On Wed, Sep 01, 2021 at 04:05:55PM -0400, Steve Dondley wrote: > Thank you. Problem solved. For the benefit of others: > > 1) Add /etc/postfix/sender_checks file: > > amazonses.com OK > > 2) Add check to smtpd_recipient_restrictions config in main.cf: > > smtpd_recipient_restrictions = permit_mynetworks, > permit_sasl_authenticated, reject_unauth_destination, > check_sender_access hash:/etc/postfix/sender_checks check_policy_service > unix:private/policyd-spf > > 3) postmap sender_checks and reload postfix.
I would have opted for "client" rather than "sender" checks, provided a sufficiently stable/comprehensive range of source IP addresses for the forwarding host were available. -- Viktor.