Architectural Mailboxes Coronado Mailbox Black with Antique Nickel by Architectural Mailboxes®. $197.66. The Coronado sets the standard of beauty for the discerning homeowner. The body of this USPS approved post mount curbside mailbox is constructed of heavy 16 and 14 gauge galvanized steel that is fully powder coated prior to assembly for durability and long life. The black body is accented by over six pounds of solid die cast brass pieces in antique nickel finish that boast e...