The man was found in a car in Västerås in eastern Sweden on Friday night busy opening Christmas cards. On closer inspection police officers found a red postbox belonging to the Swedish postal service Posten in the boot of his car.
Police were alerted to the man by a bystander who had spotted him push one of Posten's red boxes, which are put out during the Christmas period for the specific purpose of posting Christmas cards, into the boot of his vehicle.
"The thing is that there was a red mailbox at a store nearby. He probably hoped that there would be money among the Christmas cards, many elderly people send money for Christmas," said Martina Saghamre at Västerås police.
It was a private person who called the police after seeing a mysterious man budge into something nasty in the trunk of a car in the middle of the night. A while later, the police could arrest a man sitting in a car and opened the Christmas card.
The postbox was reclaimed by the police and officers ensured that any stolen letters were returned to their rightful place.
The police have now issued a general warning to refrain from sending cash with their traditional Christmas greeting.
"We would like to flatly discourage anyone from sending money with Christmas cards," Saghamre said.
According to Posten, it is extremely rare that the Christmas post boxes are stolen.
"This is the seventh Christmas season I have worked and I've never heard of someone stealing an entire postbox. Overall it is very seldom that we have problems with theft of Christmas cards," said Posten press spokesman Per Ljungberg.
Ljungberg backed the police call to refrain from sending money by Christmas post.
"There are many other ways to send money," he pointed out.
Last year, Swedes sent some 27.6 million Christmas cards. Projections for 2013 indicate some 25-26 million cards will be sent.