> A downloaded mail can be edited, unless it's signed with PGP.
What is your threat model? Obviously, it does not include google (and by extension, the state actors that can compel it to do things). But what does it include?
Yes Google and NSA could do such things, and I wouldn't be surprised if Russia could do this as well. But for the ordinary man this won't happen, being a personal target for the big agencies.
When you're in court having having a dispute with a customer or your boss, you can't dispute Gmail timestamps etc. That's all I'm saying.
If I've received an email and keep it in the webmail, I cannot change that. A downloaded mail can be edited, unless it's signed with PGP. I can change content, headers, dates. An email in Gmail webmail cannot be changed by me. And while Google can do that, and maybe an excellent hacker can do that, the chance that you're the victim of that as an average Joe is very small.