It is coming in where the bottom of the sidelight meets the horizontal brown weather strip door bottom. you could try clearing as much rust as you can and caulking with a heavy duty clear caulk along the top of the brown door bottom and up onto the door some.
Last edited by hand drive; 10-20-2012 at 11:37 AM.
Poorly flashed and installed door and poor or no no proper flashing for the 3'-4' canopy over the door. Very common with builders that just use a carpenter to install a door. Many better builders hire a certified window/door subcontractor (mainly for insurance and liability problems from mold and moisture damage in the wall).