Feedback Loops (FBL): How Senders Know You Clicked 'Spam'

Introduction: The Direct Line

If millions of people click the 'Spam' button on a particular newsletter, the email provider (like Microsoft) will block the sender's IP address. But how does the sender know they are angering people before they get blocked entirely? They register for a Feedback Loop (FBL).

The Automated Warning

An FBL is an agreement between the sending IP and the Inbox provider. When a user clicks 'Report Spam', Microsoft automatically forwards that complaint back to the original sender's server (with the user's name hidden). The sender's software automatically unsubscribes that user to protect the overall health of the sending IP.

Conclusion

Feedback Loops ensure that the 'Spam' button isn't just a black hole—it is a live, automated signal that keeps IP reputations clean. Check your bounce rates here.