DMARC has been endorsed by a high umber of individuals and organisations that include:

The National Cyber Security Centre
"Widespread adoption of the DMARC protocol is essential to defend against targeted cyber threats."

Ed Tucker, Head of Cyber-Security at HMRC
“I've been a DMARC supporter for over three years now,”

UK Government
The UK government have mandated that all government agencies need to be DMARC protected. 

US Department of Homeland Security
"
On Monday October 16, the Assistant Secretary for Cybersecurity and Communication for the U.S. Department of Homeland Security announced that the Acting DHS Secretary signed Binding Operational Directive (BOD) 18-01 requiring all federal agencies to implement the DMARC protocol across all federal email domains within 90 days. Agencies have until January 16th to adopt DMARC and be at  a minimum of policy level “none."

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