The email security market in 2026 is shaped by the Q2 2025 Forrester Wave, which positioned Proofpoint and Abnormal AI as Leaders while recognizing the shift from gateway-based filtering to API-integrated, AI-powered detection. Proofpoint’s acquisition of Hornetsecurity closed in December 2025, extending its reach into the European MSP and SMB market. Meanwhile, attackers are shifting to multi-channel campaigns spanning email, voice, SMS, file-sharing platforms, and collaboration tools, forcing email security vendors to expand beyond the inbox.
How We Evaluated
We assessed phishing detection accuracy against credential harvesting, spear phishing, and polymorphic attacks. BEC protection mattered, including detection of business email compromise, impersonation, and invoice fraud. AI capabilities like behavioral analysis, natural language understanding, and adaptive detection played a major role. Integration with Microsoft 365, Google Workspace, SIEM/SOAR, and collaboration platforms counted. Response capabilities including automated remediation, post-delivery clawback, and incident investigation factored in, along with multi-channel coverage beyond email into Teams, Slack, file-sharing, and SMS.
1. Proofpoint Email Protection
Score: 95/100
Proofpoint leads the 2025 Forrester Wave with the highest marks in malware detection, URL detection, and sandboxing. The Hornetsecurity acquisition closed in December 2025, adding AI-powered Microsoft 365 security for MSPs and SMBs in Europe and expanding Proofpoint’s addressable market beyond enterprise.
Forrester scores were highest in malware detection, URL analysis, and sandboxing. The Nexus AI engine combines behavioral, language, and relationship analysis. The Hornetsecurity acquisition extends reach to MSPs and the European SMB market. Targeted Attack Protection includes URL rewriting and sandboxed link analysis. Supplier threat intelligence identifies compromised vendor accounts. The Human Risk Management platform quantifies individual user risk for targeted training.
Best for: Large enterprises requiring the broadest email threat detection with supplier compromise protection and human risk management
2. Abnormal AI
Score: 94/100
Abnormal AI achieved the highest Strategy score in the 2025 Forrester Wave and scored a perfect 5.0 in malicious message detection. The API-first, AI-native approach represents the clearest alternative to traditional gateway-based email security, using behavioral AI to detect attacks that bypass content-based filters.
A perfect 5.0 score in malicious message detection came from the Forrester Wave 2025. API-native integration requires no MX record changes or mail routing. Behavioral AI builds baseline profiles of every sender, recipient, and communication pattern. Multi-channel protection extends to Slack, Teams, and Zoom. The company reported a 350% year-over-year surge in attacks using compromised file-sharing tools in 2025. Automated remediation includes post-delivery message clawback.
Best for: Organizations wanting AI-native email security that detects sophisticated social engineering and BEC attacks that evade content-based filters
3. Microsoft Defender for Office 365
Score: 91/100
Microsoft’s built-in email security for Microsoft 365 continues to improve, with Copilot for Security integration adding AI-powered investigation and automated remediation. For organizations on E5 licensing, the cost-inclusion argument is compelling, though many enterprises still layer third-party solutions on top.
Native Microsoft 365 integration means zero deployment friction. Copilot for Security provides AI-powered email threat investigation. Safe Links and Safe Attachments use sandboxed detonation. Attack Simulation Training raises phishing awareness. Automated Investigation and Response handles automated remediation. Inclusion in Microsoft E5 provides significant cost advantage.
Best for: Microsoft 365 organizations on E5 licensing wanting built-in email security without additional vendor costs
4. Mimecast Email Security
Score: 89/100
Mimecast provides comprehensive email security with strong archiving, continuity, and compliance capabilities alongside threat protection. The platform scored as a Strong Performer in the 2025 Forrester Wave and differentiates with email continuity guarantees.
The comprehensive platform covers threat protection, archiving, continuity, and compliance. Strong BEC detection includes impersonation protection and DMARC management. Email Continuity ensures access during Microsoft 365 or Google Workspace outages. Brand protection and DMARC enforcement are included. Awareness training integrates with threat telemetry. Coverage spans both mid-market and enterprise.
Best for: Organizations wanting comprehensive email security combined with archiving, continuity, and compliance in a single platform
5. Cloudflare Area 1
Score: 87/100
Cloudflare Area 1, acquired in 2022, provides preemptive email security that crawls the internet to identify phishing infrastructure before attacks launch. Integration with Cloudflare’s network, which handles roughly 20% of global web traffic, provides unique threat intelligence from network-level visibility.
