A couple of months ago we posted a letter to England. The Kid had written a message for his English grandparents and we mailed it a couple of days before leaving for Europe to see who will get there first - us or the letter.
The letter did.
In fact, it got there in about 72 hours. We posted it Thursday morning and by Saturday evening (Sunday morning New Zealand time - we hadn't even left Invercargill yet) it was there.
I still can't get my head around that. The letter went from rural centre NZ (Invercargill) to rural England. Even if I travelled that distance as direct as possible (domestic flight from Invercargill to Christchurch, then international Christchurch to London with a layover somewhere in the middle, say, Singapore, then train from London to Salisbury and a car from Salisbury to the little village where The Kid's grandparents live) I would struggle to do that in less than 48 hours.
The letter did that - with all the sorting stations and transfer stations in between - in 72.