I remember someone in
Tightwad Gazette saying that they got so tired of kids taking out their mailbox that they bought two mailboxes, one regular sized and the other oversized. They put the regular sized box inside the big box and cemented between the two. Then I think they cemented the whole thing to one of the big redwood posts and sunk it in the ground with more cement. Looked pretty normal, but the next kid who thought he'd be smart and play mailbox baseball ended up with a broken wrist. Problem solved
If you're not willing to go that far (lol), have you checked with your local P.O. to see if you can get a dispensation to have your box on your house? I know that here, once it's moved to the road you can't go back to house delivery without petitioning.