Advanced threat detection. Simple cloud connection.
Enterprise-class protection.

Free Risk Assessment

The greatest threats to your organization don’t come in clearly marked packages. 

GreatHorn sees what others miss – protecting you from both cleverly crafted phishing attacks and widespread traditional threats – from the point of delivery and throughout an email’s lifecycle.

Business Email Compromise

Service Impersonations


Account Takeover

Credential Theft



From missed executive impersonations and credential theft attempts to wasted hours spent reviewing quarantine folders and writing PowerShell scripts, email security can be a source of both frustration and risk.

Architected specifically for cloud email and designed to protect against both phishing attacks and traditional threats, GreatHorn connects directly and easily into your Office 365 or G Suite email environment, making it easy to safeguard your enterprise from advanced email threats – from the moment it hits your environment to the moment it’s deleted.

By automating detection, remediation, and incident response, GreatHorn gives you a straightforward, effective, and comprehensive email security solution.

No MX record changes. No Powershell scripts. No exposure. No exceptions.




Imposter Protection

Protect against executive / employee impersonations, look-alike domains, service impersonations, and business email compromise with GreatHorn’s advanced impersonation and spoofing detection.

Attachment Protection

Isolate both known, emerging, and suspected threats identified through multi-vector email analysis, proprietary community threat intelligence, and industry-leading threat intelligence.

Link Protection

Safeguard employees against credential theft attempts and malicious URLs with fully automated URL sandboxing, administrative tracking, and credential theft threat isolation.

Mailbox Protection

Empower users by providing them with meaningful context and the security tools they need to make better risk decisions and become intelligent, informed, and vital parts of your security posture.


Email threats don’t stop at the perimeter, and neither should your email security platform. With GreatHorn Email Security, protection means more than just detecting and quarantining threats at time of delivery. That’s why we provide tools for every stage of the email security lifecycle.

Adaptive Threat Detection

Identify and protect against both emerging and targeted threats using GreatHorn’s combination of advanced threat intelligence, deep relationship analytics, technical and social fingerprinting, spoofing detection, and anomaly identification.

Automated Threat Defense

Minimize manual intervention with configurable remediation actions – including in-context user training, policy reminders, link rewriting and preview, and quarantine – that can be adjusted for an organization’s risk tolerance and profile.

Post-Delivery Incident Response

Respond to incidents faster and eliminate PowerShell scripts with post-delivery threat removal (that’s still available weeks after initial delivery), multi-factor search capabilities, forensic analysis, and end-user reporting functionality.


Detecting threats before they reach your employees is just the first step in enterprise-class protection.

With GreatHorn, protection isn’t just about detection. Here are some of the other benefits our customers see:

Reduced Complexity
  • 5-minute implementation – No gateway to manage
  • No MX records to reroute
  • Uninterrupted email flow means no dependency on 3rd party for email deliverability
  • Visibility into both internal & external email
Minimal Manual Remediation
  • More effective, tunable threat detection
  • Fewer quarantined emails due to automated, customizable remediation actions
  • No more Powershell scripts with easy post-delivery email removal based on multi-vector search
Positive Impact on Business Operations
  • In-context user training reduces risk while educating employees
  • Context-driven policy reminders encourages business process adherence
  • Reduced use of quarantine minimizes disruption to business

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