What is an acceptable email bounce and complaint rate?
Keep bounce rate under 5% and complaint rate under 0.1%. Above those, Amazon SES flags accounts for review and mailbox providers begin throttling. Above 10% bounce or 0.5% complaint, accounts are commonly suspended. AeroCampaign shows a rolling 30-day rate against exactly these thresholds — amber at 5% / 0.1%, red at 10% / 0.5% — so the warning arrives at the same time the provider sees it.
- Healthy: bounce under 5%, complaint under 0.1%.
- Warning: bounce 5–10%, complaint 0.1–0.5%.
- Critical: bounce above 10%, complaint above 0.5%.
- These mirror the levels at which Amazon SES places accounts under review.
- AeroCampaign computes the rate on a rolling 30-day window, overall and per provider.
Complaint rate is the more dangerous of the two because the tolerance is so small. At 0.5%, one complaint in every two hundred delivered messages is enough to put an account at risk, which a single badly targeted send to a stale segment can produce.
Bounce rate is usually a list-hygiene problem rather than a content problem, which is why cleaning and suppression are bundled rather than sold as an add-on.