A study by 日本プルーフポイント株式会社 has revealed a significant gap between Japan and the US in the full enforcement of DMARC. While adoption among Japanese companies is progressing, marked differences were identified in the full enforcement rate and the operational status of government agencies.
日本プルーフポイント株式会社 surveyed DMARC implementation and full enforcement among Nikkei 225 companies, US Fortune 1000 companies, and government-related domains in Japan and the US in July 2026. The implementation rate among Nikkei 225 companies was 92%, up from 83% in August 2024, but only 43% had applied Reject or Quarantine, policies considered full enforcement. The Fortune 1000 recorded an implementation rate of 98% and a full enforcement rate of 83%, highlighting the difference in operational effectiveness. For government-related domains, Japan recorded 18% Reject, 61% None and 12% not implemented, while all domains surveyed in the US were reported to use Reject.
In terms of the background and challenges, adoption in Japan accelerated after Google and Yahoo in the US began requiring high-volume senders to implement DMARC from 2024 onward, and the standard specification was updated in 2026. In Japan's government agencies, responsibility for leading implementation has been described as unclear. In cases using None, nearly 10,000 impersonation emails per day were reportedly identified, while data was said to show a substantial reduction after a transition to Reject. By industry, full enforcement had progressed to 60% in financial services and insurance and 47% in manufacturing, while challenges remained in information and communications, where 60% used None, and real estate and goods rental, where the figure was 80%.