Delta Chat is an in-between project: often ignored as a messenger by e-mail companies/experts and then ignored by messenger companies/experts because of its use and interoperability with e-mail. As Heinz von Foerster once said: "If you are doing something genuinely new then don't ask the experts. If you do something that has already been done, then, by all means, ask the experts." FWIW many experts have verified Delta Chat's security mechanics https://delta.chat/en/help#security-audits :)