The post office has long delivered through rain, sleet and snow.Now add Sundays.In a move indicative of the changing retail landscape, McMinnville Post Office will now be delivering Amazon packages on Sundays. The new service takes effect this Sunday.“We were selected as one of the sites where this will start happening,” said McMinnville postmaster Brent Nunley. “The goal is to get it to you faster.”Nunley just learned of the agreement Wednesday and said delivery plans are still being formulated.