I received a returned letter in the mail at work. The letter and post mark was from November of 2007. It was going to a local customer and was undeliverable. It was returned to us in April of 2011. We then received calls from several customers complaining about getting old bills in the mail. I wonder where it was for all these years? It is amazing that they wouldn't have just returned them all to us but actually delivered 2007 mail in 2011. Our DSO must have been really low that month since many didn't get their bills.