"... Centralized mail delivery: Neighborhood Delivery & Collection Box Units (NDCBU) are popular in home and office complex developments. USPS can help
plan centralized ..."
From: on Page 878, Architectural
Graphic Standards, Tenth Edition (Book only) Charles
George Ramsey, John
Ray, Jr. Hoke
Curiously, one new feature for homes this then creates are Package Delivery Vault without a letterbox. The idea here is that while the mail goes to the centralised mailbox, packages can be delivered to the home.