Volume spike
A sudden day-over-day traffic jump that looks unlike natural growth.
Problem summary
A sudden day-over-day traffic jump that looks unlike natural growth.
Symptoms
- Single-day volume many times the recent baseline
- Immediate filtering after a campaign burst
Possible causes
- Misconfiguration
- Incomplete rollout
- DNS propagation delay
How to diagnose
- Confirm the symptom in headers or reports
- Inspect the relevant DNS records
- Validate with a trusted checker
How to fix
- Correct the DNS or signing configuration
- Re-test and confirm alignment where required
How to verify
- Re-check DNS
- Send a test message
- Confirm expected authentication results
Prevention
- Document changes
- Monitor reports after deployment
When to escalate
- Production mail is failing authentication after a change window