Four checks behind every inbox placement
The same authentication records mailbox providers check before deciding spam or inbox.
MX
Confirms mail servers are configured to receive email for this domain.
SPF
Checks which servers are authorized to send mail as this domain.
DKIM
Looks for a cryptographic signing record under common selector names.
DMARC
Reports the policy for handling mail that fails authentication.
Email deliverability — common questions
Need SPF, DKIM or DMARC configured, not just checked? Our specialists can set it up correctly.
SPF (Sender Policy Framework) lists which mail servers are allowed to send email for your domain. Without it, receiving servers can't verify your mail is legitimate, which hurts deliverability.
DKIM adds a cryptographic signature to outgoing mail, published under a specific "selector" name chosen by your mail provider. There's no way to discover an arbitrary selector, so this tool checks common ones used by major providers — not finding a record doesn't mean DKIM is missing.
DMARC tells receiving mail servers what to do with email that fails SPF or DKIM checks. A policy of "none" only monitors; "quarantine" sends suspicious mail to spam; "reject" blocks it outright.
SPF and DMARC help, but spam placement also depends on sender reputation, content, DKIM signing and recipient engagement. Correct configuration is necessary but not always sufficient. Our email deliverability specialist service covers the full picture.
Yes, completely free with no signup. There's a small rate limit per visitor to keep the service fast for everyone.
Need SPF, DKIM or DMARC configured correctly?
Our email deliverability specialists set this up right the first time — 24/7, no long-term contract required.