Since June 2016, the Global Cyber Alliance (GCA) has been working to accelerate adoption of DMARC, an email security standard, by providing a set of easy-to-use tools and campaigns to drive deployment. This paper investigates and measures the economic benefit from that work. Having reviewed the available data, we have chosen to focus on Business Email Compromise (BEC) because it is a rapidly growing issue, with high direct losses, and relevant data is available for analysis from multiple sources. We derive a conservative minimum bar estimate for the loss avoidance tied to GCA’s initiatives and discuss the potential scale of other benefits gained from DMARC.