Email Security

The Top 9 Alternatives To Microsoft Exchange Online Protection

The top 10 alternatives to Microsoft Defender For Office 365 for email security, covering features, reporting, and admin controls.

The Top 9 Alternatives To Microsoft Exchange Online Protection include:
  • 1. Abnormal Security
  • 2. Agari
  • 3. Avanan
  • 4. Barracuda Email Protection
  • 5. Inky
  • 7. Mimecast
  • 8. Microsoft Defender For O365
  • 9. Proofpoint Essentials

Microsoft 365 is currently the most popular cloud email platform for organizations globally. And it’s easy to see why; it’s a powerful tool for collaboration, productivity, and communication. 

Unfortunately, because the tool so widely used, this makes it a prime channel for cybercriminals to target users with email threats such as phishing, malware and ransomware. 

To prevent this, Microsoft offers an email security solution designed to work natively with Microsoft 365: Exchange Online Protection (EOP). EOP is a cloud-based email filtering service that’s designed to protect users against spam, malware and other known email threats. This solution is included as standard in all Microsoft 365 organizations using Exchange Online mailboxes. 

EOP filters all incoming email messages to look for malware and checking against pre-set policy filtering rules. EOP also enables content filtering, looking for signs of spam, phishing or spoofing, and moving suspicious emails into a quarantine or junk folder. 

While EOP provides a good basic level of protection against known malware attacks, where it falls short is on protecting against sophisticated zero-day malware delivered via email, or sophisticated social engineering attempts that exploit the email channel to trick users. For these threats, many organizations will wish to look for an alternative email security solution to secure Microsoft 365 users. 

In this guide, we’ll look at the top ten alternatives to Microsoft Exchange Online Protection, based on features, reporting, and admin controls. We’ll cover a range of solutions, including secure email gateways, cloud email security solutions and outbound email security solutions. 

Abnormal Security Logo

Abnormal Security is a cloud-based email security solution that uses machine learning algorithms inside the email inbox to catch sophisticated email threats such as phishing attempts and ransomware. Abnormal was founded in 2018 and is headquartered in San Francisco.

The solution works by creating a baseline of your organization’s typical communication patterns and using this to identify any suspected malicious activity­––allowing admins to determine ­what happens with suspicious email messages.

Abnormal analyzes over 45,000 unique email signals to identify malicious email content. These signals include email content, time of sending, location of the sender and more. This provides a much higher degree of protection over scanning email messages based on known or unknown malware hashes. Abnormal provides granular admin controls for governing what happens with suspicious email messages and provides comprehensive reporting.

Abnormal Security is a good choice for organizations using Microsoft 365. It integrates with M365 using API, connecting in minutes and onboarding users with Microsoft’s Azure Active Directory system.

Users praise this service for its high level of accuracy and quick deployment. We recommend this solution for mid-sized or large organizations looking for strong protection against sophisticated phishing and business email compromise attacks.

Agari Logo

Agari is a cloud-based email security solution that uses artificial intelligence and machine learning systems to catch sophisticated phishing attacks, account compromise attempts, and advanced malware at the inbox layer. Agari also offers an advanced DMARC solution, used by large enterprises such as Apple. Agari is headquartered in Foster City, California and was recently acquired by Help Systems.

 Agari’s Phishing Defense solution works by using artificial intelligence to scan users’ typical email communication habits and behavioral patterns, and then uses this data to rate the likelihood of an email being suspicious. This is an effective way to filter out spear phishing attempts and business email compromise attacks.

The platform also enables employees to report emails that they believe could be a phishing attack. Agari’s platform then scans these reported threats, determines if emails are genuinely suspicious, and passes the reported emails onto admins for human review. Agari is a strong choice for Microsoft 365 users, integrating easily via API connection and Azure active directory.

Users praise Agari for its powerful phishing detection and modern, intuitive admin console. We recommend this solution for mid-sized to large organizations looking for protection against sophisticated social engineering, account compromise and phishing attacks in Microsoft 365.

Avanan Logo

Avanan is a popular email security solution offering a comprehensive email security platform for Microsoft 365. It provides anti-phishing, anti-malware and account take over protection, with inbound, outbound and internal email scanning. Avanan is headquartered in New York and was recently acquired by leading cybersecurity solutions provider Check Point Software Technologies.

