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A ‘drop box’ is an item of Royal Mail street furniture. It is a receptacle where the postman can securely store part of his morning round, at a convenient location. Sometimes, the Royal Mail van may drop off the postman with his bike and morning deliveries, saving him carrying a heavier load or frequent returns to the sorting office.
Originally drop boxes were attached to pillar boxes and, therefore, painted red to match. Nowadays, they are separate free-standing boxes – usually close to a postbox – generally painted grey but sometimes red.