Complaint Feedback Loop program
Yahoo Mail offers a free Complaint Feedback Loop program to help email senders minimize complaint rates. If you participate, Yahoo Mail forwards complaints from our users about emails sent from your organization.
Program goals
This program aims to help senders:
Understand what Yahoo Mail users think of their messages.
Take corrective action to minimize the complaints generated by their mailings.
Improve their sending reputation.
Participation eligibility
To be eligible, email senders must:
Sign their outbound emails with DomainKeys and/or DomainKeys Identified Mail (DKIM).
Have a Yahoo ID. Learn how to sign up for a Yahoo Account.
Sign up or update your CFL
Fill out a new CFL application to enroll in the program, or to update an existing CFL.
When you sign up for or update an existing Complaint Feedback Loop you'll need to enter a verification code. This code can only be sent to:
postmaster@(your domain)
This verification process is necessary to activate any domain for the feedback loop.
Turn off CFL reports
You can turn off your service if you no longer want to receive reports. Fill out the CFL application and under “Request type,” select Delete. Once your submission is processed, you’ll stop receiving them.
https://help.yahoo.com/kb/yahoo-complaint-feedback-loop-program-sln3438.html