Single-door locking mailbox

A single-door locking mailbox that includes a housing having an open end and a door pivotally mounted to the housing for closing and opening the end. The door can be fully open, near closed but not locked or fully closed. A locking assembly, with a latch which can be placed in either the locked or unlocked position with a key, is attached to the door. A catch is attached at one end to the inside of the enclosure and has a camming surface and a hole at the free end. The camming surface deflects the catch over the latch when the door is pushed closed. The hole in the catch is positioned and configured so that it captures the locked latch when the door is pushed fully closed. The catch is resilient enough to be elastically deflected over the latch. A guard over the catch shields it from being deflected by a finger or tool inserted through the mail slot by a thief. The pivot axis of the door is located with respect to the center of gravity of the door assembly so that the door is held in the closed but not locked position by gravity. The geometry of the latch and catch are such that the closing force produced by gravity can not overcome the resistance produced by the latch and catch so the door does not spontaneously move to the locked position. After the mail has been deposited, the mail carrier pushes the door fully closed which causes it to reach the locked position.