A reply disagreeing got deleted, but in case anyone else is wondering, you're trusting your ISP because SMTP's STARTTLS, the most standardized, widespread email

A reply disagreeing got deleted, but in case anyone else is wondering, you're trusting your ISP because SMTP's STARTTLS, the most standardized, widespread email "encryption", is basically worthless[1] if you're really paranoid. It's not required, so if you try to require it you're going to be unable to receive/deliver some email. It's negotiated over plaintext, so ISPs in between can just make the two servers think each other doesn't use it. I believe there's also some confusion in the standard, or at least widespread bad implementations, about how to verify the certificate, so an attacker can probably MITM the cert too. You can of course encrypt the mail yourself with GPG etc, but that would make self-hosting, the topic of this sub-thread, less relevant, and nobody but your fellow cryptonerds will do it. [1] https://blog.filippo.io/the-sad-state-of-smtp-encryption/ https://blog.filippo.io/the-sad-state-of-smtp-encryption/