Migration zu self-hosted Mail ist kein Wahnsinn mehr.
Stack
Postfix, Dovecot, Rspamd, ClamAV, Roundcube/SOGo.
Beispiel: Postfix main.cf
Die wesentlichen main.cf-Einstellungen (TLS, DKIM, RBL-Anti-Spam):
# /etc/postfix/main.cf — esential
myhostname = mail.example.com
smtpd_tls_security_level = may
smtpd_milters = inet:localhost:8891 # OpenDKIM
smtpd_recipient_restrictions =
permit_mynetworks,
reject_unauth_destination,
reject_rbl_client zen.spamhaus.org