This question was answered fairly clearly in the information on the DesJamaan website. Fresh mushroom's probably couln't last the week plus it would take to make the trans-Atlantic flight from Europe, they would start to go bad at least, and dried mushroom's are illegal in the Netherlands. The US is very much on the embargo list, where no-one can legally ship grown, ready-to-eat mushrooms here. The problem point isn't that it's being sent to a PO box, it's that it is being sent to the US at all.
Up until now, your only choice has been to buy a grow-kit, which is not illegal, because at the time of import there is no active ingrediant psychodelic's included, they grow once it is in the privacy of your own home. But I have heard rumors that even this little loophole is being cracked down on, and considering I ordered a grow kit on the 3rd of March and it hasn't shipped yet, I believe that something is going one where trouble is arising.
As for peyote, If you can provide documentation, that you are a legal member of the Native American Church, then you can import all the peyote that you want. As that is most likely not the case (otherwise you would be doing it already).
Hope that helps, I was really looking for a way to get a nice little bit of mushroom's myself without buying by the hit, but so far nothig yet.
Good Luck
