deliver mail to an unlocked or unsecured box which is located at a centralized mailbox installation. History Europe Private letterboxes or mail slots did not become popular in most of Europe until the mid to late 19th century, although they were used in Paris from the late 18th century. In 1849, the Royal Mail first encouraged people to install letterboxes to facilitate the delivery of mail. Before then, letterboxes 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. It is now on display at the new Wakefield Museum. North America In 1863, with the creation of Free City Delivery, the US Post Office Department began delivering mail to home addresses. Until 1916, mail carriers knocked on the door and waited for someone to answer. Efficiency experts estimated that each mailman lost over 1.5 hours each day just waiting for patrons to come to the door. To correct this problem, the Post Office Department ordered that every household must have a mail box or letter slot in order to receive mail. This requirement was phased in, starting with new delivery locations, around 1912. Slowly, homeowners and businesses began to install mail slots or attached mailboxes to receive mail when they were either not at home or unable to answer the door. The requirement was made mandatory in 1923. As early as the 1880s, the Post Office had begun to encourage homeowners to attach wall-mounted mailboxes to the outside of their houses in lieu of mail slots. Mounted at the height of a standing man, attached mailboxes did not require the mail carrier to lean over to deposit the mail. They also allowed the homeowner to keep outgoing mail dry while awaiting pickup by the mail carrier. To reduce the time required for the mail carrier to complete delivery when the front door of a home was located some distance from the street, it was proposed that individual mail boxes for residential or business customers be mounted curbside on fence-posts, lamp-posts, or other supports. While this idea was rejected for city mail delivery, it was adopted for rural areas. Curbside mailboxes located on a rural route or road and sited