It is very clear in the Doctrine and Covenants 76:30–37, that the only persons who will be completely overcome by this dreadful fate are the sons of perdition, who go with the devil and his angels into ‘outer darkness.’ All the rest of mankind, even the wicked, will receive some measure of salvation after they suffer the wrath of God.
However, they will of necessity be brought to repentance and acceptance of the gospel of Jesus Christ as far as it will apply to them. They will not be given the ordinances which do not pertain in their kingdoms. From the reading of other passages we discover that there will be great multitudes embracing the vast majority of mankind, who will never be privileged to come back to dwell in the presence of the Father and the Son. These receive banishment from their presence, but not entirely do they get beyond the divine benediction… .
All those who are permanently subject to the second death are those who have had the testimony of the Holy Ghost and who have known the truth and then have rejected it and put Christ to open shame.
(Joseph Fielding Smith, Answers to Gospel Questions, 1:76, 78)