This morning, in the office mail, there was a letter for me. It was post marked from Madrid, Spain. It cost the sender 0.78 Euros to send. AND IT WAS SPAM! Not the kind of junk mail we usually get but the "I have millions of dollars to send you because your last name matches some dead guy's unclaimed riches" kind.
Steven pointed out that this proves that charging money for emails will not stop spammers.
There was no return address.