Royal Mail agreed it would collect letters from boxes in private houses or public buildings (generally for an annual fee) in 1878. The boxes were the property of the landowner but Royal Mail was keen to ensure the integrity of the mail and so insisted the box meet certain requirements. This wood and metal private posting box with pull-down flap has some decorative carving and a small glass window to show how full it is, and is part of a collection amassed by post box enthusiast Ian Wilkinson.
The increase in the amount of mail and addresses means that collection boxes like these are no longer used today.