M&S, Morrisons or Waitrose Letterbox Flowers? For gorgeous and affordable letterbox flowers, take a look at the these flowers posted through the letterbox from top rated and highly popular online florists – Great alternatives to M&S, Waitrose or Morrisons letterbox flowers…  (FREE Next Day Flower Delivery) Charlotte £26.00 Goto Florist Laura £28.00 Goto Florist Gabriella £26.00 Goto Florist Oriana £25.00 Goto Florist Iris £26.00 Goto Florist Molly Mae £27.00 Goto Florist