Absentee voting has been going on for decades and is used by service men and women. My first Presidential vote was absentee when I was in the Army. Some states already have mail in ballots, some are for anyone who wishes to others restrict to only if you will not be in town on election day. You have to first have been at the driver's license station with your birth certificate and proof of address. One or two official type pieces of mail from governmental agencies or similar. Then you have to request a ballot, make an application, confirming the information from your driver's license. Then you get mailed the ballot to the verified address on your license and a return envelope. You have to put your name and sign on the envelope, the signature should match what is on file. That kind of mail in, IMO, is fine. That is not just throwing out millions of ballots randomly.

Even in cases of voting in person usually I don't even have to show ID, just say my name . Then they cross you off the list. Usually somene who is not on the list at all can still cast a provisional ballot. The electronic voting machine changing your vote to the other guy and you have to hit it again and hope it sticks, hanging chads, other people handle the ballots, boxes of ballots appear out of the trunk of a car. All votes can be compromised or have a risk of fraud. I am for a national voter ID for Federal elections.