dns7 min readBy Website Auditor ResearchUpdated 2026-01-05

DMARC in Plain English

SPF, DKIM, DMARC. Three DNS records, one goal: stop other people from sending email as you. Here is what each one actually does.

SPF

SPF lists which IP addresses are allowed to send mail claiming to be from your domain. It's a TXT record. Wrong SPF equals bounced mail.

DKIM

DKIM is a cryptographic signature added to every outgoing message. Recipients verify it against a public key in your DNS. Wrong DKIM equals spam folder.

DMARC

DMARC ties SPF and DKIM together and tells recipients what to do when either fails. Start with p=none and reports, work up to p=reject.

Frequently asked questions

SPF and DMARC are the minimum. DKIM is required by more and more providers — Gmail requires it for bulk senders.

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