Avanan uses machine learning algorithms to understand and learn unique email communication patterns within an organization, and by analyzing unique email attributes to scan for common signs of malicious activity and malware. This allows it to catch new and sophisticated email threats, otherwise missed by static email protection technologies.

Avanan also provides protection for other malicious content in Microsoft 365­­––including protecting against phishing attacks and malicious content in Microsoft Teams, OneDrive and SharePoint. This includes data loss prevention, malware scanning, URL sandboxing, suspicious login detection and automated remediation, such as removal of suspicious files.

Avanan is a popular email security solution. Users praise the service for its ease of deployment and intuitive admin console. The platform is a strong choice for organizations looking for a comprehensive security platform—especially since its acquisition by Check Point, as the service is now integrated with their wider security stack.

We recommend Avanan for organizations looking for comprehensive protection in Microsoft 365 across email, Teams, OneDrive and SharePoint.

Barracuda Logo

Barracuda Email Protection is a comprehensive email security solution, that provides multi-layered email security to protect organizations against sophisticated email threats—from basic spam and malware to business email compromise and account takeover attacks. Barracuda is headquartered in Campbell, California and was recently acquired by KKR from Thoma Brava.

Barracuda Email Protection combines a secure email gateway service with post-delivery protection inside the email inbox, as well as  instant remediation, enabling comprehensive protection against email security threats.

The first layer of Barracuda’s security is at the email gateway; the solution scans inbound emails to prevent spam, ransomware, and phishing attacks. The second layer is inside the inbox itself, with machine learning algorithms used to detect email threats after they have been delivered to users, looking at indicators of account compromise and signs of malicious activity within emails themselves.

Finally, Barracuda provides automated incident response, deleting any suspicious emails detected by the system in minutes, according to admin policies. In addition, Barracuda also offers email encryption, archiving, outbound email security and DMARC solutions.

Barracuda users praise the solution for its effective protection against both spam and malware and sophisticated phishing attacks. We recommend this solution for small and mid-sized enterprises looking for a multi-layered email security solution.

Inky logo

Inky is a cloud-based email security solution designed to prevent sophisticated phishing and malware attacks in cloud-based email platforms—‚such as Microsoft 365 and Google Workspace—using a combination of machine learning detection engines and warning banners. Inky is headquartered in College Park, Maryland and was founded in 2008.

Inky uses machine learning systems to instantly scan inbound, internal, and outbound email messages for signs of phishing attempts, impersonation attacks or malware. The platform displays customizable banners to users on all email messages, indicating whether they are safe, potentially malicious, or harmful. Admins can choose to send email messages straight to quarantine or allow users to make the judgement as to whether the email is harmful or not.

Inky works on all devices and across all email platforms, providing comprehensive protection that’s ideal for email users in a remote organization, or with a high number of users using personal devices for emails. The platform is quick and straightforward to deploy into Microsoft 365 and is a strong extra layer of email protection to compliment EOP or a secure email gateway solution.

Users praise this service for its modern admin console, comprehensive reporting, and easily digestible email banners for end users. We recommend this solution for organizations looking for an intuitive email security platform in the cloud, that’s specifically catered to preventing phishing attacks and impersonation attempts.


IRONSCALES is a comprehensive cloud-based email security solution that provides a powerful layer of protection against phishing, account compromise and malware for inbound, outbound and internal email messages. Unlike a traditional SEG, IRONSCALES provides protection at the inbox-layer with machine learning systems scanning and rewriting email messages. IRONSCALES is headquartered in Atlanta, Georgia and was founded in 2013.

IRONSCALES uses highly effective machine learning algorithms to detect signifiers of suspicious activity in email messages, including detecting when a sender is using a similar email address to one a recipient has communicated in the past but with small differences, and displays a warning banner to users. This is a common tactic used in phishing and impersonation attempts via email.

IRONSCALES provides powerful malware and anti-virus protection, leveraging multiple anti-virus engines to scan email content, attachments, and URLs. This protection covers email, Teams, and SharePoint files, providing comprehensive protection for Microsoft 365 applications. In addition, users can report suspicious emails to admins, who can analyze these emails, leverage advanced reporting capabilities and configure policies from a modern admin console.

