Using Award travel for trans Atlantic flight. Using UAL Explorer card to pay fees. Leg 1 -domestic UAL flight with overnight at DEN; Leg 2 to Canada with UAL flight , & Leg 3-with Star Alliance parnter on trans Atlantic. 1) Are there checked baggage fees? 2) Will checked bag be checked through to destination? Guidelines and info provided by UAL are 'confusing'. Any real world insight/experience will be appreciated.