How does M3AAWG define acceptable complaint behavior?

If you've ever wondered what separates a sender with a healthy reputation from one on the path to getting blocked, complaint rates are a big part of the answer. M3AAWG (the Messaging, Malware and Mobile Anti-Abuse Working Group) has published Sender Best Common Practices that spell out exactly what they consider acceptable.

The headline number is 0.1%. That's M3AAWG's target for complaint rates. Stay below that and you're in good shape. Once you're approaching 0.3%, M3AAWG treats that as a signal requiring immediate attention. Not "keep an eye on it" attention. Actual fix-it-now attention.

But the thresholds are only part of the picture. What M3AAWG also defines is what good complaint handling looks like after the spam report lands.

• Suppress immediately. The moment a complaint comes in, that address should never receive another email from you. No exceptions, no "one more send" before the suppression kicks in.
• Investigate the pattern. One complaint is noise. Ten complaints from the same campaign, or clustering around a specific segment, is a signal. Something's off with the content, the targeting, or the original consent.
• Participate in feedback loops. M3AAWG strongly recommends that senders sign up for feedback loops (FBLs) with mailbox providers. These give you the complaint data you need to act. Without FBL data, you're flying blind.
• Process FBL reports before your next send. Getting the report but waiting until next week to suppress the complainers means they'll get hit again. That compounds the damage to your reputation fast.

The spirit behind all of this is consent and responsiveness. M3AAWG's view is that complaints are your subscribers telling you something. Either they didn't want the email, or they've forgotten they signed up, or the content missed the mark. Your job is to listen (and suppress) quickly.

If your complaint rate is already creeping up, our SOS hotline is free. We can help you figure out whether it's a list quality issue, a content problem, or something in your sending setup that needs fixing.