Millions of absentee and provisional ballots will never be counted. The reason is that states only count such ballots if they are more numerous than the votes between the top two vote-getters. For example, if Trump wins in Michigan by 13,000 votes, and there are 12,999 absentee ballots, it is not worth counting them since those votes could not change the result.
But wait, there’s more: 2/3 of absentee voters have historically voted Republican. So if the absentee ballots were counted Trump’s totals would likely see him having won the popular vote by hundreds of thousands, if not millions, of votes.