Check MX, SPF, DKIM and DMARC
Enter a domain to view its MX, SPF and DMARC records, discovered DKIM selectors and basic configuration findings.
How to run the check
- Enter a domain and select “Check”.
- Review MX, SPF, DMARC and automatically discovered DKIM selectors.
- Change one record at a time at your DNS provider and allow for DNS cache propagation.
How to interpret the result
MX points incoming mail to a server, SPF lists authorised senders, DKIM publishes a signing key, and DMARC defines validation and reporting policy.
Limitation: valid records do not guarantee inbox placement. PTR/HELO alignment, IP and domain reputation, message content and the receiving provider’s policy also matter.
Frequently asked questions
Why are MX records needed?
MX tells sending servers where to deliver mail. Without MX delivery usually fails.
What are SPF and DMARC?
SPF lists authorised sending hosts. DMARC sets a policy (p=none/quarantine/reject) based on SPF/DKIM and instructs receivers what to do if a message fails.
How do I check DKIM?
DKIM keys are published at <selector>._domainkey.<domain>. Use auto-scan for typical selectors (selector1, selector2, default, s1, s2 …) or enter a selector manually.
What else matters for deliverability?
Recommended: PTR (reverse DNS) for MX hosts, A/AAAA present on MX, DMARC policy ≥ quarantine, ≤10 DNS look-ups in SPF, MTA-STS & TLS-RPT, DNSSEC, matching HELO ↔ PTR, TLS check on port 25.
Need help fixing email DNS?
- Include the domain and checker result
- Tell us which email provider you use
- Configuration and auditing are separate tasks
