Start by taking a clean, dry towel and clean both sides of the door. Next, try to get into all the crevices to remove the pollen and dust. You can also do this with a vacuum for easier access.
To deep clean a metal door, you can also use dish soap and a bucket of water. Start by combining about a gallon of hot water and then drop in about 1 tbsp of your preferred dish soap. Then dip a clean try towel into the mixture and begin scrubbing from top to bottom.
Make sure the water isn’t too hot, as this can cause the paint to chip. Use a microfiber towel to avoid any scratches on the door.
Once you’ve cleaned all of the dirt and grime, take a clean damp cloth and remove the excess soap. And once your door has no traces of soap, take a dry cloth and dry off the door.