Abnormal Security Review 2026

Abnormal Security revolutionizes email protection with behavioral AI that detects sophisticated threats like business email compromise, account takeover, and vendor fraud that bypass traditional signature-based gateways. By analyzing thousands of signals per message and learning normal communication patterns, it catches socially engineered attacks that contain no malicious payloads.

Abnormal Security is a cloud-native email security platform that leverages behavioral AI to protect organizations against the full spectrum of email-based attacks, including business email compromise (BEC), phishing, malware, ransomware, social engineering, and graymail. Founded in 2018 by CEO Evan Reiser and CTO Sanjay Jeyakumar, the San Francisco-based company has rapidly grown to achieve a $5.1 billion valuation as of its 2024 Series D funding round, backed by investors including Greylock Partners, Menlo Ventures, and CrowdStrike Falcon Fund.

Unlike traditional secure email gateways (SEGs) that rely on static rules, threat signatures, and known indicators of compromise, Abnormal takes a fundamentally different approach by using behavioral AI and machine learning to baseline normal communication patterns across an organization. The platform integrates directly via API with Microsoft 365 and Google Workspace, requiring no MX record changes, no gateway redirection, and no disruption to existing mail flow. This API-native architecture enables Abnormal to analyze both internal and external email communications, understanding organizational relationships, communication frequency, writing styles, authentication events, and supply chain interactions to build comprehensive behavioral profiles of every identity.