Guides · Deliverability

Setting up feedback loops

A feedback loop (FBL) is a service from a mailbox provider that tells you when one of their users marks your email as spam. That signal is gold: it lets you stop emailing complainers immediately, which protects your reputation. This guide explains how the major providers' loops work and how to set them up.

Why feedback loops matter

Your spam-complaint rate is one of the strongest signals mailbox providers use — Google asks senders to keep it under 0.30% and ideally below 0.10%. You can only manage what you can measure, and a feedback loop is how you measure (and react to) complaints. When someone complains, the right move is to suppress that address so you never email them again.

ℹWhat BlacklistGuard does for you: we sign your mail with DKIM using your verified sending domain — the prerequisite for the domain-based loops below — and hard bounces are suppressed automatically. You set up the feedback loops below with your own reporting address, and suppress the complainers you receive (see Acting on complaints).

Microsoft (Outlook, Hotmail, Live)

Microsoft's feedback loop is the Junk Mail Reporting Program (JMRP), offered alongside Smart Network Data Services (SNDS), which reports reputation and complaint data for your sending IPs. When an Outlook.com user marks your mail as junk, JMRP forwards a copy to an address you nominate.

JMRP is tied to the sending IP address, and enrollment is verified against the IP's WHOIS abuse@ contact — so only the owner of the IP can enroll it. Sign up at Microsoft's SNDS portal (JMRP enrollment).

ℹBecause JMRP is per-IP, it's handled at the infrastructure level. On BlacklistGuard's shared pool the IPs are ours and we manage this. If you're on dedicated IPs, contact support about feedback-loop enrollment for them.

Yahoo (and AOL)

Yahoo's Complaint Feedback Loop (CFL) covers Yahoo and AOL mailboxes. Unlike Microsoft's, it is domain-based and requires your mail to be DKIM-signed — which BlacklistGuard does for your verified sending domain. When a user marks your mail as spam, Yahoo sends a report in ARF (Abuse Reporting Format) to the address you enrolled.

Enroll at the Yahoo Sender Hub:

Create a Sender Hub profile.
Add and verify your domain — enroll the exact domain that DKIM-signs your mail (your verified sending domain), not just your visible From domain.
Enroll that domain in the Complaint Feedback Loop, and verify the reporting mailbox where you want the ARF reports delivered.

Gmail

Gmail's feedback loop is different: it does not send a report for every complaint. Instead it gives aggregate complaint data, per campaign, inside Google Postmaster Tools. To use it:

Your mail must be DKIM-signed by a domain you own, and that domain must be added and verified in Postmaster Tools.
Messages carry a Feedback-ID header (format a:b:c:SenderId, where SenderId is a consistent 5–15 character identifier). Gmail then reports the spam rate per identifier in the Postmaster Tools FBL dashboard.
The data covers @gmail.com recipients only.

ℹBlacklistGuard automatically adds the Feedback-ID header to your campaign and autoresponder mail, so per-campaign spam rates appear in the Postmaster Tools FBL dashboard — you just need to register your sending domain there to see them. (One-off transactional sends via the API don't carry it. Gmail's data is aggregate, so it powers the spam-rate view rather than per-message suppression.)

Acting on complaints

However you receive them, the response is the same: suppress the complainer immediately and never email them again. When a feedback-loop report arrives at your reporting mailbox, add that address to a suppression list — by hand, or automate it via the API. Then look for patterns — a campaign or segment driving a complaint spike is telling you something about your content or targeting. (Hard bounces are already suppressed for you automatically.)