Water accumulates on the bottom of my Sub zero and rolls down the front, causing this area to rust and the freezer door to ice up. The inside drain is clear.
If this is a bottom mount freezer model then most likely the problem is a bad temperature insulation between the freezer and the refrigerator. It is not repairable. It is pretty hard to remotely diagnose a such problem. I would recommend to call a certified refrigeration tech to do it for you.
Gene.