Privacy-wise, personally, I'd just love to see what are my options for self-hosted email service. Presently it's just Postfix and Dovecot on the physically-own

Privacy-wise, personally, I'd just love to see what are my options for self-hosted email service. Presently it's just Postfix and Dovecot on the physically-owned server and Thunderbird and K9 Mail on desktop and mobile. Quite old-fashioned. I had seen links to some fastmail support branch for cyrus and some jmap.io, but didn't really get what thase are and all on Fastmail's website suggests it's a service, not software. But maybe I had missed something. So... is it for me or not?