A Christmas card sent by a pensioner to her nephew, two miles away, was delivered accidentally via Iran.
Edith Gover, 83, sent the greeting from a post box in Kingswood, Bristol, on 15 December to her nephew, who lives in nearby Bitton.
When the card arrived nine days later, on Christmas Eve, it bore a post mark from the Iranian capital Tehran.
Mrs Gover said she was surprised that the card made the 5,000 mile round-trip so quickly.
She said: "'It was quite a shock to think that the card had gone so far, but still managed to turn up at my nephew's house.
"Although the Post Office have made a mistake they certainly put it right very quickly."
A spokeswoman for the Royal Mail said: "It is very difficult to pinpoint, but it is more than likely it is an extremely rare case of where international mail has been attached in some way to inland mail."