Editorial Guide

MX vs SPF vs DKIM

Compare mail routing, sender authorization, and message signing in one plain-English guide.

MX, SPF, and DKIM are often discussed together, but they solve different problems in email infrastructure.

MX records help route inbound mail, SPF helps declare which servers may send mail for a domain, and DKIM helps validate message integrity and signing.

What MX records do

MX records tell other mail servers where inbound mail for a domain should be delivered.

What SPF does

SPF publishes sender-authorization policy so receivers can evaluate whether a sending source is expected.

What DKIM does

DKIM uses cryptographic signing so receivers can verify that a message was signed by an authorized domain and was not altered in transit.

Practical takeaway

Use MX for routing checks, SPF for sender policy, and DKIM for message-signing validation. In practice, all three may matter during delivery troubleshooting.

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