Per user encrypted mailbox, addressbook and calendar and like posteo

[svargh]

Summary

If user forgets password, then mails should not be recoverable by the admin.

Motivation

I am on posteo, but would like this feature for my own domains too. User can enable it, optionally.

In case hacker or bad government read all files from the running server, then the stolen valuable customer contact list &calendars and mails are still encrypted. There is a chance those guys can still extract keys from RAM, but still some barrier than having no barrier.

Additional context

No response