mailbox

[meyl-boks] /ˈmeɪlˌbɒks/
noun
1.
a public box in which mail is placed for pickup and delivery by the post office.
2.
a private box, as at a home, into which mail is delivered by the mail carrier.
3.
Computers. a file for storing electronic mail.
Origin
1800-10; mail1 + box1
British Dictionary definitions for mailboxes

mailbox

/ˈmeɪlˌbɒks/
noun
1.
(mainly US & Canadian)
  1. a slot, usually covered with a hinged flap, through which letters, etc are delivered to a building
  2. 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 mailboxes

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.