smtpd_client_restrictions smtpd_sender_restrictions smtpd_relay_restrictions smtpd_data_restrictions smtpd_end_of_data_restrictions smtpd_etrn_restrictions smtpd_helo_restrictions # hostname reject_unknown_client_hostname reject_unknown_reverse_client_hostname reject_invalid_hostname reject_unknown_helo_hostname reject_unknown_hostname # unknown reject_unknown_client_hostname reject_unknown_helo_hostname reject_unknown_sender_domain reject_unknown_recipient_domain reject_unknown_helo_hostname reject_unknown_hostname # non_fqdn reject_non_fqdn_sender reject_non_fqdn_recipient reject_non_fqdn_client permit_my_networks # unauth reject_unauth_pipelining reject_unauth_sender_domain