my_networks= my_hostname= smtpd_helo_required=yes smtdp_client_restrictions smtpd_helo_restrictions smtpd_sender_restrictions smtpd_relay_restrictions smtpd_recipient_restrictions smtpd_etrn_restrictions smtpd_data_restrictions smtpd_end_of_data_restrictions reject_unknown_client reject_unknown_client_hostname reject_unknown_reverse_client_hostname reject_unknown_helo_hostname reject_unknown_recepient_domain reject_non_fqdn_sender reject_non_fqdn_recipient reject_non_fqdn_hostname reject_invalid_hostname reject_unauth_pipelining reject_unauth_destination check_policy_service reject_non_fqdn_client