# postfix

**Outbound-only** SMTP relay. Used by grafana alerts, node-red flows, jenkins build notifications.

- **Network**: `app` (internal services hit `smtp://postfix:25`)
- **Ingress**: none — no port published, no listener facing internet
- **Egress**: TCP/25 outbound to internet MX servers (or a smart-host relay)
- **TODO**: SPF/DKIM/DMARC for `${POSTFIX_FROM_DOMAIN}`, smart-host config if WBD provides a relay