Every message generates structured JSON events: Received, Delivered, Bounced, TransientFailure, Expiration, FeedbackReport.
Sample log line:
{
"type": "Delivered",
"id": "01HC8X...",
"timestamp": 1748908800.123,
"sender": "newsletter@example.com",
"recipient": "alice@gmail.com",
"domain": "gmail.com",
"tenant": "acme-marketing",
"campaign": "blackfriday-2026",
"response": { "code": 250, "enhanced_code": "2.0.0", "content": "OK" },
"queue": "gmail.com.acme-marketing.blackfriday-2026",
"egress_source": "ip-3",
"session_id": "abc...",
"headers": { "Message-ID": "<...>" }
}
Default log destinations:
/var/log/kumomta/kumod.log— rotated- Webhook hooks for streaming
Recommended pipeline: KumoMTA → Vector → ClickHouse / S3 / Loki. Vector handles batching, retries, and schema enforcement.
Sign in to keep track of what you have read.