The other day somebody wiped out my mailbox. It's a typical plastic mailbox, that mounts onto a 4x4 post.


The old post snapped off right at ground level. Instead of trying to dig it out, I've dug a new hole nearby. After talking with a neighbor, it turns out this type of thing happens a lot (lots of crazy/drunk drivers in the area, I guess). My original plan was to simply stick the post in the ground, and back fill with dirt.

Post in dirt
Post in dirt

I also considered using concrete.

enter image description here
Post in concrete

According to the Federal Highway Administration

Do not embed the post in concrete unless the mailbox support design is shown to be NCHRP 350 compliant when so installed.

So putting the post in concrete is out.

After the neighbors comment, I'm trying to think of ways to make the inevitable next repair easier. My first though was to fill the hole entirely with concrete, embed threaded rod in the top, and then use a bracket to attach the 4x4 post to the concrete.

Post on concrete
Post on concrete

I'd likely use a bracket similar to this one from Lowes.

4x4 Post Bracket

I'm worried that if another car comes along, the impact could actually bend or break the threaded rod, making it difficult to install a new post. So instead of saving myself time, I'd find myself digging another hole anyway.

Is it worth the extra time and money to install the mailbox using the post bracket, or should I just stick the post in the ground? Are there other common solutions that I haven't thought of?

After reading the USPS mailbox guidelines, I'm now thinking maybe I should build this a bit lighter duty. I'm now considering installing a post in the hole flush with the ground, then using a bracket to attach the above ground portion of the post.

Post in Dirt with breakaway
Post in dirt with breakaway

I'd likely use a bracket similar to this one from Lowes

4x4 bracket

This way if somebody hits the mailbox again, hopefully the in ground portion will be undamaged.

  • What about plastic nuts on the threaded rods, or some other plastic fastener that is strong enough to hold up to the weather, but would give way when hit? Jun 23, 2014 at 15:23
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    Turns out the USPS has some mailbox guidelines that are interesting. They say "Bury your post no more than 24” deep, so it can give way in an accident.", which I wasn't aware of (and would have saved me time since I dug a 4' hole, that apparently I now have to fill partially in). They also say "Don’t use potentially dangerous supports...", so sinking an I-beam is not an option, unfortunately.
    – Tester101
    Jun 23, 2014 at 15:35
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    There's something to be said for the idea of an entirely concrete post... so that the person hitting your mailbox has a REALLY BAD car bill... Jun 23, 2014 at 16:18
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    @TheEvilGreebo That might lead to some nasty legal action against me. Most of my recent research has shown that government looks out for the safety of the idiot driver.
    – Tester101
    Jun 23, 2014 at 17:07
  • Since all the rules are there to protect in case the mailbox itself is hit, I think a large decorative planter that's partially filled with concrete could be used to protect the mailbox from careless vehicles while leaving the mailbox itself in compliance.
    – BMitch
    May 9, 2016 at 1:09

6 Answers 6


Years ago, growing up on a rural farm in the midwest, my father solved the drunk driver mail box problem. He did this after drivers and snowplows took out the mail box several times.

He placed the mail box on a long arm that was cantilevered over a swivel post 10 to 12 feet off the side of the roadway. The design of the swivel post was such that the mail box arm would self return to the normal position if the snow plow would go by and gently push the box out of the way. On the other hand if a driver came by and made a direct hit on the box it would swing 90 degrees and latch into that position till one came to release the catch and let it return to normal position.

The "return to normal" mechanism worked by having springs pull down hard on the swivel part which was mounted against a V-groove seat on the post.

  • 2
    I'd like to see some photos or sketches of the mechanism. Though I fear this might draw unwanted attention from the neighborhood kids, who'll be tempted to use my mailbox as a strongman game to see who can whack it the furthest.
    – Tester101
    Jun 23, 2014 at 16:14
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    Another common mounting method for mailboxes in areas with high snowfall is on two chains in a "V" suspended from trees overhead. The snowplows whack it up out of the way when they go by, and it just swings back into place afterwards.
    – Doresoom
    Jun 23, 2014 at 17:43
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    @Tester101 My old colleague had his mailbox destroyed many times by teenagers driving by with baseball bats. He finally bought two mailboxes, a regular size and an over-sized. He put one inside the other, and filled the space between them with concrete. A few weeks later one night he heard a loud crack, someone howling in pain, others laughing, and a car speeding away. He found a destroyed bat on the curb next morning. Mailbox had minimal damage, and the beatings stopped. Apr 2, 2021 at 17:26

You can use a metal anchor that screws into the ground. You then attach your wood post to the slot on top of the anchor with lag bolts. It's sturdy, but still gives way if impacted.

