smtpd_client_restrictions =
smtpd_helo_restrictions =
smtpd_sender_restrictions =
smtpd_recipient_restrictions =
        reject_non_fqdn_sender,
        reject_non_fqdn_recipient,
        reject_unknown_sender_domain,
        reject_unknown_recipient_domain,

        permit_mynetworks,
        permit_sasl_authenticated,
        reject_unauth_destination,

        reject_invalid_helo_hostname,
        reject_non_fqdn_helo_hostname,

        check_client_access hash:/etc/postfix/access_client,
        warn_if_reject reject_unknown_reverse_client_hostname,

        check_helo_access hash:/etc/postfix/access_helo,
        warn_if_reject reject_unknown_helo_hostname,

        check_sender_access hash:/etc/postfix/access_sender,
        check_recipient_access hash:/etc/postfix/access_recipient,
        reject_unlisted_recipient,

        # Absender pruefen
        reject_unverified_sender,

        # RBL
        # block_via_rbl,
        check_policy_service inet:127.0.0.1:10026,

        # Greylisting
        check_policy_service unix:private/postgrey,

        permit