Postman Pat
Postman Pat was a character whom was recalled by Starkey when he met a real postman named Patrick. (TV: The Last Oak Tree)
Behind the scenes
In non-valid sources
Postman Pat was with his cat Jess, delivering packages in Greendale, when a boy arrived. Pat asked the boy to deliver a package to Bagpuss & Co., to which he obliged, leading Pat to remark that he was a "nice young man". (TV: Future Generations)
Other matters
Postman Pat is the titular character from the series Postman Pat.
Carole Boyd provided the voices for the children and female characters from 1991 right up until the conclusion of the franchise in 2017.
The Postman Pat movie released in 2014 featured Jim Broadbent and David Tennant amoung its voice cast.