Every week I talk to developers who ship transactional emails and assume the job is done after they paste an SPF record into DNS. Three months later, their password-reset emails land in spam and they have no idea why.
The silent failure
Unlike a 500 error that fires immediately, email deliverability degrades gradually:
- A new DMARC policy at a major mailbox provider tightens rejection rules.
- A shared IP pool gets flagged because another tenant sent spam.
- An SPF record grows past the 10-lookup limit and silently breaks.
None of these send you an alert. You find out when a customer tweets that they never received your invoice.
What the current tooling misses
Existing solutions fall into two camps:
- One-off checkers — You paste a domain, get a result, and never check again. There's no monitoring.
- Enterprise mail platforms — Postmark, SendGrid, and Mailgun have dashboards, but they only show data for mail sent through them. If your domain is used for phishing by a third party, you won't see it.
The pain point in one sentence
Developers have no way to be alerted when their domain's email authentication breaks — until a customer complains.
What a solution looks like
A lightweight background service that:
- Checks SPF, DKIM, and DMARC records on a schedule.
- Alerts via Slack/email when something changes or breaks.
- Shows a clear history so you can correlate policy changes with delivery drops.
Until automated monitoring is in place, the best defense is regular manual checks and a recurring reminder to re-verify your DNS records after any infrastructure change.
Quick self-check right now
You can verify your current setup using the free tools on this site:
- SPF Checker — validate your SPF record and lookup count
- DMARC Checker — inspect your DMARC policy and alignment
If either of those reveals something broken, fix it immediately — and schedule a monthly re-check, because DNS records change without warning.
Related reading
- Docker Containers Die Quietly — And Nobody Gets Paged — another silent production failure pattern