Seeds are illegal in the US
With exception being legal States, but even in a legal State technically not allowed to use the Postal Service.
Odd I always heard seeds were legal and were considered a adult novelty. Just germinating them wasn't legal? Not that I'm worried it's legal here but it would be interesting to know
One of those how they try to work the system or tie things up with legal mumbo jumbo talk, not likely they going to prosecute a company that's in a different country for seeds (be different if a Cannabis product/flowers), so they just confiscate them as "contraband" if they find them at Customs.