Letter box

A letter box, letterbox, letter plate, letter hole, deed, mail slot, or mailbox is a receptacle for receiving incoming mail at a private residence or business. For the opposite purpose of collecting outgoing mail, a post box is generally used instead.

Letterboxes or mailboxes consist of four primary designs:

A "letter box", or "mail slot" in American and Canadian usage, is a slot, usually horizontal but sometimes vertical, about 30 cm by 5 cm (12 inches by 2 inches), cut through the middle or lower half of a front door. This style is almost universal in British homes and offices, but in the US is limited primarily to older neighborhoods in a few eastern cities. Most are covered by a or seal on the outside for weatherproofing. The flap may be closed by gravity, or sprung to prevent it opening and closing noisily in the wind. Some letterboxes also have a second flap on the inside to provide further protection from the elements. There may also be a small cage or box mounted on the inside of the door to receive the delivered mail. Mail slots are limited to receiving incoming mail, as most have no provision for securing and protecting outgoing mail for pickup by the mail carrier. (Sending mail from private addresses is not possible in the UK in any case, since the Royal Mail does not provide such a service.)

Wall-mounted or attached mailboxes may also be used in place of mail slots, usually located close to the front door of the residence. They are known as "full-service" mailboxes when they have provisions for securing outgoing as well as incoming mail. Attached wall-mounted mailboxes are still used in older urban and suburban neighbourhoods in North America. They are especially common in urban and suburban areas of Canada, where the curbside mailbox is rarely seen except in rural areas. Attached mailboxes are less common in newer urban and suburban developments and in rural areas of the United States, where curbside delivery or delivery to a community mail station (cluster mailbox, known as a bank of post boxes in the UK) is generally used.

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