Mailbox (British English; also known as written mailbox), also known as inbox, mailbox, mailbox or delivery box (American English), is a physical box in which the public can store outgoing mail collected by agents in a country's postal service. The term "P.O. Box" may also refer to a private mailbox used to receive mail.

In 1653, the first mail boxes are believed to have been installed in and around Paris. By 1829, the post office box had been used throughout France. Poland's first public post office box was installed in Warsaw in 1842.

Originally installed on the wall of Wakefield post office, the post office box dates back to 1809 and is believed to be the oldest in the UK. It's on display at the new Wakefield Museum.

In the British Isles, the first red post office box was established in Jersey in 1852. The roadside wall post office box, which first appeared in 1857, is a cheaper alternative to the box, especially in rural areas. In 1853, Britain's first pillar box was installed in botchergate in Carlisle. In 1856, Richard Redgrave of the Department of science and art designed a magnificent column box for London and other big cities. In 1859, the design was improved, which became the first national standard pillar box. Green was used as the standard color for early Victorian PO boxes. Between 1866 and 1879, the hexagonal Penfold mailbox became the standard design for the column box, and red was adopted as the standard color for the first time during this period. The first box to be painted red was in London in July 1874, although all the boxes were repainted for nearly 10 years. In 2012, to celebrate the Olympic gold medal of GB team, the selected box was painted with gold. A man has been temporarily destroyed by graffiti. I drew a picture in the wrong town.

Russia's first public mailbox (PO box) appeared in St. Petersburg in 1848. They are made of wood and iron. Because these boxes are light and easy to steal, they often disappear. Later boxes were made of cast iron, weighing up to 45 kg