Preemptive phishing identification crawls attacker infrastructure before campaigns launch. Cloudflare network intelligence comes from processing roughly 20% of global web traffic. The platform ranked in the top three in “current offering” category as a Strong Performer in the 2025 Forrester Wave. API and MX-based deployment options are both available. Integration with Cloudflare Zero Trust enables end-to-end protection. Pricing stays competitive relative to standalone email security vendors.
Best for: Cloudflare Zero Trust customers wanting email security integrated with their existing network security platform
6. Check Point Harmony Email & Collaboration
Score: 85/100
Check Point Harmony Email protects Microsoft 365, Google Workspace, and collaboration platforms (Teams, Slack, SharePoint, OneDrive) from a single API-integrated solution. The platform leverages ThreatCloud AI, Check Point’s global threat intelligence network.
Multi-platform coverage spans Microsoft 365, Google Workspace, Teams, Slack, SharePoint, and OneDrive. ThreatCloud AI leverages global threat intelligence from Check Point’s install base. API-based deployment requires no MX record changes. Integrated DLP covers email and collaboration platforms. Unified management connects with Harmony Endpoint and Harmony SASE. Strong phishing simulation and training capabilities are included.
Best for: Check Point customers wanting email and collaboration security integrated with their existing Harmony security suite
7. Cisco Secure Email (+ IronPort)
Score: 83/100
Cisco Secure Email leverages Talos threat intelligence, one of the largest commercial threat research operations, and integrates with the broader Cisco Security Cloud. The Splunk acquisition adds SIEM correlation capabilities for email-related threat investigation.
Talos threat intelligence comes from one of the largest commercial threat research teams. Advanced Malware Protection uses sandboxing and retrospective alerting. Integration with Cisco XDR and Splunk enables email threat correlation. Graymail management and URL filtering are included. Cloud and on-premises deployment options are both available. The platform works well for organizations with existing Cisco infrastructure.
Best for: Cisco infrastructure customers wanting email security backed by Talos threat intelligence and integrated with Cisco XDR
8. Barracuda Email Security Gateway
Score: 81/100
Barracuda provides accessible email security for mid-market organizations with straightforward deployment and management. The platform covers inbound and outbound filtering, archiving, and email continuity with predictable per-user pricing.
Simple deployment and management target mid-market IT teams. Inbound and outbound email filtering uses content analysis. Email archiving and eDiscovery capabilities are included. Incident response includes post-delivery remediation. Office 365 and on-premises Exchange are both supported. Predictable per-user pricing avoids hidden costs.
Best for: Mid-market organizations wanting straightforward email security with archiving at predictable pricing
9. IRONSCALES
Score: 79/100
IRONSCALES combines AI-powered detection with crowdsourced threat intelligence from its customer community. The platform emphasizes rapid deployment and self-learning capabilities that improve detection over time based on analyst feedback and community reports.
Self-learning AI improves based on analyst feedback and remediation actions. Crowdsourced threat intelligence comes from the IRONSCALES customer community. Integrated phishing simulation and security awareness training are included. Automated post-delivery remediation is standard. Mailbox-level anomaly detection catches BEC and account compromise. Rapid deployment uses API-based integration.
Best for: Organizations wanting AI-powered email security that continuously learns from community intelligence and analyst feedback
10. Perception Point
Score: 77/100
Perception Point provides email and collaboration security with fast detection SLAs, scanning every email, file, and URL in under 30 seconds. The platform extends beyond email to protect Slack, Teams, Zendesk, Salesforce, and cloud storage platforms.
Sub-30-second scanning SLA covers every email, file, and URL. Multi-channel protection spans email, Slack, Teams, Zendesk, Salesforce, and cloud storage. HAP (Hardware-based Analysis Platform) provides evasion-resistant sandboxing. Managed incident response service comes included. Browser Security extension adds web-based threat protection. A growing channel partner ecosystem supports distribution.
Best for: Organizations needing fast detection SLAs and multi-channel protection across email and collaboration platforms
Where the Market Is Heading
Several trends are shaping email security in 2026.
API-native is replacing gateway. Abnormal AI’s success validates the API-first, gateway-optional model. MX record-based deployment is declining.
Multi-channel coverage is mandatory. Attackers exploit Slack, Teams, file-sharing, and voice alongside email. Single-channel email security is no longer sufficient.
Human Risk Management is emerging. Proofpoint’s HRM and awareness training integration reflects the shift from “block threats” to “reduce human risk” as a measurable metric.
Layered security is standard. 63% of security leaders now use two or more email security vendors, typically combining Microsoft’s built-in protection with a third-party AI layer.
BEC is overtaking malware. Business email compromise and social engineering attacks are more profitable and harder to detect than malware, driving AI investment in behavioral and language analysis.