I recently was not able to recieve a PM because my mailbox was full. I thought I deleted my old messages, but I didn't delete any from the SENT folder, which is how everything got cluttered up.

Anyway, I had no way of knowing my PM box was full. If you go on LS1.com, they have a little bar that shows you how full your mailbox is.

I think we should have some sort of tool that shows how full people's mailboxes are. It doesn't have to be like the LS1.com bar, but even a little number would do ("PM: 10/70" would suffice).