You can either strip it and start over OR prime again with zinsser's BIN. Then paint with a quality paint. BIN is shellac-based and may encapsulate the odor. Beware - the BIN may smell worse for a few days.
Not sure why the door would smell. The paint would have cured by now. Did you use exterior paint on the inside side of the door? What brand(s) of primer and paint did you use?
Was the paint fresh, or had it been sitting around (leftover) from a previous job?