@phenomlab Yes. As you pointed out, I was talking about OpenPGP Additionally, Proton Mail is one of the services I use.
After Robinhood and T-mobile data breaches in the US, unfortunately, my “good” email addresses are out there in the dark web. So, I was researching how I can re-structure my email inboxes, and several months ago I encountered with Simple Login app. It is an open-source project too. Have you heard of them? It is an email relay service with alias either in random or custom domains. And you can create unlimited alias and disable them very easily after they are breached.
I actually bought the premium version 1 month ago and last week Simple Login company is bought by Proton Mail, so I believe this application will be around for a much longer time. It natively supports OpenPGP just like Proton Mail. I have already added my custom domains there for email.
I was thinking maybe I can add these public PGP keys in Simple Login and open the emails with private PGP keys on my computer (I guess with Thunderbird? since it supports OpenPGP natively). So, emails are never read by the email servers.
I wonder your opinion about this strategy. This will require to trust Simple Login servers, but I trust them more than I trust Gmail, Outlook, or GMX Servers