Here in Oz, Australia Post has used Honda bikes for postal deliveries for a great many years, models like the CT110, NBC110 and the C110x.
These things have proved to be nearly indestructible
Whilst they are no powerhouse, they are economical, reliable and easy to ride slowly with their centrifugal clutch making the perfect in the role of postal delivery.
Decommissioned postie bikes are also popular runabouts on farms for the same reasons, as they are easy to rode one handed, you can put a small tank of herbicide on the back and a hand held spay wand, makes them ideal for spot weeding duties.
In fact, Honda have just recently released a new version here the CT125. If I was still on the farm I'd have one......beats the shit outta walking up the bloody hills which were seriously steep bastards!
"Keep calm, relax, focus on the problem & PULL THE BLOODY TRIGGER"