If I was you I would take off the covers that allow access to the door hinge bolts from inside the car, once they're removed you should be able to see the drain pipes and check that the water is flowing freely out of the end of it. I doubt they're cracked though, if they were then the water would probably still drip into the sill where it should be going, it seems more like the problem is that the water is not flowing properly from the sill out of the jacking point. Could possibly be routed wrong but unlikely I would say. Might be worth also looking at the other side to see how that ones routed to check if it's the same and also make sure there's no problems occuring on that side before they get too bad