Abnormal AI

Abnormal AI is a cloud-native email security company founded in 2019 by Evan Reiser and Sanjay Jeyakumar, headquartered in San Francisco, California. The company focuses on protecting enterprise email environments from socially engineered attacks, including business email compromise (BEC), credential phishing, and account takeover.

Abnormal's platform uses behavioral AI to establish baselines of normal communication patterns across employees, vendors, and partners, then flags anomalies that indicate malicious activity. The product integrates with Microsoft 365 and Google Workspace via API, requiring no changes to mail routing. The company serves customers across financial services, healthcare, retail, and other sectors, and has disclosed relationships with large enterprises.

Abnormal raised a $210 million Series C round in May 2022 at a $4 billion valuation, led by Insight Partners, bringing total funding to approximately $284 million. Earlier rounds included a $50 million Series B in 2021 and a $24 million Series A in 2020. The company has grown headcount significantly since its founding and employs several hundred people as of 2024.