New Test Results Find GreatHorn Superior to Microsoft Defender for Office 365

Testing conducted by The Tolly Group solidifies GreatHorn’s position as a cloud email security industry leader

WALTHAM, Mass., Nov. 23, 2020 – Today, GreatHorn published the results of a test conducted by The Tolly Group examining the capabilities of their product in comparison to those of Microsoft Defender for Office 365. The findings, detailed in the Cloud Email Security Platform vs. Microsoft Defender for Office 365 report, revealed that GreatHorn’s solution provides significantly more email security functionality and a more robust and feature-rich implementation, while also being easier to use.

“We’re delighted, but not surprised, to see such stellar results from the comparison test,” said GreatHorn’s CEO and Co-founder, Kevin O’Brien. “We trusted The Tolly Group to provide a fair and unbiased assessment of our product, and the conclusions drawn only further establish GreatHorn as the best-in-class option for premium email security.”

Ease of Use

The test results showed GreatHorn’s ease-of-use as a major advantage, lowering the total cost of ownership as no specialized training is needed and key features and functions can be accessed quickly by anyone without particular knowledge of the system. In comparison, Microsoft Defender’s offering features a hierarchical, multi-layered approach to navigation that is less intuitive and informational to users. Ease-of-use is critical, as it enables administrators to access information rapidly and remediate threats before operations can be compromised.

Policy Definition and Functionality

GreatHorn’s policy definition, the core feature of any email security system, adopts a universal method. A single policy can be defined to protect against all manners of email-borne attacks including phishing, attachments, malware and spam. By contrast, Microsoft Defender forces the administrator to define a separate policy for each threat type and could require customers to generate up to five times as many policies needed to provide the same level of protection as GreatHorn. GreatHorn also offers significant functionality not found in Microsoft’s product, such as sophisticated relationship analytics, account takeover protection and impersonation detection. GreatHorn demonstrated more insightful and effective analysis than Microsoft and presents all essential analysis in a single screen. Account Takeover Protection, a capability unique to GreatHorn, bestows an additional layer of security using biometrics for multi-factor authentication. Additionally, GreatHorn’s link sandboxing consists of four different levels, each affording another layer of protection.

Security Event Analysis

With Microsoft Defender, users must have existing knowledge of what path to take to navigate and analyze an event. GreatHorn’s dashboard leverages several different one-click paths to security events: All emails, Policies, and Quarantine. Whereas GreatHorn’s dashboard is concise but thorough and provides a range of resources to help analyze events, Microsoft’s dashboard provides high-level summaries of events but no details. Thanks to GreatHorn’s easily navigable policy definition method, attributes can also be easily searched for. GreatHorn also features flexible remediation options, providing up to nine options that can be applied to an entire group of messages using search criteria. In contrast, Microsoft remediation appears to be limited in this capacity, and only offers remediation options on a by-message basis.

“The results, which truly proved GreatHorn’s excellence, are a critical reminder to organizations looking for email security to perform due diligence and assess options against their company’s specific needs,” said Kevin Tolly, founder of The Tolly Group. “As hackers are constantly striving to devise new and sophisticated attacks, it’s important that your email security solution can keep up and allow your administrators to constantly be on top of emerging threats. GreatHorn’s offering has proven to be the frontrunner in this regard.”

To download a copy of the full GreatHorn Cloud Email Security Platform vs. Microsoft Defender for Office 365 report, please visit:

About GreatHorn

GreatHorn safeguards cloud email from advanced threats like impersonations, credential theft, malware, and social engineering attacks by protecting organizations before, during, and after an email attack. Through its proactive threat detection engine, end-user education, and robust remediation capabilities, GreatHorn frees security teams from time-consuming email security management to enable them to respond to genuine threats faster. More information is available at

About The Tolly Group

The Tolly Group strives to provide IT users and vendors alike with independent, objective, hands-on testing, benchmarking services and consulting designed to illuminate differences between strategic products/services and help IT buyers make informed technology decisions. In over two decades, Tolly has published hundreds of independent tests, technology articles, and opinion pieces in leading business and trade publications.

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