Free tool
Email authentication checker.
Look up a domain's MX, SPF, DKIM, DMARC, and BIMI readiness in one pass. See the evidence, what passes, and what to fix.
Three records prove your mail is yours.
01
SPF
SPF lists the servers allowed to send mail for your domain. A receiver checks the sending server against that list and flags mail that comes from anywhere else.
02
DKIM
DKIM signs each email with a private key. The receiver fetches the matching public key from your DNS and confirms the email arrived unaltered.
03
DMARC
DMARC ties SPF and DKIM together. It tells receivers what to do when an email fails both, and sends you reports on who is sending mail as your domain.
Common questions
It looks up the DNS records that prove an email came from your domain: SPF, DKIM, and DMARC. Enter a domain and you get each record, whether it is configured, and what to change if it is not.
SPF lists the servers allowed to send mail for your domain. DKIM signs each email so receivers can confirm it arrived unaltered. DMARC tells receivers what to do when an email fails both checks, and reports back on who sends mail as you.
It verifies the public BIMI record, the effective DMARC enforcement policy, and safely decoded facts from the declared logo and mark certificate. It cannot prove that a real email aligned, that every receiver trusts the certificate, or that a provider will display the logo.
SPF and DKIM each cover one angle of forgery, and an email can pass one while failing the other. DMARC ties them together and sets the enforcement policy. Mailbox providers weigh all three when they decide inbox or spam.
Whoever sends your mail sets the selector. Open an email you sent, find the `DKIM-Signature` header, and read the `s=` value. Leave the field blank and this tool probes the selectors that common providers use.
No. Passing records get your mail evaluated; sender reputation, list hygiene, content, and engagement decide placement from there. Failing records hold mail back before any of that matters.
Recheck whenever you add a sending service, rotate a DKIM key, or move DNS providers. A quarterly pass catches records that a vendor change quietly broke.
Send from a domain that passes.
Samva walks you through SPF, DKIM, and DMARC on your own domain, then feeds bounces and complaints into suppression so your reputation holds as volume grows.