03 / 06
Outbound deliverability
Live MVP
Outbound Infrastructure Guardrail System
A policy-driven monitor that converts live DNS authentication and sending-health data into ALLOW, THROTTLE, or PAUSE decisions.
3operating decisions
Tool stack
- n8n
- Google Sheets
- Google DNS API
- JavaScript
01
The bottleneck
Outbound teams often discover SPF, DMARC, MX, bounce, or spam issues only after deliverability falls. At that point, inbox placement and pipeline are already at risk.
02
System design
From input to action, with every decision visible.
- 01
Pulled live SPF, DMARC, MX, and optional DKIM data through Google DNS-over-HTTPS and combined it with sending-health metrics.
- 02
Moved warning and critical thresholds into a separate policy sheet so operators can change rules without editing the workflow.
- 03
Built a JavaScript decision engine in n8n that returns one consistent operating decision with a reason.
- 04
Designed the system for scheduled monitoring, alerting, and future auto-pause integrations with sending platforms.
03
Outcomes
What changed because the system existed.
- Three clear operating states replace subjective per-domain checks.
- Authentication failures and unhealthy metrics surface before the next outbound run.
- Live DNS logic is separated honestly from the controlled test data used for the MVP's sending metrics.