, and over the Subscribe option
  3. In the Customize Notifications screen, select your Notification Method and click Save. 
  4. Click Subscribe.
    customize notification options

NOTE: You can also subscribe to topics in the View Topic view by clicking “Subscribe” beside the thread you want to receive notifications for.  You can also subscribe to a thread when posting a reply to it.