Product6 min read

Free domain monitoring

Daily checks on SPF, DKIM, DMARC, PTR, MX, A records and major blacklists. Alerts when anything changes. Free.

Domain reputation dies in increments: a DKIM selector accidentally removed, a new MX added during a migration, an IP landing on Spamhaus because a mail-list member got compromised. Without monitoring you find out via placement dropping a week later.

What's monitored daily (free)
  • SPF record (content + includes + lookup count).
  • DKIM public key presence for your active selectors.
  • DMARC policy, reporting targets, sub-policy.
  • PTR for your sending IP(s).
  • MX, A, AAAA records (unexpected changes).
  • MTA-STS and TLS-RPT publication.
  • Major blacklists: Spamhaus, Spamcop, SURBL, Barracuda, SORBS, URIBL.
  • Domain expiration.

Alerts

  • Email on change (instant).
  • Slack/Teams webhook (on paid plan — free via Zapier through our OAuth).
  • Weekly digest (free, opt-in).
  • MCP tool: monitor_domain — an agent can subscribe and fetch state.

Why “free” is harder than it sounds

Domain monitoring is resource-intensive. DNS queries are cheap individually, but done daily across many domains + blacklists + selector rotation adds up. Most competitor tools bundle this as a paid add-on because the infrastructure cost is non-trivial.

We run it free because we already maintain the DNS/auth/blacklist infrastructure for placement tests — domain monitoring rides on top at near-zero marginal cost. You benefit from the scale.

Add a domain to monitoring

Add your sending domain and receive the first report within 24 hours. No credit card, no trial.

FAQ

How many domains can I monitor for free?

Up to 10 per account. More on request — email us; if it's for legitimate deliverability work, it's yours.

Do you support custom selectors?

Yes — name them in the domain setup. We poll every selector you add.

Can I pipe alerts into PagerDuty/Datadog?

Via our webhooks on the paid plan, or via Zapier/Make using our free OAuth integration.
Related reading

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