DKIM (DomainKeys Identified Mail)

Sitecheck Team

An email authentication method that uses digital signatures to verify message integrity.

DKIM (DomainKeys Identified Mail) adds a digital signature to outgoing emails using a private key held by the sending server. The receiving server verifies the signature against a public key published in a DNS TXT record, confirming the message has not been altered in transit.

Why it matters: DKIM proves email integrity and origin authenticity, improving deliverability and protecting recipients from tampered messages.

Quick tips:

  • Use a key length of at least 2048 bits.
  • Rotate DKIM keys periodically using different selectors to limit exposure if a key is compromised.
  • Implement alongside SPF and DMARC for full email authentication coverage.

See also: SPF, DMARC, DNS TXT Record.