If you want to enable notifications for Unity, click on the Settings button in the navigation bar and then on Notifications and Reminders.
Scroll to the bottom of the page and you'll see the Unity-specific notifications. Use the checkboxes on the right to send them to Learners and Admins respectively.
You can use the placeholders on the left to insert content that will by dynamically updated based on the recipient.
Unity Comment Posted Notification Email: Sends to all learners in the Collection.
Unity Comment Response Notification Email: Only sends to learners who posted in the comment thread.
Unity Question Posted Notification Email: Sends to all learners in the Collection.
Unity Question Response Notification Email: Only sends to learners who contributed in the question thread.
Unity Discussion Posted Notification Email: Sends to all learners in the Group.
Unity Discussion Response Notification Email: Only sends to learners who contributed in the discussion thread.