SPF, DKIM, DMARC: Email Authentication Explained
Complete guide to email authentication: SPF records, DKIM signing, DMARC policies, and how they prevent email spoofing.
The Three Layers
- SPF: Lists which servers can send email for your domain.
v=spf1 include:_spf.google.com ~all - DKIM: Cryptographically signs each email so receivers can verify it was not modified
- DMARC: Policy that tells receivers what to do if SPF/DKIM fail: none, quarantine, or reject
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