Preheat your oven to 350°F (175°C).
In a mixing bowl, whisk together flour, sugar, baking powder, and salt.
In another bowl, combine melted butter, eggs, milk, and lemon zest.
Pour the wet ingredients into the dry ingredients and mix until just combined.
Gently fold in the blueberries.
Pour the batter into a greased loaf pan.
Bake for 60 minutes or until a toothpick inserted into the center comes out clean.
Let the bread cool in the pan for 10 minutes, then transfer to a wire rack to cool completely.