A feedback loop (FBL) in email marketing is a mechanism provided by internet service providers (ISPs) that reports spam complaints made by recipients back to the sender. It helps organizations monitor user complaints and maintain a healthy sender reputation.
A feedback loop is a system where ISPs notify email senders when their recipients mark an email as spam or junk. The report usually includes details like the recipient’s email address (in a hashed or anonymized format), the original message ID, and complaint metadata.
Email service providers (ESPs) and high-volume senders use FBLs to:
Most major ISPs, including Yahoo, Microsoft, and AOL, offer feedback loop services, but senders must apply and meet specific requirements, such as implementing authentication protocols like SPF, DKIM, and DMARC.
The feedback loop process typically involves:
This closed-loop process helps reduce complaint rates and protect sender reputation.
FBLs are critical because they:
Without feedback loops, senders may remain unaware of rising complaint rates, leading to deliverability issues.
Feedback loops are used by:
Example scenario: An e-commerce brand enrolls in Yahoo’s feedback loop program. When recipients mark promotional emails as spam, the brand receives real-time reports and removes those addresses from its mailing list.
No. Major ISPs like Yahoo and Microsoft do, but Gmail uses engagement-based filtering without traditional FBL reports.
Generally, a spam complaint rate above 0.1% is considered problematic by most ISPs.
