I'd be surprised if there were no door drains but I didn't look at either of mine before they went to PnP so I can't say for sure. Every car I've ever worked with had a drain or at least a method to vent the inside of the doors so that there was some air flow so any water that got in there could evaporate. 70s/80s GM cars, for example, had a vent in the door part of the door jambs that allowed air to escape when closing the doors and also allowed air to vent in and out. Seems like they also had some drain slots though I don't remember that for sure (it's been a while!).

Dan