Preheat oven to 350 degrees. Grease and flour a 9x5-inch loaf pan.
In a large bowl, combine flour, baking powder and salt; set aside.
In a medium bowl, beat the eggs, sugar, and oil together. Add buttermilk, lemon zest, and lemon juice, beat until well combined. Add the wet ingredients to the dry ingredients, beat until just combined. (Do not over mix) Fold in zucchini, stir until evenly distributed.
Pour the batter into the prepared loaf pan. Bake for 40-45 minutes or until a tooth pick inserted into the middle comes out clean. Cool in the pan for 5-10 minutes, then remove to a wire rack to cool completely.
LEMON GLAZE: In a small bowl, beat the confectioners' sugar, lemon juice, and milk until well blended. Spoon the glaze over the cooled bread. Allow the glaze to set, then slice and serve.