Here's one for the anal historian.
I have in my hands an appeal letter that TACF sent out regarding SARS. The letter is dated May 15th, 2003. It arrived marked "Return to Sender," yesterday. It has stamps dated June 10 2003, 17 March 2005, and April 27 2005.
I tip my hat the United States Postal Service. I can only assume it fell behind someone's desk somewhere and was recently found, and someone thought, "Well, better late than never." Either that, or it's been bouncing around the US postal system for 2 years. Each option is equally likely.