We run a large newsletter and we use Google Postmaster to track feedback loops. We followed all instructions and correctly configured our domain in Google Postmaster. We also add a custom header to all emails sent:
Feedback-ID: $template:$domain:$email_to:$server
However, in Google Postmaster our FBL spam rate is always zero which is impossible because we send to over 100k subscribers so we usually get between 0% to 0.5% spam reports
But if I look at the "Spam Rate" graph (non-FBL) then I see non-zero values
