Citizenship and postal address are irrelevant. If you break the law in another country and there is an extradition treaty then you will face the consequences.

That's not how laws work. Laws are limited in territorial applicability only to the extent that the sovereign adopting them so limit them, and basically no government would fail to hold foreign coconspirators in a crime occuring within their domestic jurisdiction immune to prosecution (some might not have the practical means to bring such an actor to justice, and some might not choose to apply them in most cases as a matter of policy priorities, but that's a different issue.)

Aiding and abetting.