My friend was extra careful and sent it to a PO box kind thing, with a fake name and throwaway email just in case. But he thinks that is overly paranoid: if the letter was intercepted (highly unlikely), there would be no legal consequences because there is no link between him and the purchase (therefore strictly speaking all that happened was that someone mailed him illegal drugs without his knowledge ;)).
It's a bad idea to send darkweb packages to a PO box, as the USPS will require a lower threshold of evidence to search the package. As it is they can't inspect your mail without a warrant, which is exceedingly rare for them to procure for a random package. Having it shipped to your home, although maybe somewhat nerve-wracking, is the simplest and most secure option in the United States (for now).
This is what my friends in the bodybuilding world have come to accept.
Yes packages get intercepted. But it isn’t the legal liability of an addressee for what is in some box that SOMEONE put in the mail. Otherwise it would be an amazing blackmail (nigh literally) tool to target any enemy.
Every jurisdiction has its own rules but in broad strokes: receiving a package containing drugs isn’t illegal, otherwise, anyone could send their enemy drugs.
To safely receive drugs through the mail, you do not do anything clever (like mailing them to an empty house) instead you behave in a way that gives you plausible deniability. And you do not do anything that would lead police to think you’re distributing.
Order small, personal use quantities to your name and your address and leave the package on your counter for a couple of days after it arrives. If the police show up, say you didn’t recognise the package and left it on the counter until you had time to return it to the post office.
Where you’re ordering from and to matters too. Ordering from the Netherlands into Australia almost guarantees the drugs will be found because all international mail is processed by Australia’s postal service and the Netherlands is an obvious source country. Order nationally to avoid processing.
Ultimately, it’s just like buying drugs on the street: be a nobody buying for personal use.
The biggest risk is that inevitably the seller will eventually get busted and your address will be in the seller’s records. If you’ve bought large quantities, the police will see you as a dealer and try to catch you in a sting. The best sellers do not keep records for this reason, but it’s something you won’t know until they get caught. If you buy personal use quantities, the police aren’t going to waste time on you, even if they have records of your orders.