According to the Public Religion Research Institute, a majority (57 percent) of white evangelicals and a plurality of black Protestants (43 percent) do not think that Mormons are Christians. Majorities and pluralities of all other groups (PRRI doesn’t break them out) are prepared to accept Mormons’ own self-identification as Christians. I assume this includes Jews, and for good reason.
Mormons believe in the divinity of Christ, and believe that Jesus’s Atonement is necessary for salvation. These doctrines put them into the Christian camp, so far as Jews are concerned. Just like, say, Oneness Pentecostals, who also fall outside the bounds of traditional Trinitarianism but who yield to no one in their estimate of Christ’s divinity. By contrast, Unitarians, by not accepting that divinity, operate for Jews in the non-Christian world, so much so that, over the years, many Jews have felt comfortable joining Unitarian congregations. Sort of like Buddhism.