i copie the line here
/etc/postfix/main.cf
smtpd_sender_restrictions = check_sender_access hash:/var/spool/postfix/plesk/blacklists, check_sender_access hash:/var/spool/postfix/plesk/custom-added-blacklist, permit_sasl_authenticated
/var/spool/postfix/plesk/custom-added-blacklist
/\.xyz$/...