My 'Infected Items' folder in Outlook 2013 is showing one item - see attached. But there is nothing there. I have restarted Outlook several times and even rebooted my machine. But it's still there (or not there).

 

I could of couse simply say "mark all as read" but I'd like to know what is causing this - and whether there is, in fact, something dodgy but invisible in there that needs to be dealt with.

 

Any suggestions welcome - thanks.

It looks like you have 2 sort option on top to filter your results, All and Unread. Have you tried clicking both of them?