LETTERBOX

UK and ANZ, US mail slot [noun] [C] - a rectangular hole in the door or in a wall near the entrance of a person's house, through which letters, etc. are deliveredI tried to push the package through the letterbox.See picture: DoorsA letterbox (US and ANZ also mailbox) is also a box outside a person's house, into which letters, etc. are put when they are delivered.Letterbox is another word for postbox.