Abstract: A mail drop box includes four sides, a top and an open bottom, which together form a rectilinear sexahedron. A door on the top is slideably engaged in between a pair of opposed horizontally aligned channels for preventing the door from opening when the box is moved from a first vertical position to a second horizontal position. A plurality of brackets affix the box to a vertical surface, such as a garage door. Means for altering the height of at least portions of the sides are provided.