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Free SPF, DKIM and DMARC Checker

Check a domain's email authentication: SPF, DMARC, DKIM for common selectors, and MX records, with the problems that send mail to spam.

  • Free, no sign-up
  • Reads public pages only
  • Updated Oct 25, 2026

Try:

How to use the SPF, DKIM and DMARC checker

  1. 1

    Enter your domain

    The one you send email from.

  2. 2

    Read each record

    SPF, DMARC, DKIM and MX, passed or flagged.

  3. 3

    Fix before you send

    Especially before a launch announcement.

Why email authentication matters

Since 2024, Gmail and Yahoo require bulk senders to have SPF, DKIM and DMARC. Without them, launch emails and password resets land in spam or bounce.

SPF lists the servers allowed to send for your domain. DKIM signs each message with a key published in DNS. DMARC tells receivers what to do when a message fails, and where to send reports.

Questions

Which DKIM selectors are checked?

Common ones: google, selector1, selector2, k1, default, s1, s2, mail, resend, mandrill and more. Enter your own selector if it is different.

What DMARC policy should I use?

Start with p=none and reports, then move to quarantine and reject once all your senders pass.

Can I have two SPF records?

No. Two SPF records make SPF fail. Merge them into one.

What is the SPF 10 lookup limit?

SPF may trigger at most 10 DNS lookups through include, a, mx and redirect. Too many includes break it.

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