KumoMTA Runtime Screen
Runtime metrics show whether KumoMTA is accepting, queueing, and reporting mail correctly.
Metrics to watch
- Injection attempts.
- Injection failures.
- In-flight injections.
- Circuit rejects.
- Alerts.
- Queue age.
- Tenant risk.
- Webhook accepted count.
- Webhook duplicate count.
- Webhook security failures.
- Redis dedupe hits.
How to read runtime health
| Signal | Healthy pattern | Investigate when |
|---|---|---|
| Injection attempts | Moves when PING8 sends. | No movement after a test send. |
| Injection failures | Stays near zero. | Any repeatable increase. |
| Queue age | Low and stable for normal traffic. | Age grows while volume is low. |
| Webhook accepted count | Increases after delivery events. | KumoMTA accepts mail but PING8 analytics stay empty. |
| Webhook security failures | Zero. | Any non-zero count after a config change. |
| Tenant risk | Stable. | Sudden change after a campaign or import. |
Healthy behavior
During a small test:
- Injection attempts increase.
- Injection failures stay at zero.
- Queue age remains low.
- Webhook accepted count increases after lifecycle events.
- Security failures stay at zero.
Warning signs
- Queue age keeps increasing.
- Injection failures rise.
- Security failures appear in webhook metrics.
- Duplicates grow unexpectedly.
- Tenant risk changes after a campaign.
What to do
- Pause new campaign volume.
- Check KumoMTA logs and queue summary.
- Check webhook secret and event endpoint reachability.
- Check DNS and provider-specific errors.
- Resume only after one-recipient tests pass.
Daily check
At the start of a send day:
- Refresh runtime metrics.
- Confirm queue age is low.
- Confirm no security failures appeared since the last send.
- Confirm the most recent test or campaign produced webhook events.
- Review provider-level failures before launching new volume.