The Daily Summary is a notification email sent to all Commons members when new activity occurs in the communities they belong to. The summary is run daily and gets emailed out to the email on file in The Commons. Members are notified of new posts as well as comments made to posts they made or are following. The first 512 characters of the post will appear in the summary.
Managing your Commons notifications can be done by changing your account settings. You can change the frequency of your notifications, what type of activity you want to be notified of, and how you want to be notified when you are tagged or have a chat message.