Architectural Mailboxes Gentry Mailbox & Post KitSleek looks and several noteworthy innovations define the Gentry mailbox and post combination. Its clean design blends a variety of decorative accents on the mailbox and post to create a subtle, yet attractive look. Offered in four different colors, the unit is made from virtually indestructible and rustproof double walled polycarbonate plastic. The Gentry is also treated with an ultraviolet inhibitor so that the original color will retain its luster