Email authentication
Email authentication
Email Marketing
Email authentication is a set of DNS records (SPF, DKIM and DMARC) that prove an email really comes from the domain in its From address.
What is Email authentication?
Anyone can type your domain into a From line. Authentication lets inbox providers check it.
- SPF lists the servers allowed to send for your domain.
- DKIM signs each email so changes and forgeries can be detected.
- DMARC tells providers what to do when a message fails and sends you reports.
It's required now. Google and Yahoo ask bulk senders for SPF, DKIM and DMARC, and Microsoft's Outlook rules for senders of more than 5,000 emails a day took effect on May 5, 2025.
Example
A store adds the SPF, DKIM and DMARC records its ESP generates for mail.yourbrand.com, then clicks Check until all three pass.
Why Email authentication Matters
Unauthenticated marketing email is filtered or rejected by the biggest inbox providers.
Email authentication FAQ
Do I need SPF, DKIM and DMARC?
Yes. Google and Yahoo expect SPF and DKIM to pass and a DMARC record to be published for bulk senders.
Who adds email authentication records?
Whoever manages your DNS (Cloudflare, GoDaddy, Shopify domains and so on). Your ESP gives you the exact values.
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