A letter box, letterbox, letter plate, letter hole, mail slot or mailbox is a receptacle for receiving incoming mail at a private residence or business. For the opposite purpose of collecting outgoing mail, a post box is generally used instead. Letterboxes or mailboxes use the following primary designs:
A slot in a wall or door through which mail is delivered (through-door delivery)
A box attached directly to the building (direct-to-door delivery)
A box mounted at or near the street (curbside delivery)
A centralised mail delivery station consisting of individual mailboxes for an entire building
A centralised mail delivery station consisting of individual mailboxes for multiple recipients at multiple addresses in a particular neighborhood or community
