nevial

I'm not saying it necessarily is a good name but simplex is just a Latin word that's used in many contexts. I for one would have never thought of Herpes here

There is encryption at rest (storage encryption), transport encryption and end-to-end encryption. E.g. Posteo has transport encryption and optional storage encryption. With activated storage encryption, Posteo cannot read your mail because the encryption key on their server is only usable with your password (which they do not store). Proton Bridge adds end-to-end encryption to Protonmail

I'm curious what you mean by that. What exactly do you miss for these providers? (e.g. for posteo and mailbox.org, as those are the ones I am using)