By default, you will be emailed if someone responds to a post that you started. If you find a post or board topic interesting, and want to get an email when a new topic or reply is created, you can subscribe to it.
To subscribe to a post, board, or article:
After you open a discussion board or Shared Knowledge Base area, you will see a list of labels on the right-hand side. If you want to be notified of all posts or articles that apply to, say Data Integration, select the label from the list. In the header that appears above the the posts or articles, you'll see a link which allows you to subscribe to that label.
To manage your subscriptions, select your avatar and then My Subscriptions.