How to "Undo" Mark All Messages as Read

[Mikee]

I am using Microsoft Office Outlook 2007.

I have accidently selected the "Mark All Messages as Read" under EDIT but
want to undo it. Is their anyway to do this?

 

[Vince Averello [MVP - Outlook]]

I don't think you can reverse it since Outlook doesn't know which messages
to mark as unread once they're marked read.