SPF record checker

Enter a domain to check its SPF record: we follow every include: and redirect= to count the DNS lookups it costs (more than 10 and receivers fail it), and flag duplicate records and weak endings like ?all or +all. DMARC and DKIM are checked too. Free, no signup.

Email DNS of 20 well-known domains

We ran this lookup on 20 domains on 26 October 2026. All but one publish DMARC at p=quarantine or p=reject; gmail.com itself stays at p=none. SPF lookup counts range from 0 to the full 10: github.com sits exactly at the limit, so one more mail tool added with include: would break its SPF.

What we check

• SPF (TXT v=spf1): exactly one record; at most 10 DNS lookups counting every nested include:, a, mx, exists: and redirect= (more is a permanent error, and SPF fails for all mail); an ending of ~all or -all, not ?all or +all.
• DMARC (TXT at _dmarc.domain): one record with a p= policy. p=none only monitors; spoofed mail is still delivered. A rua= address gets you daily reports of who sends as your domain. Gmail and Yahoo require DMARC from bulk senders since 2024.
• DKIM: keys live at selector._domainkey.domain and the selector name is only in signed mail headers, so DNS can't list them. We try 15 common ones (google for Google Workspace, selector1/selector2 for Microsoft 365, k1 for Mailchimp, s1/s2 for SendGrid...). Not found doesn't mean missing: check the s= tag in a DKIM-Signature header of a mail you sent.
• DNS basics: at least two nameservers, an A or AAAA record for the bare domain, and an optional CAA record that limits which certificate authorities may issue certificates.

Check domains from code

The same lookup runs over the Shotmint API, free with any key (500 checks a day, 0 credits): check a client list's email setup in a spreadsheet, or alert in Make, n8n or cron when someone's SPF crosses 10 lookups.

curl -s "https://shotmint.creasework.com/v1/check?type=dns&url=github.com" \
  -H "X-API-Key: YOUR_KEY"
# {"type":"dns", "credits_used":0, "domain":"github.com",
#  "records":{"A":[...], "MX":[{"exchange":"github-com.mail.protection.outlook.com","priority":0}], ...},
#  "email":{"mx":true, "spf":{"record":"v=spf1 ...", "lookups":10, "all":"~"},
#           "dmarc":{"policy":"quarantine", ...}, "dkim":[{"selector":"google", ...}]},
#  "issues":[{"level":"info", "area":"SPF", "text":"SPF uses 10 of the 10 DNS lookups allowed. ..."}]}

More free checks: SSL checker, is it down, redirect checker, HTTP header checker, website technology checker. And to see the site itself: a website screenshot.

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