Rust proofing door seams

Doors are designed to run water down the glass and some will go inside door. The problem is when the drains get clogged up, which they do fairly easy since the hole is small.
A heavy coat of epoxy down in there followed up with some good quality seam sealer. Be sure the seam sealer is level and wont keep the water from running to the drain. Do the whole bottom seam and up the sides a few inches. I wouldnt worry about going all the way up.