No idea, I've emptied my inbox since. However, the first message in my inbox now is from 2005 and it's from crummyrummy (yes, I checked ).
Honestly I can't remember. I delete all of my messages once I respond to them. I'm the same way with my email. I like my inbox neat and tidy. Hm, that sounds kind of weird.
I don't remember who sent my first PM. There've easily been over 25,000 PM's in my inbox/sent folders, over the years, so it's a little difficult to recall. lol