Mail-in voting should be restricted to deployed military and maybe those in the hospital too sick to go vote, but that’s about it.
Set up poling places on military bases, let them vote for president. Beyond that they are not residents of a state. Do the same thing with embassy staff.
Change the tax laws so that expat with no US income and who live 330 day a year outside the US pay no income tax but lose the right to vote while living overseas. (Note: I lived overseas for 24 years)
Then:
1. Abolish absentee voting, but have the polls open 24 hours.
2. Purge voter rolls every 5 years.
3. All ballots must be delivered within two hours after the polls close; beyond that time, no more will be accepted. To ensure the safety and arrival of ballot boxes they must be escorted by a law enforcement officer.
4. Once counting starts, it cannot stop.
5. There must be a live video of the counting room.
6. The precent tally of voted and spoiled ballots supplied by poll workers must match the totals in the sealed box. O otherwise the box contents are void.
6. No partial totals can be released.
I remember when the military didn’t get their ballots in time to mail back.