Abstract: A mailbox kit is provided for retrofitting a standard mailbox. The kit includes a rear signal flap and hinge to allow the signal flap to pivot from a horizontal position to a vertical position to come into contact with the rear panel of the mailbox during mail insertion into the mailbox. The large, rear signal flap contains indicia for a homeowner to easily view from a remote location. The rear signal flap is joined to a wheeled control bar connected by a front linkage to the front door of the mailbox. Thus as the front door is opened the rear signal flap raises 90° alerting the homeowner that mail has been delivered.