Issue with a mailbox Folder report

Our Director of marketing wants a report for details of all folders in mailboxes that contain Contacts (or named Contacts).  The report works great, and contains almost all of the data that we want.  We are using the canned (default) report for Mailboxes - Folder Inventory from the Insights Library (and we are running the latest version of UCA).

The report shows the display name of the mailbox owner, but doesn't show the email address.  I've tried to add it - but it's not working.  Any idea how to leave the display name of the mailbox owner there, but also add a column for email address to the report?