AI Security

Tessian

AI email security preventing human error and data loss

7.5/10

Overview

AI-powered email security platform (now part of Proofpoint) focused on preventing human error — misdirected emails, data exfiltration, and advanced phishing. Uses machine learning to understand employee communication patterns and catch mistakes before they become breaches.

Ehsan's Growth Verdict

7.5/10

The only tool that prevents employees from emailing sensitive data to the wrong person — a $4.4 million average breach cost that nobody budgets for

Best for: Regulated industries (legal, finance, healthcare) where accidental data exposure via email is a material risk

Key Features

✓AI phishing detection
✓Misdirected email prevention
✓Data loss prevention for email
✓Employee security coaching
✓O365 and Google Workspace integration

Pros

+ Catches misdirected emails — a problem no other tool addresses well
+ In-the-moment coaching changes employee behavior over time
+ Acquired by Proofpoint adds stability and integration depth

Cons

− Proofpoint acquisition means potential feature consolidation
− Email-only scope limits standalone value
− Pricing is high for the narrow use case

Pricing

Plan	Details
Defender	Custom per-mailbox pricing
Enforcer	Custom (DLP module)
Guardian	Custom (misdirected email prevention)
Full Platform	Typically $3-6/mailbox/mo

Best Use Cases

Preventing accidental data leaks via email

Advanced phishing prevention

Employee security behavior training

Ehsan's Growth Take

Tessian found a problem hiding in plain sight: 58% of employees have sent an email to the wrong person, according to their research. Firewalls and EDR do not catch your finance director accidentally sending salary data to a client with a similar name. Tessian does. The Proofpoint acquisition in 2024 is a double-edged sword — it brings enterprise distribution but risks the product becoming a feature inside a larger bundle. If you are a Proofpoint customer, Tessian integration is a no-brainer. If not, evaluate whether the standalone misdirected email protection justifies the per-mailbox cost for your organization.

Ehsan Jahandarpour

AI Growth Strategist & Fractional CMO

Forbes Top 20 Growth Hacker · TEDx Speaker · 716 Academic Citations · Ex-Microsoft · CMO at FirstWave (ASX:FCT) · Forbes Communications Council

Frequently Asked Questions

What is Tessian?

How much does Tessian cost?

Tessian uses a subscription pricing model. Defender: Custom per-mailbox pricing. Guardian: Custom (misdirected email prevention). Enforcer: Custom (DLP module). Full Platform: Typically $3-6/mailbox/mo.

Is Tessian worth it in 2026?

Tessian scores 7.5/10 in our expert review. The only tool that prevents employees from emailing sensitive data to the wrong person — a $4.4 million average breach cost that nobody budgets for. Regulated industries (legal, finance, healthcare) where accidental data exposure via email is a material risk.

What are the alternatives to Tessian?

Alternatives depend on your specific needs. Compare Tessian with other tools in the security category using our comparison tool.

What are the pros and cons of Tessian?

Key pros: Catches misdirected emails — a problem no other tool addresses well, In-the-moment coaching changes employee behavior over time, Acquired by Proofpoint adds stability and integration depth. Key cons: Proofpoint acquisition means potential feature consolidation, Email-only scope limits standalone value, Pricing is high for the narrow use case.