Section 8.12.1, Marking an Individual Entry as Unread
Section 8.12.2, Marking All Entries in a Folder as Unread
Navigate to the location of the entries that you want to mark as Unread.
Select one or more entries, then click More > Mark as Unread.
Navigate to the folder that contains the entries that you want to mark as Unread.
Click the Configure icon next to the folder name, then click Mark Folder Contents as Unread.