It's an innocuous act that we've all done before and will do many times in the future, although perhaps with a little more care after reading this story.
Placing a letter in the yellow La Poste mailboxes is a harmless act for 99.99 percent of the time but it went horribly awry for a 31-year-old physiotherapist in a village in the south east of France.
After visiting her parents for lunch in the village of Peipin near Digne-les-Bains she went to post a letter in the post box but as she pulled her hand out of the mailbox the top part of her left middle finger was severed by the metal flap and fell into the box, La Provence newspaper reported.
Firefighters and paramedics were called to the scene and the post box had to be smashed in so they could retrieve the severed part of the finger.
The unfortunate woman was rushed to hospital at Aix-en-Provence, but surgeons were unable to re-graft the part of the part finger back on.
As the picture above shows, most post boxes in France have metal flaps that open and close when letters are dropped in. It is not clear whether there have been other cases of people loses parts of their digits when posting letters.
Take care posting those letters in future.