As a side issue; At the turn of the last century during the rise of the postal service and the popularity of sending Christmas cards, postman wore red uniforms and were nicknamed 'Robins'. Early cards often depicted postmen going about their happy way delivering the Christmas mail. Obviously, pictures of postmen offered limited scope and appeal, so robins were used instead. The robins that you see on cards today are symbols of the postmen (and women). They are quite often pictured sitting on top of postboxes.