Failed emails are automatically retried with exponential backoff:
- Soft bounces: Retried up to 3 times over 24 hours
- Temporary failures: Retried up to 5 times over 48 hours
- Hard bounces: Not retried (permanent failure)
Retry Schedule:
- Immediate retry (0 minutes)
- Second attempt (15 minutes)
- Third attempt (1 hour)
- Fourth attempt (4 hours)
- Final attempt (24 hours)
After all retries are exhausted, the email status becomes failed.