Our relay servers running postfix are configured to block NDRs by default - unless from listed IP addresses.
This is done by having smptd_sender_restrictions with check_client_access (with the IP database of 'xx.xx.xx.xx OK') and then check_sender_access (with a database including '<> REJECT')
We have a client on a dynamic IP who needs to send NDRs (i.e. From <>) to a specific email address...
Question: where in postfix can I put a 'check_recipient_xxxxx' type check that will allow an 'OK' status and short-circuit the rest of the sender/client-restrictions?