RSBM. It's pretty common for drugs to be mailed by USPS. All packages require a warrant to be opened, compared to private carriers like UPS/Fedex. Most people aren't sending one huge package, but multiple smaller ones when it comes to flowers (buds). When it comes to concentrates (oil, shatter, hash), they can send exponentially more due to the size/weight ratio.
I've met some people who travel for legitimate sales jobs, and they mail "care packages" addressed to themselves at the hotels they will be visiting. As long as everything is packed securely and sealed with a quality vacuum sealer, detection is unlikely.
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