Personally, I think he's flat wrong on this one.
For one thing, I expect that Private Joe isn't going to be sitting down at any old computer and emailing his scanned ballot back to his County Clerk. It's going to a specific office, which no doubt will be the same office we've been able to fax our ballots to for years. They'll fax it from there. The accountability he is so concerned with will likely be dealt with the same way as the faxes...the paper ballot is then mailed back to the state. The electronic transmission simply ensures that it arrives on time, which appears to be a big concern with Missouri's predicted delayed start on printing up the absentee ballots.
The end rant about vendors is confusing. There ain't no vendor. It's just secure email. We send lots of freaking things via email every day, over channels that we already have. Heck, the reference to "secure" may very well mean the secret net. If that system has problems with forged emails, then I don't give a damn about a squirrly election because we're fucked already from the security breaches.
And by the way...I quite agree about SERVE. It looked scary. But this doesn't.
Edit: Had more to say later, after the hubby and I had a chat and I remembered the other things I'd intended to include.