Domain tools

Domain analyzer

Get a complete email authentication picture for any domain, MX, SPF, DKIM, DMARC, and DNS propagation.

About

The Domain Analyzer runs a full deliverability audit on any domain, checking MX routing, SPF authorization, DKIM signing, and DMARC policy in one pass.

Use it when onboarding a new sending domain, troubleshooting deliverability, or confirming all authentication records are present before a campaign launch.

MX and mail routing

See whether the domain accepts mail and which hosts receive inbound messages.

SPF, DKIM, and DMARC together

Get a unified view of all three authentication layers instead of checking each tool separately.

Selector auto-detect

Probe common and inferred DKIM selectors automatically, or specify your own.

DNS propagation check

Optionally compare resolver answers to spot records still propagating after DNS changes.

How to use this tool

Enter your domain

Type the root domain, for example example.com, without http:// or a subdomain prefix.

Configure DKIM options

Enable Auto Detect to probe inferred selectors, or enter specific selectors separated by commas.

Run the analysis

The tool queues a background job that looks up MX, SPF, DKIM, and DMARC records from public DNS.

Review the summary

Read the overall grade, per-protocol status cards, issues, and optional propagation consensus.

Understanding the results

Results reflect live public DNS. Analysis runs as a background job and may take up to a minute when propagation checks are enabled.

Healthy configuration

Records are present and valid with no critical issues. Grades of A or B indicate strong authentication posture.

Present but needs attention

Records exist but have warnings, for example SPF softfail (~all), missing DKIM selectors, or p=none DMARC policy.

Missing or invalid

A required record was not found or has syntax errors that receivers may ignore.

DNS propagation divergence

When enabled, propagation checks flag resolver disagreements, DNS may still be updating after a recent change.

Important result fields

Overall grade

Combined score reflecting MX, SPF, DKIM, and DMARC health.

MX

Whether mail exchanger records exist and point to valid hosts.

SPF

The published SPF TXT record, lookup count, terminal policy, and any issues.

DKIM

Whether signing keys were found for probed selectors, with grade and issue details.

DMARC

The published policy record, enforcement level (p=), and reporting configuration.

DNS propagation

Consensus across resolvers for MX, SPF, and DMARC when the option is enabled.

Best practices & recommendations

Run before every major send

Confirm all four protocols are healthy before launching campaigns on a new or recently changed domain.

Use auto-detect first

Let the tool infer DKIM selectors from SPF and MX signals before manually entering selectors.

Enable propagation after DNS edits

Turn on propagation checks after publishing or updating records to confirm global consistency.

Drill into individual tools

Use the SPF, DKIM, and DMARC checkers for deeper tag-level detail on any section that shows issues.

Frequently asked questions

It combines MX, SPF, DKIM, and DMARC into one report with an overall grade. Individual checkers provide deeper detail on a single protocol.

Propagation checks query multiple public resolvers and compare answers. This adds time but helps confirm DNS changes have reached the internet.

It probes DKIM selectors inferred from your SPF includes, MX hosts, and common ESP naming patterns instead of requiring you to know every selector.

Yes. The job continues in the background. If you refresh the page, analysis resumes automatically from where it left off.

The domain may not publish DKIM, selectors may be non-standard, or DNS has not propagated. Try entering known selectors manually.

MX records handle inbound mail. Outbound deliverability depends on SPF, DKIM, and DMARC, but missing MX can indicate an incomplete domain setup.

After any DNS change, ESP migration, or deliverability incident. Monthly audits are a good baseline for active sending domains.

Run this check once, or have it watched 24/7.

SenderSignal monitors these signals continuously: 48 blacklists, SPF, DKIM, DMARC, TLS and more, with alerts in Slack, email and signed webhooks.

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