smtpd_helo_restrictions =
        permit_mynetworks,
        permit_sasl_authenticated,
        reject_non_fqdn_hostname,
        reject_invalid_hostname,
        permit

smtpd_client_restrictions =
        permit_mynetworks,
        permit_sasl_authenticated,
        warn_if_reject reject_unknown_client,
        permit

smtpd_sender_restrictions =
        permit_mynetworks,
        reject_non_fqdn_sender,
        warn_if_reject reject_unknown_sender_domain,
        permit

smtpd_recipient_restrictions =
        permit_mynetworks,
        permit_sasl_authenticated,
        reject_unauth_pipelining,
        reject_non_fqdn_recipient,
        reject_non_fqdn_sender,
        warn_if_reject reject_unknown_recipient_domain,
        warn_if_reject reject_unknown_sender_domain,
        reject_unauth_destination,
        reject_rbl_client zen.spamhaus.org,
        reject_rbl_client dnsbl.njabl.org,
        reject_rbl_client cbl.abuseat.org,
        permit

smtpd_data_restrictions =
        reject_unauth_pipelining,
        permit