The Sending Backlog Drilldown page shows you a breakdown of the information from the Sending Backlog graph on the Deliverability Dashboard.
How to get there:
In the Sending Backlog section of the Deliverability Dashbord, click view data.
To select a different MailStream
Click the MailStream drop-down list and then select the MailStream you want. The list contains all the MailStreams you have permission to view.
Column Descriptions
Domain: The name of the domain with pending recipients.
Total: The total number of pending recipients.