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Glossary Security

DMARC

DMARC is a DNS policy that tells receivers what to do with email that fails SPF and DKIM alignment, and where to send reports about it.

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In more detail

A message passes DMARC when SPF or DKIM succeeds and the authenticated domain matches the visible From domain. The policy p= is none, quarantine or reject, and rua= names the address for aggregate reports. Moving from none to reject in steps is the standard way to stop others spoofing your domain.

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DMARC Record Generator

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See also

  • Glossary SPF
    SPF (Sender Policy Framework) is a DNS record listing which servers may send email for a domain.
  • Glossary DKIM
    DKIM (DomainKeys Identified Mail) adds a digital signature to outgoing email that receivers verify with a public key published in DNS.
  • Glossary Phishing
    Phishing is a scam in which attackers pose as a trusted organisation or person, usually by email or text.
  • Guide How Email Authentication Works: SPF, DKIM and DMARC
    What SPF, DKIM and DMARC each check, what their DNS records look like.
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