MailPro anti arson mailboxes and anti arson letterboxes.mpg 

I've got a better one. It's a steel lined porch with 3 doors. The outer one is open and the letterbox is in the middle one and the inner one is thick steel and goes to the house. The perpetrator pours the flammable stuff through the letterbox and light it. Heat sensors cause the outer door to shut and the middle door to open and the flammable liquid fills the space, burning the perpetrator alive! Muahahahaa that'll teach that letterbox arsonist!