1. There is no form of encryption. This alone makes it obsolete garbage. Absolute shit useless garbage. Absolutely no, single fucking one should be able to read a message you send except the recipient period. This is already solved plainly for websites.
2. There should be a method for modifying emails you've already sent. It's fine that they obviously will be able to see past revisions. But not being able to edit at all is a complete deal breaker. Emailing is complete garbage because of this.
Reunto 0 points 4 hours ago
All encryption can be broken, some encryption is just harder to break than others.
The thing you have to ask is whether email has the appropriate amount of encryption for what it is used for.