Mix together the rum, maple syrup, ground ginger, salt, pepper and ground cloves in a large re-sealable plastic bag.
Add the salmon and remove as much of the air as you can in the bag and seal; marinate refrigerated for 4 hours.
Remove the fish from the marinade and set it aside.
Pour the marinade in a sauce pan, add the butter and bring to a boil over medium-high heat; continue to boil until thickened; remove from heat and set aside.
Cut a piece of foil big enough to hold the fish with a couple of inches overlapping all around the fish; coat it with non-stick spray and place the fillet on top of foil, flesh side down.
Place on a preheated medium-high grill over direct heat and cook for 3 to 4 minutes, until you have grill marks; carefully turn it over and continue to cook brushing it with all the reduced glaze until it is cooked through. The cook time will depend on the thickness of the fish, it will flake easily when poked with a fork.