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Email deliverability checker

Check the SPF, DKIM, DMARC, and MX records published for your domain. This tool is free and needs no account. DNS checks alone cannot establish inbox placement.

DNS record builder

If a check fails, build the record here and paste it into your DNS.

Who sends mail for this domain?
Unlisted senders
Paste into your DNS
Host@(domain root)
TypeTXT
Valuev=spf1 include:amazonses.com -all

What the tool checks

  • SPF: one TXT record at the root, valid syntax, and an ending of -all or ~all.
  • DMARC: a policy at _dmarc.<domain>, graded on enforcement (p=reject or p=quarantine) and reporting (rua=).
  • MX: the domain can receive replies, bounces, and reports.
  • DKIM: a signing key at your selector, or at the common selectors if you do not know it.

The checks query public DNS. The tool stores no results.

Before you change enforcement, read the DMARC policy guide. To test a send, follow the email API tutorial.

FAQ

What do SPF, DKIM, and DMARC do?

SPF lists which servers may send mail for your domain. DKIM signs each message so receivers can verify that it was not forged or altered. DMARC checks whether a passing SPF or DKIM result aligns with the visible From domain. DMARC also publishes a policy for failures and can request aggregate reports.

Why does this matter for AI agents?

An agent that sends email uses your domain's reputation. Check the domain's DNS setup before sending, then inspect delivery and bounce events. This tool checks published records. It cannot guarantee inbox placement or show whether a specific message passed authentication.

Why wasn't my DKIM key found?

DKIM keys are published at <selector>._domainkey.<domain>. Your sending provider chooses the selector name. Without a selector, the tool checks common ones (default, google, selector1, selector2, k1, s1, s2, amazonses). If your provider uses a custom selector, enter it in the selector field and run the checks again.

Is a warning a problem?

A warning flags a setting to review, such as SPF ending in ?all or DMARC at p=none. Monitoring mode can be intentional while you identify legitimate senders. Check actual authentication results and reports before tightening enforcement.

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