smtpd_recipient_restrictions =
...
reject_unauth_destination
# Check rDNS in domain blacklist (optional)
reject_rhsbl_client <APIKEY>.dblack.mail.abusix.zone
# Check HELO/EHLO in domain blacklist (optional)
reject_rhsbl_helo <APIKEY>.dblack.mail.abusix.zone
# Check FROM domain in blacklist (optional)
reject_rhsbl_sender <APIKEY>.dblack.mail.abusix.zone
# Check connecting IP in whitelist (optional)
# permit_dnswl_client entries should be placed before any reject directives
# that want to skip, but should always be before any reject_rbl_client
# entries to ensure that any IP listed on the whitelist not rejected.
permit_dnswl_client <APIKEY>.white.mail.abusix.zone
# Reject any IP listed in the blacklist
reject_rbl_client <APIKEY>.combined.mail.abusix.zone
rbl_reply_maps = texthash:/etc/postfix/rbl_reply_map