No voting system is inherently perfect, and there are risks involved with every option. Paper ballots have been scarred by hanging chad debacles, ballots stored in trunks, and ballots not picked up in mail-in ballot drop off locations. Email and fax as ballot return methods are inherently insecure, and easily compromised. Voting in person may be a more secure method as well, but it can lead to disenfranchisement of voters which undermines the overall integrity of free and fair elections.
Electronic ballot return voting, too, has its risks: nefarious state actors or individuals could try to hack the voting system, and employees of the industry partners may seek to disrupt the election results. The existence of these risks is why the National Cybersecurity Center is working hard to develop standards across the electronic ballot return voting industry for internal and external security.