DocumentationExperience Cloud KCS

550 Rejected by Header Based Anti-spoofing Policy

Last update: August 18, 2026

Description description

Email bounces with Error: 550 Rejected by header based Anti-Spoofing policy

Resolution resolution

This error can happen if:

  • DKIM/SPF configuration is incomplete for the from domain in the sending email address.

https://experienceleague.adobe.com/docs/marketo/using/getting-started-with-marketo/setup/configure-protocols-for-marketo.html?lang=en

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