SPF, DKIM & DMARC checker

Enter a sending domain to see its email authentication records — and what each result actually means, rather than a green tick with no explanation.

Why these three records decide your fate

Cold email copy gets endless attention while authentication gets almost none, which is backwards. A domain with no DMARC record sending from a fresh IP will land in spam no matter how well the email is written. These records are the foundation everything else sits on.

Since 2024, Google and Yahoo have required SPF, DKIM and DMARC for bulk senders. Cold outreach at any volume falls squarely inside that.

What each one does

SPF — who is allowed to send: A DNS record listing the servers permitted to send as your domain. Two failure modes matter: having more than one SPF record breaks it entirely (receivers return a permanent error rather than merging them), and ending in +all authorises the whole internet — worse than having none.
DKIM — proof it was not altered: A cryptographic signature on each message, verified against a public key in your DNS. Records live at selector._domainkey, and selectors cannot be enumerated — so this tool probes the common ones used by Google, Microsoft, SendGrid, Mailchimp, Zoho and others. A custom selector will not show up, which is why a negative result here is a prompt to check, not a verdict.
DMARC — what to do when checks fail: Ties SPF and DKIM together and tells receivers how to treat failures. p=none monitors only, p=quarantine sends failures to spam, p=reject blocks them. Start at none with a rua= reporting address, read the reports, then tighten.

A reasonable starting DMARC record

Type:  TXT
Name:  _dmarc
Value: v=DMARC1; p=none; rua=mailto:you@yourdomain.com

p=none changes nothing about delivery — it only asks receivers to send you reports. That makes it safe to add today, and it starts the data collection you need before tightening the policy.

Is my domain data stored?

No. The lookup reads public DNS records and returns them. Nothing is logged or retained, and every record this tool reads is already publicly visible to anyone who queries DNS.

Records in order? The next constraint is usually warmup and mailbox rotation, which is what a sending platform handles. Our tool finder matches you to one, or check your copy with the spam word checker.