Surprisingly a Coconut can be mailed with nothing more than affixing the proper postage. I very nearly purchased a Soviet motorcycle (with sidecar!) in Cambodia. There was plenty of room on our transportation back and the chain of command surprisingly didn’t seem to have a problem with it. It seemed too convenient somehow, though, and I’m not sure at all it would have been allowed back to CONUS from Hawaii. Possibly in “Household Goods” but that’s a bit of a stretch.
Some post offices would reportedly refuse to accept some items like bricks and bowling balls One thing that people used to do was to sneak up to the mail truck while the postman was delivering mail and leaving the object in the truck so that the mailman didn’t have a chance to refuse it.
Yeah, Ted Kaczynski pretty much ruined hassle-free mailing of parcels in much the same manner that “DB Cooper” ruined commercial air travel.
My Uncle Joe spent much of his time at a very remote Army weather station in Greenland during World War II. His transportation in the states was an old Harley motorcycle. Shortly after the war before he finally settled down in my community, he was visiting and had to order a new engine from Harley Davidson for his motorcycle. The engine was delivered by the US Mail.
My sister’s husband did two or three tours to Vietnam as a rescue helicopter pilot on CV-14, the USS Ticonderoga He said that after they left Yankee Station, they would first go to Japan where most of the pilots would buy Japanese sports motorcycles and that from Japan back to San Diego, the hangar deck would have all those motorcycles parked in it.
I don’t remember if it was mentioned earlier, but when you buy baby chicks, the preferred delivery is by mail. The post office calls you early in the morning when they arrive and you go pick them up then. If there is a big delay getting them to the post office, though, a great many will die.
Several years ago, my younger brother bought a hundred pheasant chicks so that he could turn them loose out in the fields when they were ready. Apparently, the box containing them was left out on a hot runway for several hours. Only about ten of them survived.
He was pretty disgusted and gave the survivors to the high school aged son of some friends in town and he put them in with his chickens that he had for his high school ag class. The chickens kill every one of the remaining pheasant chicks.
Someone should try to mail an Anvil. Putting it in a box would be counterproductive. They might want it on a pallet I suppose. “How to Piss off your Letter Carrier”.
I remember my older brother discovered a US Government printing office program in the 1970s that was out of Pueblo, Colo. iirc. You could send away for all this free swag from Uncle Sugar, Posters, he ordered a bunch of those, they are shipped in those long cardboard mailing tubes and are a pain in the ass, and all sorts of stuff. He was really big into that sort of thing, and I think he really did piss off the mailman. LOL
If you use a Priority Mail flat rate small box, you can mail literally anything that can fit in the box for the same price. It’s 5.5"x8.75"x1.75", with a maximum weight of 70 pounds, which should let you fill the box with the densest things on the planet and not go over the weight limit.
Someone must have looked up the density of osmium when they set the weight limit.
Very possible. When I ran the numbers, a box that sized filled with osmium would weigh 68.8 lb.
That’s the most interesting thing I’ve heard all day. I agree, it is literally (really literally, not figuratively literally) impossible to exceed the weight limit with those dimensions with normal matter found on Earth.
And that is indeed with osmium, the densest naturally occurring metal found on Earth. Of course, osmium also costs about $60/gram, so it would cost over $80K.
Pure gold would weigh less (58.8 lb), but would cost more (over $200K).
And lead would weigh just 34.5 lb (and would only cost about $30).
Maybe someone tried that or whatever in which case the postman would just throw it in the garbage. What a stupid prank.
If they did, why wouldn’t they just brag about “No weight limit!”
You used to be able to order bees through the mail. Dad ordered two pounds. He discovered that when two pounds of bees come into a suburban post office on a Sunday, the Post Master will drive it personally to the house.
They were nice and fresh.
When prepaid envelopes came with donation requests from politicians that my uncle didn’t like, he claimed to have attached the prepaid stamp to bricks. Not sure if that was actually possible.
You never know if someone is going show up with some neutronium they are trying to ship. 
You can hear them peeping in the little containers. It’s one of those things they can’t shove off to the side when a 3 day weekend is coming up. Ever notice Omaha Steaks doesn’t use the Post Office? Hm.
I think you still can. At least, there are mail-order companies that sell beneficial insects. Though the last time I had occasion to do business with such a company, I was in Bozeman, MT, and discovered that the nation’s largest such business was right across town, so it was easier to just go out there to pick up my ladybugs myself.
I was in high school when Dad ordered them, so that would be the early seventies. It’s been awhile, so I wasn’t going to assume.
Would it have been legal for a postman to throw away strange items that had the proper postage and addresses?
I’m not sure how this situation evolved over the years, but Kaczynski and similar nutbars and bombings, changed things dramatically. Parcels weighing more than a certain amount cannot simply be dropped into a collection box, pre-paid printed labels are OK. Or presented at a Post Office to a clerk. They must have a return address, they want to be able to tie a parcel to an address or individual. “Anonymous” mail is kind of a no-go. Leaking boxes, with only stamps, no return address, that sort of stuff gets their attention and do not get in the delivery stream.
Watching the PGA BMW Championship, I just learned that the Gateway Arch is 630 feet high and also 630 feet wide at its base. Had to confirm, as it certainly looks taller than it is wide. I think sort of an optical illusion since you measure the base from their edges.