It's clear now.
Postfix checks restriction rules in order, so you can try to move 'check_client_access hash:/etc/postfix/rbl_override' to the front of 'reject_unauth_destination', then reload Postfix service and try again.
It's clear now.
Postfix checks restriction rules in order, so you can try to move 'check_client_access hash:/etc/postfix/rbl_override' to the front of 'reject_unauth_destination', then reload Postfix service and try again.