Olá Filipe. Tente por essas regras no submission, no master.cf: submission inet n - - - - smtpd -o smtpd_recipient_restrictions = check_sender_access hash:/etc/postfix/send_restritos... -o smtpd_restriction_classes = send_local -o send_local = check_recipient_access hash:/etc/postfix/domains_send, reject
Olá Filipe.
Tente por essas regras no submission, no master.cf: