Post box (British English and others, also written postbox), or mailbox (North American English and others) is a physical box used to collect mail that is to be sent to a destination. Variants of post boxes for outgoing mail include:
Lamp box
Ludlow wall box
Pillar box
Wall box
Boxes where postal workers deposit incoming mail for the recipient include:
Letter box (in the US usually called mailbox), positioned near or on the mail recipient's home or place of work.
Post office box, (often abbreviated P.O. box or PO box), a box rented by the mail recipient to be an independent postal address, located in a post office or in the premises of a company offering such facilities. Self-service boxes are unlocked by the recipient, otherwise a postal clerk retrieves the mail.
A relay box is similar to a post or mail box, but totally locked; post office trucks deposit mail that is then retrieved and delivered by pedestrian mail carriers. In the United States, they are painted differently from collection boxes.