Cook it until you reach an IT of 140-145*
mixed 2 ml (1/2 teaspoon) of mayonnaise with 2 ml (1/2 teaspoon) dijon mustard and 2 ml (1/2 teaspoon) dried dill weed and spread over fillets on a small sheet of aluminum before smoking at 350 for 25 min in a pellet smoker.
For what it’s worth, I eat a lot of salmon living here in Alaska. The cook depends on the type of salmon. I generally like to keep the temperature around 230. The best way I use to tell when the salmon is done properly is that it flakes and when I stick a knife into the flesh it is warm but NOT hot. Salmon will dry out in a hurry and readily takes in smoke. I like to smoke it over alder for 45 mins low and slow and then wrap with rub, lemon juice, grated ginger and clarified butter in foil OR searing it quickly with the same ingredients on a cast iron skillet. Personal preference here, but I also do not cook with the skin on. I also primarily cook with Red (sockeye) or Silver (coho) salmon. I prefer to bake Kings, and if I have fresh pinks they smoke fine, but are softer than the others. Red salmon have an almost shellfish taste to them while Silvers are more mellow.