Mail delivery is a perfect application for an electric vehicle, since mail trucks don't go long distances and spend so much time idling.

I don't see drones replacing trucks entirely, but they could be an interesting way to augment a fleet of trucks. They would reduce the amount of cargo a truck would need to carry, meaning the trucks could be smaller and thus less expensive to run.

Maybe this wouldn't work everywhere, but in the right setting a self driving car would be perfect for mail delivery. All it'd have to do is follow the lines of the street and stop at mailboxes.

Like the soon to be departed Grumman LLV, the Renegade is small, affordable, relatively fuel efficient, and rugged. Jeep just needs to extend the wheelbase, take out the back seats, raise the roof, gloss over the fact that it isn't made in the US, and they'll have a great shot at being the next mail truck.