My inbox indicates that I have an unread Private Message for the longest time and for the life of me I can't figure out which one it is. I'm not motivated enough to go through and read all of my previous mail (I leave that for the Bored Moderators ;) but this constant reminder is sticking in my craw a little bit. I have sent messages to other posters who haven't retrieved them and eventually I just delete them, but apparently this mystery sender hasn't done the same with this particular message and perhaps thinks I am intentionally ignoring him/her/it, too busy or illiterate to read, and/or unwilling to pay their exhorbitant ransom - when really I am just plain baffled.
So, my question is: Is there any simple way to determine which message remains unread?