How do you interpret spam rate graphs in Gmail Postmaster?

Spam rate in Gmail Postmaster Tools indicates user complaint levels:

Below 0.1%: Healthy. Users are not marking your mail as spam.

0.1% to 0.3%: Concerning. Some users find your mail unwanted. Investigate.

Above 0.3%: Critical. You are generating significant complaints. Expect deliverability impact.

Above 0.5%: Emergency. Major reputation damage likely. Immediate action required.

Track trends over time. A spike after a specific campaign reveals what triggered complaints.

Your complaint meter. Keep it green, act fast when it turns yellow or red.