# Reject known spammers
smtpd_client_restrictions =
        permit_mynetworks,
        permit_sasl_authenticated,
        reject_rbl_client zen.spamhaus.org

# Require proper helo at connections
smtpd_helo_required = yes
smtpd_helo_restrictions =
        permit_mynetworks,
        permit_sasl_authenticated,
        reject_non_fqdn_helo_hostname,
        reject_invalid_helo_hostname,
        reject_rhsbl_helo dbl.spamhaus.org

# Reject malformed from: adresses
smtpd_sender_restrictions =
        permit_mynetworks,
        permit_sasl_authenticated,
        reject_non_fqdn_sender,
        reject_rhsbl_sender dbl.spamhaus.org

smtpd_relay_restrictions =
        reject_non_fqdn_recipient,
        reject_unknown_recipient_domain,
        permit_mynetworks,
        permit_sasl_authenticated,
        check_recipient_access pcre:/etc/postfix/dspam_check_aliases,
        check_sender_access pcre:/etc/postfix/dspam_check_aliases,
        # Reject mail when this server is not the final destination (don't be an open relay!)
        reject_unauth_destination,
        # Reject mail when the recipient doesn't exist on this server
        reject_unlisted_recipient,
        # Relay messages to DSPAM
        check_client_access pcre:/etc/postfix/dspam_filter_access

smtpd_data_restrictions = reject_unauth_pipelining