No Christian denomination that I am aware of considers Mormons to be Christians.
Of course they are Christians. Church of JESUS CHRIST of the Latter Day Saints. Mormons just believe in an additional holy Book, coming after the Bible. Much like muslims do. The koran is the next step, an expansion of Christian beliefs. Joseph Smith was just a prophet that followed Jesus, but Jesus was still the Son of God. muslims believe that big mo was a prophet that followed Jesus but Jesus wasn't the Son of God.
Denominational Christians rely on the Bible's closing paragraph that says that nothing would follow it. The Bible itself was the final word. Neither Mormons nor Muslims believe that so Christians have some basis to say that Mormons aren't "real" Christians. But the fundamental values of Mormonism and denominational Christianity are the same and come from the same Bible.