In a small bowl combine mayonnaise, Dijon, honey, soy sauce and lemon juice. Remove about 6 tablespoons of the honey mustard sauce and set it aside.
Mix the chicken breasts with the remaining honey mustard sauce and marinate for up to 4 hours in the refrigerator.
Lightly grease the grates of an outdoor grill. Heat the grill to medium-high heat. Add chicken to the grill and cook for 6-7 minutes per side or until fully cooked (the internal temperature has reached 165 degrees F.).
Drizzle reserved sauce over the cooked chicken breasts.