The object of Mailbox is to be the letter carrier who delivers the most letters to animals' mailboxes. The game utilizes a dealer or leader to facilitate game play.

The game consists of 8 mailboxes, each with 4 animals' names and pictures on them, and several sheets of letters, which are to be delivered. The leader writes each players initials on a letter, distributes them to the appropriate players. Players search for the appropriate animal's mailbox, deposit their letter, and return to the leader for another letter to deliver, continuing until all letters are delivered. The winner is the player who delivers the most letters to the correct mailboxes.