The rubber seal at the front of the machine has

Front loaders are known for building up mold and the smell.
It’s caused by using liquid detergent which is made from animal fat. Use powder. And use the minimum amount.
It’s caused by using fabric softener. Dilute it 50/50 with water.
It’s caused by the water remaining in the tub between washes. Leave the door open to allow it to dry. .

try washing it with a mild viniger mix after bleaching to kill the mold, the viniger aids in killing the smell, it also retards the regrowth of mold, which is growing there due to the moisture retension of the seal.

Front-load washers are designed for high efficiency operation while using low energy. But unfortunately, there is a down side to this energy-saving washer model. Some consumers have experienced mold or unpleasant odors developing in their front-load washers. Once present, these issues can be quite difficult to resolve. With a little extra care, you may be able to prevent these issues from occurring.
What Causes Mold, Mildew or Unpleasant Odors?
Because of the low water level, wash residue such as grime, dirt and even skin flakes, along with water softeners and detergents do not always fully drain out of a front-loading washer. Using cold water for most loads can also add to the problem. Residue can build up in the rubber door gasket, soap/softener dispenser or other parts of the washer and over time, mold can begin to form or the washer can take on a smelly disposition.
Tips for Preventing Mold & Smelly Problems:
Always leave the door and dispenser unit slightly ajar after the laundry is done. Front-load washers and the detergent/softener dispenser drawer must dry out.
Never leave a wet washload in the washer overnight; remove it when the washing cycle is complete and leave the door open.
After a load is done, always rotate the drum with your hand to see and remove all items. Some could be sticking to top or sides of the washer drum.
Use softener sheets in the dryer instead of liquid softeners in the washer.
Liquid detergents may leave less residue than powdered formulas which may not dissolve properly.
Use less than the recommended detergent level for your load. Too much detergent can cause a residue build up. Experiment until you find a minimum measurement that delivers a clean wash. This is also a money saver.
Occasionally wash some loads such as whites, linen and towels in warm or hot water to help flush out wash residue.
Always clean your washer as per your product manual. High efficiency front-load models have a cleaning cycle and it's imperative that you periodically run this cycle as directed.
Check the gasket just inside the door opening and remove any visible debris. You can also wipe it to speed the drying process.
Always use HE detergents with high efficiency front-load washers. Specially marked HE laundry detergent is low sudsing and is recommended for these low-water washers.
If You Already Have a Front-Load Washer Mold/Smell Issue:
If your front-load washer is still under warranty, contact the manufacturer for repair
or replacement. You may need to take a firm stand with your dealer ormanufacturerto ensure they remedy this problem.
If your warranty period has expired, your first line of attack is to try and clean the
washer to remove any offending mold. Some consumers have had good results with products such as Affresh® which is designed to clean high-efficiency washers. However, some have had no success with such products.
If the gasket appears to contain mold, replacing it may solve the issue. There have
been legal class action cases regarding such issues and some may still currently be
before the courts. For this reason, it's difficult to get definitive answers from
manufacturers. Contact your Consumer Protection Branch to log a complaint.
Inquire if there are any legal proceedings for your particular brand of washer.
You may be able to participate in such a claim and receive a settlement.