Free tool

SPF DKIM DMARC checker for cold email

Run the three core authentication checks together before a cold email campaign goes live: SPF, DKIM, and DMARC.

This checks SPF, DKIM, and DMARC for one domain. For a real launch verdict, run every domain, inbox, and tracking domain through the full QA pass.

Runs live in your browser via public DNS. Nothing is stored.

Turn three DNS checks into one launch decision

Authentication is where agencies often lose time between a setup screenshot and a real client approval. Use this check to identify the first record owner action, then retain a fresh rerun as proof that the sending domain is configured for the launch.

How to read the authentication result

A launch-ready sending domain needs one valid SPF record, a DKIM key for the selector your sending platform uses, and a DMARC record at _dmarc.yourdomain.com. This checker runs all three lookups together so you can spot missing records before an outbound campaign starts.

Treat warnings as launch risk, not trivia. A p=none DMARC policy may be acceptable during setup, and a DKIM CNAME can be valid, but both need a deliberate review before you send volume.

Where this fits in cold email QA

SPF, DKIM, and DMARC prove the domain is authenticated. They do not prove the inbox can receive replies, the tracking domain has valid SSL, the domain is clear of blacklists, or the full workspace is ready to launch.

For a single domain, use this as the authentication checkpoint. For a real launch, run the full OutboundQA pass across every sending domain, inbox, and tracking domain so the team has a verdict and a shareable report.

What this check does not catch

A passing SPF, DKIM, and DMARC lookup is useful, but it is not launch signoff. Cold email campaigns still fail when adjacent records, tracking domains, or inbox-level settings are broken.

MX readiness

tracking-domain SSL

blacklist status

domain age

inbox-level setup

Google and Yahoo sender requirements

Setup guides for this check

Read the setup notes behind this result, then verify the neighboring records before launch.

SPF for cold email

The exactly-one-record rule, the 10 DNS lookup limit, and the SPF mistakes that block a launch.

DKIM for cold email

Selectors, public keys in DNS, and DKIM setup for Google Workspace and Microsoft 365.

DMARC for cold email

Policies, alignment, rua reports, and the Gmail and Yahoo requirement that made DMARC mandatory.

Google and Yahoo bulk sender requirements

SPF, DKIM, DMARC, one-click unsubscribe, and the spam-rate thresholds bulk senders must meet.

Need to check a full outbound workspace?

OutboundQA checks every domain, inbox, and tracking domain in the workspace, then gives you a shareable report with a Ready, Needs Fix, or Do Not Launch verdict.

Run a free workspace check View a sample report

Cold email launch checks to run next

Use this result as one checkpoint in the launch flow. Then verify the neighboring records and run the combined domain check before the outbound launch goes live.

SPF Checker

Look up a domain's SPF record and count its DNS lookups against the limit of 10.

DMARC Checker

Look up a domain's DMARC record and read its policy in plain English.

DKIM Checker

Look up a domain's DKIM selector and confirm the public key exists.

MX Checker

Look up a domain's MX records and detect the mail provider.

Blacklist Checker

Check a domain and sampled mail server IPs against domain and email blocklists.

Reputation Checker

Check observable cold email reputation risks across age, blacklist, authentication, MX, and HTTPS signals.

Deliverability Checker

Check observable cold email infrastructure readiness across MX, SPF, DKIM, DMARC, blacklist, age, tracking-domain, and SMTP egress identity signals.

Receiver Checker

Check observable Gmail, Yahoo, and Microsoft sender requirements from public DNS and optional pasted message headers.

Recipient Preflight

Paste emails or domains and classify MX provider, free inboxes, security gateways, SPF, DMARC, and receive-mail readiness.

Tracking Checker

Check a branded cold email tracking domain for CNAME setup, DNS resolution, HTTPS, and redirect handoff.

MTA-STS Checker

Check MTA-STS and TLS-RPT records for inbound mail security posture before a cold email launch.

PTR/rDNS Checker

Check a custom SMTP egress IP for PTR, reverse DNS, and forward-confirmed rDNS before launch.

Launch Checklist

Generate a pre-launch QA checklist for domains, inboxes, authentication, tracking domains, blacklist checks, and signoff.

Domain Checker

Run MX, SPF, and DMARC in one pass for a quick readiness verdict on a sending domain.

Burn History

Check whether a domain has already sent cold email, carried a tracking hostname, or picked up a listing, before you buy it.

Sample Launch QA Report

See the report founders, teams, and agencies can share after the full QA pass.

Email Deliverability Tool

See how one-off checks turn into pre-launch QA for full cold email workspaces.

Questions

It checks the three authentication records receivers use to decide whether mail is allowed, signed, and covered by a domain policy. SPF lists approved senders, DKIM verifies the message signature, and DMARC tells receivers what to do when authentication fails.

DKIM records are published under a selector, such as google, selector1, s1, or a provider-specific value. The selector has to match the platform that will send the campaign, so a real DKIM check needs both the domain and selector.

No. Passing authentication is necessary, but it is not full launch signoff. A full check also covers MX, tracking-domain SSL, blacklist status, domain age, inbox setup, and Google/Yahoo sender requirements across the workspace.

Assign the record owner, fix the failing authentication record, and rerun the same checks with the selector and sending domain that will launch. Record the fresh result beside the client launch decision instead of relying on a one-time lookup.

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