Various privacy, theft-protection, vandalism resistance and corrosion-resistance test requirements.When positioned externally, the post box should not allow more than 1% total capacity water ingress from natural precipitation or moisture causes.Mounting height of between 0.7 and 1.7 m for the aperture.The internal volume must able to hold at least a 40В mm high bundle of C4 envelopes.Envelope size C4 (229В mm Г— 324В mm) must be deliverable without bending or damage.The European standard for letter boxes, EN 13724:2002 'Postal services вЂ“ Apertures of private letter boxes and letter plates вЂ“ Requirements and test methods', replaces earlier national standards such as BS 2911:1974 'Specification for letter plates' or DIN 32617. ( May 2017) ( Learn how and when to remove this template message) Please do not remove this message until conditions to do so are met. Relevant discussion may be found on the talk page. The neutrality of this section is disputed. Collins of the Barlet-Collins Glass Company in Sapulpa, Oklahoma. One design was the visible mailbox (because it was made of transparent glass) with a flip-up aluminium lid produced during the first part of the 20th century by George F. In the US, wall-mounted or curbside mailboxes that are only designed for receiving incoming mail are known as 'limited-service' mailboxes, while mailboxes equipped with a mechanism for notifying the postman to collect outgoing mail from the mailbox are known as 'full service' mailboxes.ДЄ number of designs of letterboxes and mailboxes have been patented, particularly in the United States. ДЄt one time, nearly 843,000 rural Canadian residents used rural (curbside) mailboxes for private mail delivery, though Canada Post has since required the installation of community mailbox stations for many rural residents.

Although the United States Postal Service (USPS) has general regulations stating the distance a letter box may be from the road surface, these requirements may be changed by the local postmaster according to local environment and road conditions. In the US and Canada, rural curbside mailboxes may be found grouped together at property boundaries or road/driveway intersections, depending upon conditions. These receptacles generally consist of a large metal box mounted on a support designed primarily to receive large quantities of incoming mail, often with an attached flag to signal the presence of outgoing mail to the mail carrier. Rural and some suburban areas of North America may utilize curbside mailboxes, also known as rural mailboxes. 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. They are especially common in urban and suburban areas of Canada, where the curbside mailbox is rarely seen except in rural areas. Attached wall-mounted mailboxes are still used in older urban and suburban neighbourhoods in North America. They are known as 'full-service' mailboxes when they have provisions for securing outgoing as well as incoming mail. Wall-mounted or attached mailboxes may also be used in place of mail slots, usually located close to the front door of the residence. (Sending mail from private addresses is not possible in the UK in any case, since the Royal Mail does not provide such a service.)ДЄn attached or wall-mount letterbox, with a hook underneath for newspapers 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. There may also be a small cage or box mounted on the inside of the door to receive the delivered mail. Some letterboxes also have a second flap on the inside to provide further protection from the elements.

The flap may be closed by gravity, or sprung to prevent it opening and closing noisily in the wind. Most are covered by a flap or seal on the outside for weatherproofing. This style is almost universal in British homes and offices, but in the US is limited primarily to urban areas.

2 Letter box standards and constructionДЄ 'letter box', or 'mail slot' in American and Canadian usage, is a slot, usually horizontal but sometimes vertical, about 30В cm by 5В cm (12В inches by 2В inches), cut through the middle or lower half of a front door.

Letterbox box