caption: Slide 4 of 16: Another easy fix is cleaning and painting your mailbox. Stick with the classics: A shiny black mailbox is always desirable and signals a well-cared-for home. You can easily repaint a metal mailbox by sanding it, then priming with Rust-Oleum Professional Aluminum Primer. Wait several hours for the primer to dry, then apply Rust-Oleum Stops Rust Gloss Protective Enamel in Black to the entire mailbox; use the same formula in Sunrise Red for the flag.