In California over half of ballots are sent in by regular, old fashioned, snail mail via the USPS. I have no handshake saying my ballot was received, no proof

In California over half of ballots are sent in by regular, old fashioned, snail mail via the USPS. I have no handshake saying my ballot was received, no proof that someone at USPS or with easy access to USPS shipping infrastructure (e.g. the mail trucks that don't get locked when the mail man goes out) doesn't swap in a different ballot, or any assurances that again someone isn't correlating my name and address with the ballot I mailed in. All these problems are mostly solved just by using something like HTTPS. Now the biggest problem is how secure people perceive the voting process to be. And since most people don't really understand how these things works there will be huge room for conspiracy theories to arise about vote hacking. This in turns undermines the democratic system. I've talked to many people who actually feel more secure sending in their credit card details over the POTS or by mail, not understanding that these systems are even less secure, even after explaining to them the vulnerabilities.