Royal Mail NZ

There are many wonderful post boxes in NZ and needing a new post box we invested in a 1950's replica of a UK post box which will be receiving a new coat of paint soon.
Amusingly While Beverley was gardening an elderly gentleman stopped when passing and asked "If I post a letting in there will it reach the UK"? 
B replied that it wouldn't.
Ten minutes later he returned and said "Excuse me but are you sure"?
He was assured that it would not.