PGP/S-MIME encryption for any incoming mails

[thiekus]

I have been used Mox mail for my personal email so far and really easier than I though from my experience establishing another mail server stack. But the only I missing there is lacks storage encryption (at least for now). It can be good idea if you host your mail server at the server you cant fully control (e.g VPS/Cloud server) and you can still keep access with your private key elsewhere. It's bit different from #23 which is also good idea to not implements PGP/S-MIME in server side for outgoing mail.

AFAIK, some privacy mail service like ProtonMail also has same shortcomings like another S-MIME encrypted mail like lacks of full body search. It's also possible by using filter for postfix like this or like GPG Lacre does. But it's nice if Mox can handle this for usually unencrypted incoming mails or there's possible to implements by using filter hooks. Thank you!