Outlook Displaying DisplayName and Email Address in reply mail after updating Outlook to 15.0.4745.1000

We recently patched out office environment and Outlook updated to version 15.0.4745.1000. Whenever a reply is sent, the previous sender and all of the recipients show below (as expected) but instead of just mail address, DisplayName and EmailAddress properties are shown. If sending to a DL, of say 70 users, this expands and shows all 70 users addresses and display names clogging up the feed - it looks like the below - 



does anyone know how to ensure that outlook only shows either the mail address or the display name?

Thanks