26 - 50 employees
Series A
Enterprise Software / SaaS

GreatHorn Company Overview

GreatHorn's mission is to redefine the email security industry to better protect organizations against advanced email threats like phishing, social engineering attacks, and zero-day malware. Our execution on this mission has driven triple-digit growth for three years in a row, and we’re poised to accelerate that growth in the coming year.

Led by cybersecurity veterans, we solve our customers’ email security struggles with leading-edge technology and a team of dedicated, clever people with a customer-first philosophy. We strictly adhere to (and are proud of) our “No A**holes” policy. If this sounds like a team you’d enjoy working with, we hope you’ll check out our career opportunities!

Read more about us in these features:

Jobs at GreatHorn



We’re a team of serial entrepreneurs and cybersecurity veterans, solving a massive problem in an enormous market, and we’re committed to the success of our customers and colleagues.

From the accuracy and ease of deployment of our product, to our community of customers and colleagues, “be better than expected” is our motto, and we live and celebrate it.

Our diverse backgrounds and collaborative, creative, passionate approach to problem solving means that we rally around a culture that values teamwork, attention to detail, hard work, and innovation.

Integrity, honesty, and follow-through are fundamental to who we are, and our commitment to uphold our values underscores everything we do. We believe strongly in diversity, and seek to recognize, develop and support talent from all backgrounds.


No A**holes
Ask Questions
Details Matter
Experiment, Then Iterate
Be A Team
Power Through
260 Charles St
Waltham, MA 02453


July 14, 2020
2020 Email Security Benchmark: How Organizations Are Responding to More Frequent and Sophisticated Phishing Attacks At GreatHorn, we have a 30,000-foot view of the email phishing threat landscape. That enables us to see hotspots like a recent spate of coronavirus-themed phishing emails hitting inboxes. That view isn’t enough to understand how phishing email attacks are […] The post 2020 Email Security Benchmark Report: Response Phishing Attacks appeared first on GreatHorn. ...
June 28, 2020
Times of change are also times of opportunity. This is true for most businesses, and it is also true for cyber criminals. We’ve written previously about how the good habits built up by people in your organization–opening urgent-seeming attachments, responding quickly with information requested by a supervisor–can turn into liabilities when an attacker puts them […] The post Phishing Attacks: How a COVID-19 Attack is Interconnected to Other Attacks appeared first on Great...
June 24, 2020
At some point, email, the world’s most widely used productivity tool, became the world’s biggest time-suck. Most people fight the tide by getting through their inbox as quickly as they can. Actions required to move an email from “inbox” to “archive” become rote, with employees responding to emails almost reflexively. After all, responding quickly to […] The post How to Detect Risky URLs in Your Email: Top 3 Things to Check appeared first on GreatHorn. ...
June 22, 2020
In most things in life, absolute certainty is rare. Decisions are made without perfect information, based on probabilities and risk assessment. Protecting your organization from email phishing attacks is no different, and yet most email security providers see the world in black-and-white terms of absolute certainty: they block the known bad and let everything else […] The post Beyond Known Bad: Historic Communications and Email Security appeared first on GreatHorn. ...
June 22, 2020
This is the fifth in our five-part series evaluating anti-phishing tools. To start at the beginning, read Automated phishing response tools: 4 things to consider” In previous blogs we highlighted the 4 things to consider when assessing automated phishing response tools. And, discussed in-depth, the following 3 aspects: Incident response: Email Threat Remediation: The Secret […] The post Discussing Corporate Maturity to Evaluate Security Vendors appeared first on GreatHorn. ...