Loading organizations...

§ Private Profile · 951 20th Street, #540. Denver, Colorado 80201
Cloud-native email security platform detecting and preventing phishing, BEC, malware, and ransomware for enterprises.
GreatHorn, headquartered in Waltham, Massachusetts, provides a robust cloud-native email security platform. This platform is expertly designed to detect and prevent advanced threats such as phishing, business email compromise, malware, and ransomware for enterprises. Leveraging machine learning and data science, it analyzes communication patterns to offer integrated threat detection, automated incident response, and user engagement, specifically protecting Office 365 and G Suite users. Co-founder and Chairman Kevin O’Brien, along with Director of Product Management Matt and VP of Operations Ann Sharon, lead the organization, which was founded in 2015 by security industry veterans. GreatHorn has successfully raised a total of $22.18 million in funding, with its last known round occurring approximately three years ago, operating on a venture-funded SaaS model. The company continuously emphasizes its proprietary dataset, built from analyzing hundreds of millions of threats, adapting to each organization's unique communication patterns.
GreatHorn has raised $21.0M across 3 funding rounds.
GreatHorn has raised $21.0M in total across 3 funding rounds.
GreatHorn is a cloud-native email security company that builds an integrated platform to protect enterprises from phishing, business email compromise, social engineering, and zero-day email threats. It serves organizations using cloud email services like Office 365 and G Suite, primarily targeting sectors such as finance and education. GreatHorn’s platform combines advanced machine learning threat detection, user engagement through contextual education, and incident response capabilities to reduce email-related risks and improve security team efficiency. The company has demonstrated growth momentum by raising over $22 million in funding and serving Global 2000 companies with rapid deployment and high-impact protection[1][2][6].
Founded in 2015 and headquartered in Waltham, Massachusetts, GreatHorn was created to address the limitations of legacy email security gateways that were not designed for cloud-first environments. The founders leveraged their expertise in cybersecurity and data science to build a platform that continuously adapts to each organization’s unique communication patterns, enabling precise detection of anomalous and malicious emails. Early traction came from enterprises seeking modern, cloud-native solutions that integrate threat detection with user education and automated incident response, setting GreatHorn apart in the evolving email security market[1][2][4].
GreatHorn rides the critical trend of cloud migration and the increasing sophistication of email-based cyber threats, such as spear phishing and business email compromise. As organizations shift to cloud email platforms, legacy security tools fall short, creating a market need for cloud-native, adaptive solutions. The timing is crucial given the rise in targeted email attacks and the growing regulatory and operational emphasis on cybersecurity risk management. GreatHorn influences the ecosystem by advancing email security from simple threat blocking to a risk management discipline that integrates technology with human factors, thereby reducing breach risks and improving organizational resilience[2][3][6].
Looking ahead, GreatHorn is positioned to expand its influence by deepening integrations with cloud platforms and security orchestration tools, enhancing AI-driven threat intelligence, and broadening its user engagement capabilities. Trends such as increased remote work, cloud adoption, and regulatory scrutiny on data breaches will likely drive demand for sophisticated, automated email security solutions. GreatHorn’s emphasis on layered protection and risk management suggests it will continue evolving as a critical player in securing cloud communications, potentially expanding into adjacent areas of enterprise security and threat response[2][3][6]. Its ability to reduce email risk by up to 99% as reported by customers underscores its growing impact in the cybersecurity landscape.
GreatHorn has raised $21.0M in total across 3 funding rounds.
GreatHorn's investors include RRE Ventures, Greg Dracon, Amasia, Andreessen Horowitz, FJ Labs, Foundry Group, Fuse, Red Tree Venture Capital, Uncork Capital, Xfund, Anna Patterson, Evan Cheng.
GreatHorn has raised $21.0M across 3 funding rounds. Most recently, it raised $13.0M Series B in June 2019.
| Date | Round | Lead Investors | Other Investors | Status |
|---|---|---|---|---|
| Jun 1, 2019 | $13M Series B | RRE Ventures, Greg Dracon | Amasia, Andreessen Horowitz, FJ Labs, Foundry Group, Ysplit, RED Tree Venture Capital, Uncork Capital, Xfund, Anna Patterson, Evan Cheng, Patrick S. Chung, Techstars, V1.VC | Announced |
| Jun 1, 2017 | $6M Series A | Greg Dracon, ARI N. | Amasia, Andreessen Horowitz, FJ Labs, Foundry Group, Ysplit, RED Tree Venture Capital, RRE Ventures, Uncork Capital, Xfund, Anna Patterson, Evan Cheng, Patrick S. Chung, FF Venture Capital, Softtech Ventures | Announced |
| Mar 1, 2016 | $2M Seed | Uncork Capital, John Frankel | Amasia, Andreessen Horowitz, Collaborative Seed & Growth Partners, FJ Labs, Foundry Group, Ysplit, General Catalyst, Hyperplane Venture Capital, RED Tree Venture Capital, RRE Ventures, Sandbox Industries, TBD Angels, Xfund, Anna Patterson, Evan Cheng, Patrick S. Chung, Walt Winshall, Techstars, V1.VC, Zelkova Ventures | Announced |