Mailbox of Doom

About 16 years ago, when I lived in Lake Stevens, Washington, we had trouble with people smashing our mailbox and knocking it over. I got some 1/4 inch steel plate and welded up this 76 pound mailbox. I mounted it on a 7 & 1/2 foot steel I-beam cemented in the ground. Several people that decided to turn around in our driveway left some paint from their cars on the box.
After moving here, this box has gone through a variety of posts. The biggest risk to the post here is the snow plow. It will both knock the post sideways and up as it shoves snow up against it.

This is my latest post. It is double hinged so it will go up and down and side to side and the springs on the back will push it back.

The bad news is I didn't have any numbers on the support springs so I couldn't determine if they were strong enough to hold it up until it was installed. Worse, I came down with Cave Troll Flu right then and it sat there hanging for almost 2 weeks.

Now that I am mostly recovered, I proceeded to fix the problem. Since the Post office tells me they want it 42 inches from the ground, I stuck a 42 inch stick under the end of the box and measured the length of the springs. I cut two pieces of pipe 12 inches long and slid them inside the springs. This held the box up right at the correct height while still allowing the post hinge up when the plow goes by.

With it structurally sound, I got some paint and painted the whole thing white. The other mailboxes now look pretty sad.