Can't re-download (POP) after marking Unread

Perhaps I am mistaken as I haven't used the old SM in a while, but I seem to remember that this worked in SM15? If you marked a message as Unread in web mail then Outlook would pull it down again upon Send/Receive.

This does not work in SM 16 (tested on 2 different servers 16.3.6677 & 16.3.6649). Is this by design or a bug, if by design is that something that can be re-instated?