Figure I'd ask here, but I'm looking to set something up for email in the future, I'm looking into custom domains so that if something happens with one email account, then I have more security in mind to pick up from there as opposed to being screwed.
I know that fully self hosting email full stop is usually not recommended, so I'm up for any advice anyone has on that end.
Assuming that you do want to fully self host, my go-to is a postfix+mariadb+postfixadmin+spamassassin+opendkim stack. With rainloop as a webmail if required.
Avoid exim like the plague