Preheat oven to 350 degrees F (175 degrees C). Grease and flour 2 loaf pans.
Sift flour, baking soda, cinnamon, and salt together in a large bowl; make a well in the center.
Whisk eggs, butter, sugar, and vanilla extract together in a separate bowl. Fold mango, coconut, and walnuts into the egg mixture; pour resulting mixture into the well in the center of the flour and mix well. Pour batter into prepared loaf pans and let sit at room temperature for 20 minutes.
Bake in the preheated oven until a toothpick inserted into the center comes out clean, about 1 hour. Cool in the pans for 10 minutes before removing to cool completely on a wire rack.