Complaints suppress the complainer instantly and feed the health model. Keep complaint rate under 0.1% (1 in 1,000). Above 0.3%, sending on the affected mailbox pauses automatically. Root cause is almost always audience quality.
What happens on a complaint
Immediate permanent suppression of the complainer, exit from all sequences, negative weight in the mailbox health model, and inclusion in the complaint-rate metric that providers watch.
The thresholds
- Under 0.1% — healthy.
- 0.1–0.3% — warning: the dashboard flags the sequences and audience sources generating complaints.
- Above 0.3% — automatic sending pause on the affected mailbox pending review.
Root-cause analysis
Complaints trace to audience-message mismatch: too-broad targeting, stale lists, or aggressive cadence. The complaint report shows which sequence and audience source each complaint came from — fix there.
Recovery
After fixing the source: resume at reduced volume, emphasize your most-engaged segments for two weeks to rebuild engagement ratios, and let the throttle loosen as complaint-free sends accumulate.
