GreatHorn
GreatHorn's Overview
Greathorn is a cloud-native email security platform, acquired by Proofpoint in August 2022. It specializes in protecting organizations from advanced email threats such as phishing, business email compromise (BEC), impersonation, and credential theft. Greathorn's technology leverages artificial intelligence (AI) and machine learning to analyze email content and context, providing enhanced threat detection and response capabilities, particularly for cloud-based email systems like Microsoft 365 and Google Workspace. It is now integrated into Proofpoint's broader suite of cybersecurity solutions.
Where is GreatHorn's Headquarters?
HQ Function
Prior to its acquisition by Proofpoint, this location served as Greathorn's main office, housing its executive leadership, engineering, product development, sales, and marketing teams. Post-acquisition, the Greathorn team and technology are integrated into Proofpoint, which also maintains an office presence in Waltham at the same address.
Notable Features:
The office is situated in a modern commercial building, likely offering contemporary amenities, collaborative workspaces, and infrastructure suited for a technology company. Specific architectural highlights are characteristic of the broader office park.
Work Culture:
As an independent company, Greathorn fostered an innovative, agile, and collaborative work culture focused on solving complex cybersecurity challenges. This ethos is now carried forward within the relevant Proofpoint teams.
HQ Significance:
The Waltham location was strategically important due to its proximity to a rich talent pool from nearby universities and a vibrant ecosystem of technology companies, investors, and research institutions.
Values Reflected in HQ: The choice of a modern office in a prominent tech hub reflected Greathorn's commitment to innovation, cutting-edge technology, and attracting top talent in the cybersecurity field.
Location:
As part of Proofpoint, Greathorn's technology contributes to a global cybersecurity presence. Proofpoint serves tens of thousands of customers worldwide across various industries. The Greathorn email security capabilities are delivered globally through Proofpoint's cloud platform, supported by international sales, support, and threat intelligence operations.
Street Address:
200 Fifth Ave
City:
Waltham
State/Province:
MA
Country:
USA
GreatHorn's Global Presence
Buying Intent Signals for GreatHorn
Highperformr Signals uncover buying intent and give you clear insights to target the right accounts at the right time — helping your sales, marketing, and GTM teams close more deals, faster.
Executive Team of GreatHorn
As of April 2025, GreatHorn' leadership includes:
Investors of GreatHorn
GreatHorn has been backed by several prominent investors over the years, including:
Executive New Hires/Exits in the Last 12 Months
Following its acquisition by Proofpoint in August 2022, the Greathorn leadership team was integrated into Proofpoint. Key leadership roles for the Greathorn product line are now held by former Greathorn executives within Proofpoint's structure. The team structure largely stabilized post-integration. No major public announcements of new hires or exits specifically for this core product leadership group within Proofpoint have been noted in the immediate last 12 months (approx. May 2023-May 2024).
Technology (Tech Stack) used by GreatHorn
Discover the tools GreatHorn uses. Highperformr reveals the technologies powering your target accounts — helping your sales, marketing, and GTM teams prioritize smarter and close faster.
GreatHorn Email Formats and Examples
Historically, Greathorn likely used common email formats for technology companies, such as first.last@greathorn.com or first_initial_last@greathorn.com. While internal and official communications for the team now likely use @proofpoint.com domains, legacy @greathorn.com email addresses or product-specific contact points might still be encountered.
first.last@greathorn.com or firstinitiallast@greathorn.com
Format
jane.doe@greathorn.com or jdoe@greathorn.com
Example
70%
Success rate
News and media
Proofpoint Newsroom • August 29, 2022
Proofpoint Signs Definitive Agreement to Acquire GreatHorn
Proofpoint, Inc., a leading cybersecurity and compliance company, announced it signed a definitive agreement to acquire GreatHorn, Inc. This acquisition was aimed at enhancing Proofpoint's advanced threat protection platform with GreatHorn's cloud-native email security capabilities....more
Proofpoint Newsroom • February 7, 2024
Proofpoint: 80 Percent of Organizations Expect to Be Hit by a Successful Email Attack in 2024
A Proofpoint report highlighted the persistent and evolving threat of email-based attacks, including phishing and Business Email Compromise (BEC). This underscores the ongoing importance of advanced email security solutions, such as the technologies developed by Greathorn and now integrated into Proofpoint's comprehensive threat protection offerings, to defend organizations worldwide....more
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