Even if they did, won’t they get a lot of false positives because of a large amount of it being sprayed hemp buds that are legal as hemp? Also, I know a lot of dispensaries get their stock like vape pens and such delivered this way already. How does that all work?
For USPS they have a list of verified hemp vendors, they tried a couple years ago to open packages suspected of marijuana without a warrant. The outcome was it doesn’t matter if they suspect it, you still have to get a warrant. So now if a vendor is a certified hemp vendor they can’t touch it. Now UPS and FedEx are private companies so they can do pretty much whatever they want, that’s why almost all hemp shipments go through USPS. I’m paraphrasing a lot but that’s the gist of it. USPS is currently and has been the largest drug dealer in the country, even with omitting hemp because with the volume they process you could never catch them all and every other drug doesn’t have a pungent smell like weed.
A friend of mine used to ship pounds at a time through FedEx. He would ship about 20 packages every fall, half of them made it to their destination, but he and the recipients were never contacted about it. His thinking was that if someone at FedEx noticed, they would just keep it, while someone at USPS would probably get the wheels turning for prosecution.