I would also go the other way, you have something you want to be sent to somebody via paper, but it's only printed at the last mile in the delivery vehicle. A

I would also go the other way, you have something you want to be sent to somebody via paper, but it's only printed at the last mile in the delivery vehicle. A birthday card for example doesn't need to be sent across the country or across the world, it only needs to become physical as close to your door as possible. Maybe this could be a security measure too, you have a document that can only be printed by a secured machine and is only produced at the last mile based on current position. It would reduce the risk of the mail being intercepted or mis-delivered.