A square or rectangular prism shaped box commonlly situated at the front of peoples houses mounted on a post or in a precut hole in the fence. A letter box can usaully consist of two different holes; a rectangular hole cut into the letterbox, which is where the postman or postwoman places paper messages encased in a an adressed envolope. The other hole is a round cylinder, where pointless paper, also known as junkmail, is inserted by the paper boy. On the letter box,it is very common to have the number that represents the house that the letter box is used for. Some letter boxes can be locked by a small padlock to prevent people from stealing your mail (this is highly recommeded if you live in a shitty/dodgy neibourhood). Most people like to decorate their letterboxes but is usually a very bad idea.
"hey ma! Im going out to get the mail from the letter box. ok?