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About
Tessian AI Email Guard is an enterprise-grade, AI-driven email security platform that was acquired by Proofpoint, becoming a core part of Proofpoint's Adaptive Email DLP and Core Email Protection API offerings. Originally developed as a leader in using advanced AI for email security, Tessian's technology specializes in detecting and preventing threats that traditional rule-based systems miss — including misdirected emails, data exfiltration via email, phishing, and business email compromise. The platform leverages behavioral AI and machine learning models trained on historical communication patterns to understand how employees normally communicate. This allows it to identify anomalies and alert users or block messages in real time when sensitive data may be at risk or an impersonation attempt is detected. Key capabilities include Adaptive Email DLP (preventing accidental and intentional data loss over email), Account Takeover Protection (detecting and responding to compromised accounts), Email Fraud Defense (protecting brand reputation and blocking domain spoofing), and insider threat visibility. It integrates with existing email infrastructure via API or gateway deployment, making it suitable for Microsoft 365 and Google Workspace environments. Tessian/Proofpoint's solution is designed for enterprise security and compliance teams who need robust, low-friction protection without burdening end users with excessive prompts. It is especially valuable for organizations in regulated industries such as finance, legal, and healthcare where data governance and audit trails are critical.
Key Features
- Adaptive Email DLP: Prevents accidental and intentional data loss by detecting sensitive content and misdirected emails before they are sent.
- Account Takeover Protection: Detects, investigates, and responds to compromised email accounts using behavioral AI to identify anomalous activity.
- Email Fraud Defense: Protects brand reputation and prevents domain spoofing, business email compromise (BEC), and impersonation attacks.
- Behavioral AI Engine: Learns individual communication patterns to surface anomalies without relying on rigid rules, reducing false positives.
- API & Gateway Deployment: Integrates seamlessly with Microsoft 365 and Google Workspace via API or inline gateway without disrupting existing workflows.
Use Cases
- A financial services firm uses Tessian Adaptive Email DLP to automatically detect and block emails containing sensitive client data sent to wrong recipients.
- A legal team deploys Tessian to monitor outbound emails for confidential case documents and receive alerts when unusual sharing patterns are detected.
- An enterprise IT security team uses account takeover protection to identify and respond to compromised employee email accounts exhibiting abnormal behavior.
- A compliance officer leverages email data governance features to maintain audit logs of sensitive communications for regulatory reporting.
- A healthcare organization integrates Tessian with Microsoft 365 to prevent PHI from being accidentally emailed to external parties, ensuring HIPAA compliance.
Pros
- Minimal user friction: AI-driven detection reduces the need for constant user prompts, keeping security effective without hampering productivity.
- Comprehensive email threat coverage: Addresses a wide attack surface including outbound data loss, inbound phishing, account takeover, and insider threats in a single platform.
- Seamless enterprise integration: API-first architecture allows deployment alongside existing Microsoft 365 or Google Workspace setups with minimal configuration.
Cons
- Enterprise-only pricing: No self-serve or SMB tier; the platform is priced and scoped for large organizations with dedicated security teams.
- Brand transition complexity: Tessian is now folded into Proofpoint, which may create confusion for customers navigating product names, contracts, and support channels.
Frequently Asked Questions
What happened to Tessian?
Tessian was acquired by Proofpoint and its technology has been integrated into Proofpoint's Core Email Protection API and Adaptive Email DLP products.
How does Tessian detect misdirected emails?
Tessian's AI learns each user's communication patterns and flags emails sent to unintended recipients in real time, prompting users to review before sending.
Does Tessian/Proofpoint work with Microsoft 365 and Google Workspace?
Yes, the platform integrates with both Microsoft 365 and Google Workspace via API or gateway deployment, requiring no additional email routing changes.
What types of threats does Tessian protect against?
Tessian protects against outbound data loss, misdirected emails, phishing, business email compromise (BEC), account takeovers, and insider threats.
Is Tessian suitable for regulated industries?
Yes, it is widely used in finance, legal, healthcare, and other regulated industries where email data governance, audit trails, and compliance are critical requirements.
