Election Day is Tuesday, Nov. 3, but registered voters in Colorado will start receiving mail-in ballots after Oct 9. With national concern about the integrity of mail-in ballots, Colorado is getting national attention for its system. Colorado began statewide vote by mail in 2013, although some counties adopted mail ballots before that.

We know voters and potential voters will have questions about how voter registration works, how mail-in ballots work, how ballots are counted and more. The Colorad...