I did that a few years ago too. Then decided to just use OpenSMTPD instead of Postfix, keep Dovecot for IMAP and rspamd for signing DKIM. I followed the guide a

I did that a few years ago too. Then decided to just use OpenSMTPD instead of Postfix, keep Dovecot for IMAP and rspamd for signing DKIM. I followed the guide at https://prefetch.eu/blog/2020/email-server/ https://prefetch.eu/blog/2020/email-server/ and got it running relatively smoothly. However, Microsoft (and sometimes Google) kept blocking emails coming from my server's IP, so I just decided to stop messing around and pay migadu 19€ a year for dealing with that stuff for me.