Preheat your pellet grill to 180°F for low and slow smoking.
Pat the salmon dry with paper towels and place it skin-side down on a baking sheet lined with foil.
In a small bowl, mix Dijon mustard, maple syrup (or honey), olive oil, garlic powder, onion powder, paprika, salt, and pepper.
Brush the glaze generously over the top and sides of the salmon.
Place the salmon on the grill and smoke uncovered for about 2 hours, or until the internal temperature reaches 145°F.
Carefully remove the salmon from the grill and let it rest for 5 minutes before serving.
Serve with fresh lemon wedges and your favorite side dishes.