I’ve been ordering cannabis on the darkweb for more than a couple years now. It ships US to US via USPS (to a state where cannabis is currently illegal), price is half of what I could get locally, and the selection is endless. Bliss.
I’m happy with the security of the markets and I think the digital trail is pretty tough to follow. When is USPS going to get better package scanners to detect drugs? With the state of machine learning I don’t think it’d be that difficult. Maybe USPS doesn’t care? Would they notify LE?

The first is the cost of these machines to the company.
The second would be adding time to overall time scale of delivering the mail, something the mail companies do not have. Also, more man power to take the packs out of circulation, screen them, notify relevant authorities etc.
I can't see it happening at the will of the mail services, only when the time come's that the feds lean on them to play a bigger part in detection. I'm sure the pressuring is well and truely on, and has been for a few years now. There's probably a back an forth going on atm with the higher ups on both side's, trying to implement and not implement better screening machines.
I guess time will tell. I guess as you mention, with the advent of machine learning evolving exponentially, they're probably waiting for a time when they can implement it, with using as little man power as possible.
Manufactureres in China are standing by waiting for Western customers to start ordering lead-lined bags, wholesale. They already exist.
Edit: I did try to be mindful of the rules in writing this post. I've tried to keep it both vague, while still being of use in promoting lateral thinking as goes packaging, and not running a conveyor belt operation that will leave you far more open to LE enumeration, or indeed with the volume of trade rising, eventual criminal enumeration of your chosen enterprise, scanning physically or pattern matching electronically, as LE will eventually have to do. Particularly in view of first class domestic being protected mail, I can't see judges ruling to abolish the protection in law it currently receives, especially the way they ruled over the FBI's multi-thousand Tor user hack a while back.
In a forest
Personally I would hide pills within pills
Create a phony bottle of placebo pills (herbal remedy) all with white casing, and then the real ones can be in red casing :)
really until there is a way to almost 100% of the time determine something is a drug or not automatically through a machine when being shipped, i dont think we will have any major problems concerning usps or the mail. like others said though, other items are shipped through the mail that are perfectly legal that may resemble drugs when scanned or looked at by computers. Such as herbs, spices, medical supplies etc.
Shit was bulging reaking, made it, no questions asked.
Shit back then lol.
I have been ordering drugs off the dark interwebs for around 5 years now including MDMA from the NL and coke from a vendor I'm pretty sure got busted because about a year ago I got a call from the DEA about case # blah blah blah that I never returned and never got a call bak... and I'm not really trippin on it.