An entryway system includes an elongated threshold assembly and a pair of plastic jamb boots attached to the ends of the threshold assembly. The jamb boots have flat level upper surfaces and a pair of jambs having square-cut bottoms are secured to the jamb boots and extend upwardly from the threshold assembly. A head jamb completes a door frame. The jamb boots are formed with integral drains that receive water from within the threshold cap channel of the threshold assembly and direct it away from the entryway. The plastic jamb boots prevent rotting and eliminate the need to mill the bottoms of jambs with haunches configured to fit the threshold assembly. Stops are provided in one embodiment at the bottoms of the weather strip kurfs to position the bottom ends of weather strips above the sill of the threshold to prevent weather strip wicking and consequent leakage in wind-blown rains.