The mailbox flag apparatus provides a single unit mechanical combination which requires no modifications to a mailbox. The bracket of the apparatus is made of various materials of choice, which each provide slight flexibility, with memory, such that the bracket is positioned over the finished front edge and on the inside and outside of one side of the mailbox. The mounting force and daily use forces are thereby exposed to a large surface area, which increases mailbox and flag durability and reliability. The critical dimensions of the bracket, flag arm, and pivot location provide automatic gravitational pivotal elevation of the flag arm and flag, upon opening of the mailbox door, thereby signaling a user that a postal stop has occurred.