How do you avoid mailbox vandalism?

The best way is to build a small concrete pillar with a built-in mailbox that has only a metal door with key and the flap for leaving the mail. For avoiding people tossing harmful things into the box, invert the flap so the letters must be pushed up instead of down, allowing only letters or thin objects to cross. You may also choose to drop off any mail with checks to a certified US mailbox rather than letting it sit in your box.