Because your front door is the mouth of your house and is the place where good energy flows in, a mirror is not advised there because it pushes away the good energy that is trying to enter.
Sometimes, a built-in mirror or even a mirrored closet door faces the front door and these are not easy to remove. If this is the case, you can paint a picture on the mirror with wash-off paint (if you are renting).
Another idea is to place something in front of the mirror. You can place a large, green plant, a piece of furniture, or even a large piece of decorative art to block the energy of the mirror from facing the front door.
Even if the mirror is not facing the front door right at the entrance, but is farther away and at the exact level of the front door, it will still have a minimizing effect of the positive energy trying to rush in – so don’t think because the mirror is not close, it isn’t a problem if it is facing the door.