Common Bounce Messages to Create Rules For
| Message Pattern | Type | Suggested Count | Suggested Interval | Action |
|---|---|---|---|---|
| "mailbox full" | Quota | 3-5 | 7-14 days | Suppress |
| "would exceed quota" | Quota | 3-5 | 7-14 days | Suppress |
| "user unknown" | Invalid | 1 | Any | Suppress immediately |
| "does not exist" | Invalid | 1 | Any | Suppress immediately |
| "temporarily deferred" | Throttle | 10 | 1 day | Monitor, don't suppress |
| "rate limit" | Throttle | 10 | 1 day | Reduce sending speed |
| "blocked" | Reputation | 3 | 7 days | Review sender reputation |
Tips
- Start with higher thresholds (5+ bounces) and tighten over time
- Use shorter rolling intervals (7 days) for quota-related bounces
- Use longer intervals (30 days) for intermittent issues
- Always check Delivery Events for the exact message text before creating rules