Feedback Loop Configuration

What a feedback loop is

A feedback loop (FBL) is a service run by a mailbox provider. When one of its users reports your message as spam, the provider sends you a report, usually in the standard ARF (Abuse Reporting Format), containing a copy or partial copy of the reported message. Your system reads the report, identifies the recipient and suppresses them.

Without feedback loops, you often don’t know who complained until the cumulative effect shows up as poorer placement. With them, each complaint becomes an instant, specific action.

Who needs feedback loops

Anyone sending regular marketing or newsletter mail from their own infrastructure should register the feedback loops available to them. This matters most when:

• You run your own servers, such as Postfix, Postal or PowerMTA, rather than a cloud platform that handles FBLs for you.
• You use MailWizz or another self-hosted platform that needs a feedback-loop server configured.
• A meaningful share of your audience uses providers that offer feedback loops.
• You’ve added new sending domains or IPs that haven’t been registered yet.

Understanding coverage

Feedback loop availability varies, and it changes over time, so we check current programmes when we start rather than relying on an old list. In broad terms:

• Yahoo runs a complaint feedback loop for DKIM-signed mail from registered domains.
• Gmail doesn’t provide per-recipient reports. Its aggregate spam rate is visible in Google Postmaster Tools, and a Feedback-ID header can help large senders see complaint trends by campaign.
• Microsoft provides IP-level reputation and complaint data through SNDS for IPs you register.
• Various other providers and regional ISPs operate programmes of their own, some through third-party services.
• Cloud platforms such as Amazon SES collect complaint data where available and pass it to you as notifications.

Because coverage is incomplete, feedback loops always work alongside a one-click unsubscribe header and monitoring of aggregate data.

What’s included

• A dedicated mailbox or endpoint to receive feedback-loop reports.
• Registration with each available programme for your domains and IPs, including any verification steps.
• Automatic parsing of ARF reports to extract the recipient, list and campaign.
• Immediate suppression across all lists and brands.
• Configuration in MailWizz or your platform so reports are processed on schedule.
• Feedback-ID headers where useful for campaign-level trends.
• A coverage document listing which providers report, which don’t, and how each is monitored.

How we deliver it

1. Confirm DKIM signing and reverse DNS are in place, since several programmes depend on them.
2. Set up the reporting mailbox or endpoint.
3. Register domains and IPs with each available programme.
4. Configure parsing and suppression in your platform.
5. Verify with test reports or the first genuine reports that suppression happens.
6. Record registration details and renewal or re-verification needs.

Privacy and compliance notes

Some reports include parts of the original message and the recipient address. They should be treated as personal data under GDPR and India’s DPDP Act: stored only as long as needed, accessible only to people who need it, and used only to suppress and improve.

What affects timeline and cost

• Number of domains and IPs to register.
• Which programmes apply to your audience.
• Provider verification times, which we don’t control.
• Whether parsing is built into your platform or needs custom work.

Common mistakes

Registering once and forgetting new IPs or domains added later. Sending reports to a mailbox nobody’s platform reads. Suppressing only from the list that was reported. Assuming no reports means no complaints, when the provider may simply not run a loop.

Related: complaint handling, MailWizz installation and configuration, all email infrastructure services, the guide, and contact.

Frequently asked questions