bookreader
I think that it’s pretty relevant to use Gmail with its soon 2 billion users as an example in order to describe e-mail reality.
But maybe we’re not talking about the same thing.
E-mail is a collective system; most of the time, it takes at least two people for an e-mail to be transmitted, a sender and a receiver.
With in-transit encryption, even when mandatory, it’s pretty difficult to ensure that the content of a given message will stay private and unaltered. At least, as far as I understand, that is the case with the hop-by-hop transport model used by e-mail.
What are you suggesting then? To control the whole route, each hop, and even the receiver infrastructure? In this case, we’re not talking about the collectiveness of e-mail…
Mandatory encryption has a cost. It is true that you could simply blindly use mandatory TLS, and accept that some e-mails will never be received. So, yes, from this perspective, e-mail would be more secure, but also more unreliable and totally impractical regarding deliverability.
But what’s the point then? It’s easy to be secure if you’re ready to accept many messages should be sent by other means than e-mail, and that you’ll never be aware of some messages meant to you.
The reality is that people, institutions, etc., who will send you e-mails, or ask you to send them, sometimes more or less pressingly, won’t set up their own mail server, according to your preferences, if it’s not already the case.
At this point, you’re describing something else, because e-mail is inextricable from its collective nature. It’s like saying snail mail is totally secure, as long as you choose your postman and control the sorting centre. At one point, you’ll have to trust intermediaries (e.g. MTAs).
E-mail is popular because most people do not have to dedicate themselves on the technical aspects; for most people, it just works.
Most people don’t manage their own mail server, and use opportunistic TLS for their daily correspondence, even on this forum; so what’s the conclusion? That most people have poor preferences, or that e-mail is not inherently secure?
And let’s not forget that there are other risks.
Sure, e-mail can be secure, up to a certain point, but acknowledging this is not the same as saying that e-mail being insecure is a mere belief. And by secure, I mean you should use PGP, most of the time.