@atpfm Instead of shutting down self mail hosting with FUD, why don’t you just say that you haven’t done it in a long time and have no idea what to do. I’ve been doing it on and off for nearly thirty years and it is easier than ever thanks to systems such as DMARC, DKIM, SPF, etc. Try it before you shut it down with so little information (postfix, opendmarc, opendkim, pfadmin, spamassassin, dovecot, etc.).