office door mailbox

Most are metal—commonly steel, iron, or galvanized steel—and many listings note rust‑resistant or powder‑coated finishes to improve durability.

They mount either through the door or to the wall. Many units are designed for simple installation and some include mounting hardware; through‑door models also specify compatible door thicknesses.

Slot heights and widths are typically about 1.8–1.9 inches by 9.8–10.2 inches. Interior capacities shown range from roughly 0.51 to 0.59 cubic feet.

Many designs include rain shields or flaps, drainage holes, and rust‑resistant or powder‑coated finishes to help keep contents dry and protect the exterior from corrosion.

Common anti‑theft features include one‑way delivery slots that block reach‑ins, internal metal baffles to prevent fishing, and keyed or combination locks.

Through‑the‑door models list compatible door thickness in their installation details; in the examples shown this is commonly about 1.7 inches (43 mm).