Heat gas or charcoal grill. In small bowl, mix dill, mustard and honey. In small bowl, place 2 tablespoons mustard mixture; stir in mayonnaise until well blended. Refrigerate sauce until serving time. Reserve remaining mustard mixture for brushing on salmon.
Spray skin side of salmon with cooking spray. Place salmon, skin side down, on grill over medium heat. Spoon reserved mustard mixture onto salmon, spreading evenly. Cover grill; cook 10 to 15 minutes or until fish flakes easily with fork. Serve mayonnaise-mustard sauce mixture with salmon.