Diagnosis
Yeah, this one's a front-loader classic. Moisture gets trapped in the folds of the gasket, and detergent residue feeds mold growth.
How to Fix It
Wipe the entire gasket dry with a microfiber cloth after every load. Leave the door and detergent drawer slightly open between uses. Monthly, run a cleaning cycle on the hottest setting with a washing machine cleaner or two cups of white vinegar.
If That Didn't Work
For stubborn mold, mix a paste of baking soda and water, scrub the gasket gently, then rinse. You can also remove the gasket for a deep clean, but it's tricky—consult the service manual for your model.
Heads Up
Using more detergent than recommended makes this worse. High-efficiency washers need only a tablespoon or two; excess soap builds up and stinks.