Definition of letter box

The term "letter box" has its roots in the evolution of communication methods. In the 1850s, the UK Post Office introduced a system for delivering letters through letter boxes, small rectangular openings in the exterior walls of buildings where mail could be inserted. The name "letter box" is a combination of two English words: "letter" and "box." It refers to the small, typically cast-iron receptacle that is mounted on a wall or pole for the deposit of letters and other mail. The earliest letter boxes were simply open recesses in the exterior walls of buildings, but following the widespread adoption of new mail delivery methods in the 19th century, a need arose for standardized and secure letter boxes. The first true letter box was designed by Royal Mail Surveyor Sir Rowland Hill in 1852. His design, known as the "pillar box," was an improvement over earlier letter boxes due to its round shape, tilting door, and locking mechanism that provided added security. Since then, the letter box has become an iconic feature of the urban landscape, particularly in the United Kingdom where they remain a familiar andrecognizable part of their postal heritage. Today, the term "letter box" is used not only in the narrow sense of the physical receptacle, but also more broadly to refer to the wider concept of the postal system and the practice of sending written communication through it.