Interoperability Issues Between DMARC and Indirect Email Flows
DMARC introduces a mechanism for expressing domain-level policies and preferences for message validation, disposition, and reporting. The DMARC mechanism can encounter interoperability issues when messages originate from third party sources, are modified in transit, or are forwarded enroute to their final destination. Collectively these email flows are referred to as indirect email flows. This document describes interoperability issues between DMARC and indirect email flows. Possible methods for addressing interoperability issues are presented.