No Dirt Off Of My Shoe

I have had issues with my mail carrier before and I have had a card or two lost in the mail but this is the first time that I have received mail with a shoe print on it. I was lucky enough that the sender had put the card in to a rigid top loader so there was no damage to the card but who picked up the mailer off of the post office floor and put it where it was supposed to go without even wiping off the dirt mark?