Letterbox: General info


An unusual Australian letterbox

A mailbox in southern Nebraska, featuring a red semaphore arm

From Wikipedia, the free encyclopedia

"Letterbox" or "Letterboxing" may refer to a video display or processing technique, see Letterbox.
"Letter box" may refer to a receptacle for outgoing mail, see Post box.

A letter box, letterbox or mailbox is a private box or slot for receiving incoming mail.

Two primary designs of letter boxes exist:

  • a slot in a wall or door through which mail is delivered
  • a box mounted near the street


Almost all buildings in the United Kingdom feature letter boxes. They are commonly horizontal slots approximately 12 inches by 2, found in the middle or lower half of a front door. Most are covered by a flap on the outside to offer a degree of weatherproofing. The flap may by sprung to prevent it opening and closing noisily in the wind. Many letter boxes also have a second flap on the inside to offer further protection from the elements. There may also be a small wire cage mounted on the inside of the door to catch the delivered mail.

The British Post Office first encouraged people to install letter boxes to facilitate the delivery of mail in 1849. Before then, letter boxes of a similar design had been installed in the doors and walls of post offices for people to drop-off outgoing mail. An example of such a wall box (originally installed in the wall of the Wakefield Post Office) is dated 1809 and believed to be the oldest example in Britain.

A number of designs of letter boxes have been patented, particularly in the USA.



To reduce the need for the mail carrier to walk extra distances when the front door is some distance from the street, letter boxes may be mounted on convenient posts at the property boundary. These boxes might have a slot to put the mail in, and a larger lockable door to take the mail out again. This design is popular where the distance between houses is larger, in countries like the United States and Australia.

On a property with several units or businesses, a letterbox with multiple compartments is often used. The mail carrier will have a key to a large door on one side that reaches all the compartments, and the tenants will each have a key to the door into their individual compartment on the other side.

In the U.S. some letter boxes are fitted with a semaphore arm that is raised to indicate to the mail carrier that there is outgoing mail in the letter box.

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