Abstract: A mailbox having a mail carrier door and an owner's door with a signal flag moveably mounted thereatop to indicate the presence or absence of mail therein. A mechanism within the mailbox has a pair of slidable members mounted to a downwardly extending bracket with a flag rod extending through each member and moveable thereby. A pair of springs urge the first member toward the mail carrier door and the second member against the owner's door. A pivotable extension mounted to the mail carrier door is engaged by the mechanism to prevent opening thereof until the owner's door is open allowing the second member to slide therethrough releasing the extension.

Abstract: A double-door security rural mailbox having oppositely faced front and rear closures permitting safe, easy access thereto by the rural mail carrier and the owner of the mailbox. The mailbox has a locking mechanism including a key operated lock for locking the rear closure. The front closure is provided with a locking mechanism which allows the front closure to be freely opened and closed once by the mail carrier before securing in a locked position. Thereafter, the front closure may only be unlocked by unlocking and opening the rear closure. Once the rear closure is again closed and locked, the front closure may again be opened and closed once by the mail carrier before securing in a locked position.