a slot, usually covered with a hinged flap, through which letters, etc are delivered to a building
a private box into which letters, etc, are delivered Also called (in Britain and certain other countries) letter box
2.
(mainly US & Canadian) a public box into which letters, etc, are put for collection and delivery Also called (in Britain and certain other countries) postbox
3.
(on a computer) the directory in which e-mail messages are stored; also used of the icon that can be clicked to provide access to e-mails
Word Origin and History for mailbox
n.
also mail-box, 1797, "box for mailbags on a coach," from mail (n.1) + box (n.1). Meaning "letterbox" is from 1853, American English.
mailbox in Technology
1. A file belonging to a particular user on a particular computer in which received electronic mail messages are stored ready for the user to read them. A mailbox may be just an electronic mail address to which messages are sent and may not actually correspond to a file if the messages are processed automatically, e.g. a mail server or mailing list. 2. A destination for interprocess messages in a message passing system. A mailbox is a message queue, usually stored in the memory of the processor on which the receiving process is running. Primitives are provided for sending a message to a named mailbox and for reading messages from a mailbox. (1994-10-20)