Brief Overview

GreatHorn is a cybersecurity solution for cloud communication infrastructure, including email, collaboration, and chat tools.


260 Charles St
Ste. 300
Waltham, MA 02453
Tel: (855) 478 - 4676


Kevin O’Brien serves as CEO and Co-Founder.


GreatHorn was founded in 2015 by Kevin O’Brien and Raymond Wallace III. They are headquatered in Belmont, Massachusetts.

Key Competitors

Halon, HPE

Products and Services

GreatHorn offers products broken down into these three cateogories:
• Inbound Email Security - Comprehensive post-delivery protection against targeted email attacks, powered by machine learning and automated response capabilities.
• Messagin Security – Automated security operations and reporting for chat and collaboration platforms like Slack.
• GH Threat Platform – Automated threat detection and response for in-house communication systems.