▁Mail - F lo ▁Let ter ▁Process ing ▁System , ▁which ▁used ▁convey ors ▁to ▁speed ▁mail ▁processing . ▁ ▁However , ▁rapidly ▁increasing ▁mail ▁volume ▁and ▁postal ▁def ic its ▁prevent ed ▁the ▁Post ▁Office ▁from ▁completely ▁modern izing ▁and ▁mechan izing ▁all ▁of ▁its ▁many ▁post ▁offices . ▁ ▁To ▁improve ▁the ▁Post ▁Office ' s ▁image ▁with ▁the ▁public , ▁Summer field ▁began ▁a ▁prom ot ional ▁campaign ▁designed ▁to ▁show case ▁Post ▁Office ▁achiev ements . ▁ ▁On ▁October ▁ 7 , ▁ 1 9 5 4 , ▁Summer field ▁appeared ▁on ▁the ▁ABC ▁television ▁network ▁to ▁introduce ▁an ▁innov ative ▁anth ology ▁series , ▁The ▁Mail ▁Story , ▁subt itled ▁Handle ▁with ▁Care . ▁ ▁The ▁semi - document ary ▁and ▁dram atic ▁program ▁ended ▁its ▁run ▁on ▁December ▁ 3 0 , ▁ 1 9 5 4 . ▁ ▁On ▁July ▁ 4 , ▁ 1 9 5 5 , ▁in ▁order ▁to ▁highlight ▁its ▁new ▁image ▁as ▁a ▁modern ▁organization , ▁the ▁Post ▁Office ▁adopted ▁a ▁new ▁red , ▁white , ▁and ▁blue ▁color ▁scheme ▁for ▁all ▁Post ▁Office ▁collection ▁boxes , ▁tr uck s , ▁delivery ▁v ans , ▁and ▁equipment , ▁as ▁well ▁as ▁new ▁technology ▁and ▁procedures ▁for ▁mail ▁delivery . ▁ ▁As ▁part ▁of ▁that ▁effort , ▁Summer field ▁supported ▁experiments ▁with ▁ro cket - del iver ed ▁mail , ▁using ▁the ▁miss ile ▁mail ▁car rier . ▁ ▁The ▁first ▁and ▁only ▁flight ▁of ▁the ▁miss ile ▁mail ▁car rier ▁occurred