Water and fabric threads usually get stuck inside the rubber folds around the door in front-load models. You must gently pull these folds open, wipe them with a damp cloth first, and then use a dry cloth. You can also remove the detergent tray, wash it with water, and scrub the hard soap stains in the corners with a soft brush.
People wrongly think that extra soap cleans clothes better. Excess detergent actually builds up inside the machine and causes bad odors. Next, you must turn off the power supply. Open the lint or pump filter at the bottom of the machine, remove trapped hair and paper bits, and fix it back. You can check the manual to find the filter location, as it changes for every model. You must dry the filter completely before putting it back.