# client # sender # recipient # relay smtpd_client_restrictions= smtpd_sender_restrictions= smtdp_recipient_restrictions= smtpd_relay_restrictions smtpd_helo_restrictions smtpd_data_restrictions smtpd_end_of_data_restrictions smptd_etrn_restrictions my_networks= my_hostname= smtpd_helo_required=yes # unknown reject_unknown_client reject_unknown_client_hostname reject_unknown_reverse_client_hostname reject_unknown_helo_hostname reject_unknown_hostname reject_unknown_sender_domain reject_unknown_recipient_domain # hostname reject_unknown_client_hostname reject_unknown_reverse_client_hostname reject_unknown_helo_hostname reject_unknown_hostname reject_invalid_hostname reject_non_fqdn_hostname # sender reject_unknown_sender_domain reject_non_fqdn_sender # recipient reject_unknown_recipient_domain reject_non_fqdn_recipient # non_fqdn reject_non_fqdn_hostname reject_non_fqdn_recipient reject_non_fqdn_sender reject_unauth_pipeling reject_unauth_destination check_policy_service