Running your own email server is not for the faint of heart, but if you can’t be convinced otherwise you can do it with today’s open source project of the day. https://github.com/mailcow/mailcow-dockerized Mailcow dockerized has everything you need to run your own email server (which is a a lot of stuff). It has spam filtering, built in TLS, webmail, IMAP and POP integration, multi account support and excellent docs. If you are using a third party email service like proton, your emails can be decrypted by the provider which is a security hole.