The Inbox or any mail folder can be filtered to display only unread messages. By default, unread messages appear in bold in the message list. Newer versions Office 2007 In Outlook 2016, select the All drop-down at the top of the message list and then select Unread Mail . In Outlook 2016, 2013, and 2010, select the Filter Email drop-down in the Find group on the ribbon and select Unread . Search across all folders for unread messages ...