smtpd_recipient_restrictions=check_sender_access hash:/etc/postfix/users_restritos , reject_unauth_destination
smtpd_restriction_classes=local_only
local_only=check_recipient_access hash:/etc/postfix/local_domains , reject
local_recipient_maps=

----------------------------

server:/etc/postfix# cat users_restritos
domain1.com.br                local_only

----------------------------
server:/etc/postfix# cat local_domains
domain1.com.br                OK