CONCEPT A - CLOTH BAG MAILBOX The three bags can be labelled with the addresses of each of the three flats in the building (G, 1 and 2). The yellow sign on top has the mailbox sign (an envelope icon) and the main building address. The flaps can be lifted to drop in or take out mail. The cloth has net-like perforations (unclear from prototype) which show if there is mail in the bag.

CONCEPT E - TABLE MAILBOX The stopper for the horizontally hinged door -- which converts to a mail sorting table -- can be seen jutting out at the bottom. The rectangular slit above the yellow mail sign (with building address) receives mail from the postman. See photos below for more views of concept E.

CONCEPT E - The user unlocks and pulls open the horizontally hinged door to take mail out.

CONCEPT E - Door converts to table for sorting out mail, resting on the stopper.

CONCEPT H - LOW COST SEGREGATOR The three compartments are marked with the number of each floor/flat and the main address of the building is displayed on the yellow sign on the face of the mailbox. The folding lid is an improvement on the simple flat lid in the concept sketch, and occurred to me as I constructed the prototype. Mail is dropped in and taken out via the same opening, so the box cannot be locked.