They would have to pay NZ post to carry it the rest of the way. I guess they could invent another ticket for the sender to add to cover that, but with how vocal rural people are about whining about not wanting to pay for a service, I dont see it going down that well.

Really sucks for semi rural people that have a PO Box when they dont know what courier is going to be used to send things, they either pay the rural charge which probably isnt needed or else put their PO Box and have things not ship.