See here: diymailboxes.com/how-to-install-a-mailbox-post-without-concrete/


You could screw a scrap piece of 2x4 or angle iron to the post and use that to lever it up out of the hole, along with some side blows with a sledge hammer. This should be easy to do; and you can then just set the new 4x4 into the same hole. Having a new 4x4 ready to go would also make the job easier.

Another approach would be to cut the new post about 6" or so above the ground, and dowel it together before setting. That way the dowels will break, but not the post. Treating the dowels with a preservative would enhance their life. I'd go with three 1/2" dowels about 5" long. I would NOT glue them so that they can be pulled out and replaced if the post is hit by a car.


SAND to the rescue.

No concrete needed. Bury an empty 6 or 8 inch tube two feet deep, and flush with the ground. Compact the soil around it. Then center and level your mailbox within the tube, and fill around the post with sand. Tamp the sand down too a bit, then cover lightly with sod.

Next time a drunkard hits it, you can vacuum out the sand and remove the broken post with no tools. Put the new one in and pour the sand back in and your mailbox is back immediately!

Here's a diagram using the same method for a fence post. With the high wind loads of a fence, you might want to surround the tube with concrete. But with a mailbox, it shouldn't be necessary.

enter image description here

Also, with a fence post, sealing the top with silicone will reduce the rate of wood rot. But if your mailbox is getting replaced often, it won't have time to rot.

PROTIP: Place some hollow tube caltrops around your mailbox. (just not on the street or your driveway. So when someone runs into it, they won't make it very far before their tires are deflated.

Then their insurance company gets to pay for your mailbox.

enter image description here

Here's a video how to make them: https://www.youtube.com/watch?v=v9DhM6G-hzU&feature=youtu.be

  • 1
    I'm not a fan of the caltrops near the mailbox. They look like they'd go right through the shoe of the person checking the mail.
    – BMitch
    Jan 23, 2016 at 2:39
  • Depends on the layout of the area. My mailbox is positioned such that you can not stand on the soil in front of it. A person standing in front of it will be on the street. The postal service accesses it from inside their vehicle on the street, which is where I am in my vehicle when I retrieve the mail. So anyone standing or driving on the ground around it would be trespassing on my property, and they get holes in their feet or tires. If you want to reduce chances of being identified as the source of the caltrops, chain them together so they all follow the car Jan 23, 2016 at 2:55
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    I'm afraid wet sand might act similar to concrete, which I'm trying to avoid.
    – Tester101
    Jan 23, 2016 at 3:07
  • the sand trick is what stret signs use in my area. Instead of wood, they use two different diameters of perforated square tubing, like this. images.lowes.com/product/converted/040395/040395552111lg.jpg The larger one goes into the sand, sticking out about 4 inches. I have to imagine they cover it in tape so it doesn't flood with sand internally. Then they stick the sign's post inside it and secure it with one bolt. Drunks can mow the thing down several times an hour and the sign replacement crews can keep right on up with a cordless drill. Jan 23, 2016 at 3:21

What about hinging the 4x4 post at ground level with a door-frame hinge, and something like an old trampoline spring to hold it upright, apart from the nuisance car?


Personally, I would just dig a hole and place it in it. Thats the easiest fix. Putting in concrete will not prevent a car from plowing into it and removing the 4x4 from the ground. It will, though, cause you to have to remove not only the pole, but the concrete you poured. I would put reflective tape on the pole to help drivers see it better and maybe move it a little further away from the road.

  • I can't move it, or the mailman won't deliver my mail. The box has to be 6-8" from the road, and I'm already at the maximum 8".
    – Tester101
    Jun 23, 2014 at 15:37
  • Also, I'm trying to avoid digging a hole every time somebody plows through my mailbox. So I'd like to have the in ground portion be undamaged in the case of a car hitting the mailbox.
    – Tester101
    Jun 23, 2014 at 16:05
  • @Tester101 - Unfortunately I cannot show you any photos. He designed and built it back in the 60's in another time and place. I'm sure it is long gone from its spot.
    – Michael Karas
    Jun 24, 2014 at 3:15

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