A: London, England, United Kingdom
On April 1, 1680 English merchant William Dockwra, with partner Robert Murry, founded the first Penny Post in London, for mail delivery within the city of London and its suburbs to a distance of 10 miles. The service worked on the basis that the one penny postage was paid when the letter was accepted. This was in contrast to alternative private courier systems which were paid upon delivery of mail by the recipient. Under that system mail was often refused.
Dockwra's London Penny Post was the first postal system to use hand-stamps to postmark the mail to indicate the place and time of mailing and that the postage was prepaid, but handstamps were not used in the first months of the post's existence. The earliest knnown Penny Post postmark is dated December 13, 1680.