DMARC Policy Overrides

When utilizing DMARC reporting, policy overrides might be a situation your company encounters. Essentially, a DMARC policy override occurs when an email recipient decides to override the policy that you have specified in your DMARC record.

For example, a policy override could happen when you have a DMARC policy of reject (p=reject) and your outbound email goes through a mailing list, which breaks both SPF and DKIM. In this instance, DMARC will fail; however, the receiver may decide to override your policy and accept the email. Some of the common DMARC overrides are described below:

• Forwarded: The initial message was relayed via a known forwarder, or local heurists identified the message as likely having been forwarded. There’s no expectation that authentication would pass.
• Local_policy: The mail recipient’s local policy exempted the message from being subjected to the domain owner’s requested policy action.
• Mailing_list: Local heuristics determined that the message arrived via a mailing list; therefore, authentication of the original message wasn’t expected to succeed.
• Other: Some policy exception not covered by the other entries in this list occurred. Additional detail can be found in the PolicyOverrideReason “comment” field.
• Sampled_out: The message was exempted from application of policy by the “pct” setting in the DMARC policy record.
• Trusted_forwarder: Message authentication failure was anticipated by other evidence linking the message to a locally-maintained list of known and trusted forwarders.