Have you thought about putting up a mailbox that will stand out from the rest?
Have you thought about putting up a mailbox that is indestructible... one that could delay the progression of a tank?
There are guidelines from both the Illinois Department of Transportation and the U.S. Post Office that define such things as height and methods of installing mailboxes.
In order for your mailbox not to be a hazard to motorists, it must have light weight supports. This means no concrete pillars, I-beam "posts," stone aggregate held together by wire cage, etc.