Users praise IROSNCALES for its comprehensive email protection and well-developed feature set. We recommend this solution as a strong email protection platform for small, mid-sized and large organizations—particularly those that are looking to prevent sophisticated phishing and malware attacks.

Mimecast Logo

Mimecast is a market-leading email security and cyber resilience provider, known globally for its comprehensive secure email gateway solution for enterprise networks. Mimecast provides powerful email filtering to prevent spam, malware, and phishing attacks to over 39,000 organizations, with over 20,000 using Microsoft 365. Mimecast was founded in 2003, and is headquartered in London, United Kingdom.

Mimecast provides an advanced email security platform, with malicious URL protection, real-time URL scanning and malicious attachment protection, leveraging multiple anti-virus engines. Mimecast secures against internal inbox threats with real-time post-delivery scanning of inbound email messages to detect header anomalies and domain impersonation attempts. Mimecast also provides advanced browser isolation, opening email links in a secure web page to prevent ransomware attacks and malicious downloads delivered via email.

Mimecast provides comprehensive reporting and granular policy configurations in a modern, cloud-based admin console. Deployment is straightforward and the gateway is suited for Microsoft 365 users with a range of API-based integrations. Mimecast’s email filtering incudes a 100% anti-virus and 99.% anti-spam SLA.

Mimecast is a popular service for enterprise users, who praise the service for its powerful threat detection features, and granular policy management. This platform provides powerful protection and an advanced feature set, which we would recommend for mid-sized to large organizations.

Microsoft logo

Microsoft Defender For O365 is Microsoft’s own email security solution, that’s designed to work alongside the default Exchange Online Protection security as an extra layer of defense against malicious email messages, business email compromise, harmful links and malicious attachments. Microsoft Defender for O365 is available as part of Microsoft’s Office 365 E5 license, or available as a standalone module.

Defender for O365 allows admins to configure granular and flexible policies to prevent predefined email threats. This includes Safe Attachments, which checks all emails for malicious attachment content, Safe Links, which provides real-time URL scanning to prevent harmful URLs and Anti-Phishing Detection, which detects and automatically removes impersonation attempts using machine learning models. Microsoft’s Safe Attachments and Safe Links features also work across SharePoint, OneDrive and Microsoft Teams.

Defender for O365 also provides advanced reporting, displaying real-time threat insights, recommendations and alerting if any suspicious emails are detected. This is managed from the admin console, which also provides threat detection and response capabilities. These include threat intelligence, a real-time threat detection dashboard with automated investigation and response capabilities, and an attack simulation module.

Defender for O365 is a strong choice for organizations that want to keep their email security controls native to Microsoft 365. It’s very easy to set up and running, and continuous improvements are being made to the service’s threat detection capabilities. We recommend this solution for small and mid-sized organizations looking for an extra layer of email threat protection.

Proofpoint Logo

Proofpoint Essentials is an SMB-focused suite of email security solutions, including a leading secure email gateway, email archiving, encryption, and business continuity delivered in a single admin console. Proofpoint is the world’s leading email security provider with annual revenues of over $1bn USD.

Proofpoint collects and analyzes more than 100 billion data points a day from more than 100 million email boxes, 200 million social-media accounts, and 7 million mobile apps. Proofpoint secures more than 50% of the Fortune 100, the top 5 banks globally and 7 of the top 10 global retailers.

Proofpoint Essentials provides powerful protection against sophisticated email threats, with URL scanning, attachment defense, spam detection and phishing detection. The admin console is modern and user-friendly, enabling granular and flexible policy configuration for filtering unwanted emails, and advanced reporting. Users can also access their own email quarantine to read blocked message, while being protected from malware. Our testing of the PPT Essentials system has found the system to be flexible and adept at filtering malicious and nuisance emails.

Proofpoint is a strong alternative to Microsoft Exchange Online Protection, providing a much higher level of email protection. The solution is easy to integrate with Office 365, leveraging Azure Active Directory to quickly onboard users. Users praise this service for its powerful email protection and advanced admin controls. We recommend this solution for small and mid-sized organizations looking for comprehensive email protection.

The Top Alternatives To Microsoft Exchange Online Protection