A mail coach is a stagecoach that is used to deliver mail. In Great Britain, Ireland, and Australia, they were built to a General Post Office-approved design operated by an independent contractor to carry long-distance mail for the Post Office. Mail was held in a box at the rear where the only Royal Mail employee, an armed guard, stood. Passengers were taken at a premium fare. There was seating for four passengers inside and more outside with the driver. The guard's seat could not be shared. This distribution system began in Britain in 1784. In Ireland the same service began in 1789, and in Australia it began in 1828.
The Edinburgh and London Royal Mail, 1838. The guard can be seen at the back. John Frederick Herring
North Country Mails at The Peacock, Islington 1821. James Pollard
The Royal Mails departure from the General Post Office, London by James Pollard, c.1830.
Royal Mail coach in the Science Museum London
A stagecoach is a four-wheeled public transport coach used to carry paying passengers and light packages on journeys long enough to need a change of horses. It is strongly sprung and generally drawn by four horses although some versions are drawn by six horses.
Preserved Concord stagecoach in Wells Fargo livery
Postcoach or diligence in Switzerland
Behind time, anonymous engraving of a stagecoach in England
Wells Fargo mud-coach