In the small mountain town I grew up in in the US, we didn’t have home mail delivery (they still don’t) because of too much snow not being compatible with mailboxes.
I live where this isn’t a problem, but I know folks who lose mailboxes to plowing. If I lived there, I’d mount the box on a simple farm gate, hinged five or six feet from the road. The hinge would lean toward the road, so gravity would swing the box back to the road. The plowing would brush back the box, but not break it. The box would be out of service for a few days, but when the snow melts, it swings right back into place.
This thread reminded me of an old friend whose mailbox was repeatedly knocked down (by cars, not plows) due to a combination of lousy road planning and poor road maintenance. He eventually decided he had had enough. He mounted a new box on a piece of pipe buried in concrete. The mailbox still got hit, but he was happy knowing that the cars were worse off than the mailbox. AFAIK he never suffered any repercussions.
ETA: thanks to Chimera for the memories! 
[QUOTE=chique]
My favorite (likely apocryphal but still amusing) snowplow/mailbox story for 25 years has still been this one:
Guy got tired of his mailbox getting knocked over so he went to the county and hired surveyors to determine his property line. Two feet back from his property line he dug a 3’6"x2’x2’ hole. He installed a 4’x2’x2’ concrete post…
The next snowfall the plow caught that 6"x2’x2’ block of concrete and spun around in a little ciricle. Hate and discontent ensued but the property owner won…
That’s the normal solution, but impractical in areas where driveways are, in and of themselves, 1/2 mile long. What a bunch of shit.
You don’t have to be a rocket scientist to drive a lawn mower/salt/sand/plow truck and most of the drivers really don’t care if your poor mailbox takes a hit. In our rural areas those idiots caused so many complaints that counties finally gave in and provided break-away mailbox stanchions. There’s a vertical post inside the property line; the mailbox is welded to an extended horizontal pipe; and inbetween the vertical and the horizontal resides a hinged 45 degree angled part. After a heavy Minnesota snow there are a bunch of snowplow-hit mailboxes pointing to the sky but they are easily pulled down again for mail delivery.
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you’re in minnesota, where they have REAL snow.
down here in central indiana if we got as much snow as you guys get up there, the whole damn state would shut down. talk about wimps…
I have a suggestion for all of you. I have seen a box that was mounted on an 8" or so I-beam post which was welded to a large and heavy wheel. I bet that sucker weighs 300 pounds. Big enough to resist most attempts at abuse, but would just slide out of the way if hit by a plow.