I'd buy this - fab idea

Events:

1) sat nav breaks - can't post anything for hours - just drives around!
2) Dog eats the mail
3) Dog its delivery person
4) Sorting office carousel breaks - rather like heathrow airport (LOL) resulting in lost parcels and failed deliveries!
5) Posty is giving a ticking of for trying to push a 2 inch parcel through a 1 inch letter box (personal experience the other day!).

Upgrades - railway network with postal trains and air freight to operate.