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Email deliverability checker: SPF, DKIM and DMARC

Check whether a domain's email is set up to reach the inbox. We read its SPF, DMARC, DKIM and MX records from public DNS, count SPF's DNS lookups against the limit of 10, and explain every problem with a plain-English fix.

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How to use the Email Deliverability Checker

  1. 1Enter the domain you send email from (or paste an email address).
  2. 2Read the checks: each one is good, worth improving or a problem to fix, with the exact change to make.
  3. 3Compare the SPF, DMARC and DKIM records shown with what your email provider asks for.
  4. 4Make the changes in your DNS settings, wait a few minutes and check again.

Frequently asked questions

What do SPF, DKIM and DMARC do?

SPF lists the servers allowed to send email for your domain, DKIM signs each email so receivers can verify it wasn't changed, and DMARC tells receivers what to do when a message fails those checks and where to send reports.

Do I need DMARC to send email to Gmail?

Since 2024, Gmail and Yahoo require SPF, DKIM and a DMARC record from anyone sending more than about 5,000 messages a day, and they recommend all three for every sender.

Why does it say no DKIM key was found when DKIM works?

DKIM keys live under a selector name that can't be listed from outside. We try the common ones (google, selector1, selector2, k1, default, zoho and others). Your provider may use a different one.

What is the SPF 10 DNS lookup limit?

SPF may trigger at most 10 DNS lookups (include, a, mx, exists, redirect), including those inside included records. Past that, receivers treat SPF as a permanent error and it fails.

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