My core email is still postfix and dovecot and has been for a long time now. There is extra stuff to support dkim, spf, mta-sts, cert renewals, spam, abuse etc. We use native imap clients. No webmail or calendaring or integration with office/document stuff. Run a totally separate system for end to end encrypted messaging, group chat etc. Not really big into the self hosting thing except as a means to an end. Less is more for me but mail isn't much of a hassle in return for a lot of control.