Reported Spam

What is Reported Spam?

Reported spam refers to messages that recipients actively marked as spam or junk using the "report" button in their email client. These clicks generate formal complaints that are fed back to the sending platform, usually through feedback loops provided by major mailbox providers.

Why it matters

A complaint is the strongest negative signal a recipient can send. Mailbox providers weight complaint rate heavily when scoring sender reputation, and rates above 0.1 percent are enough to start hurting placement. Above 0.3 percent, Gmail will actively filter your mail. Marketers and deliverability engineers must monitor and react to complaints immediately.

How it works

Mailbox providers operate feedback loops, or FBLs, that forward spam reports back to the sending IP's operator. The sending platform parses these reports, extracts the recipient address, and adds it to the suppression list with a complaint reason. Gmail does not offer a public FBL for individual complaints but provides aggregate complaint data through Postmaster Tools.

Examples

• A campaign with a 0.4 percent complaint rate triggering a Gmail throttle
• A platform receiving 12 complaints from a single send, auto-suppressing all 12
• A deliverability team spotting a new complaint spike after a subject line change

Best practices

• Target a complaint rate under 0.1 percent at all mailbox providers
• Never re-engage addresses that filed a complaint
• Make your unsubscribe link more prominent than the subject line itself
• Connect Sendkit to all available feedback loops so complaints feed suppressions automatically

FAQs

Why do recipients report mail as spam instead of unsubscribing?

Because the report button is often more visible and faster than finding the unsubscribe link. Make unsubscribe obvious to reduce this behavior.

Does Gmail send me complaints through a feedback loop?

No. Gmail does not provide per-message FBL data. Use Google Postmaster Tools to see aggregate complaint rates for your domain.

What complaint rate will hurt my sending?

Above 0.1 percent is a warning, above 0.3 percent is a crisis. Keep it below 0.1 percent as a working target.