Microsoft publishes quarterly email security benchmarking data comparing Microsoft Defender against secure email gateway (SEG) and integrated cloud email security (ICES) vendors using real-world threat telemetry.

A year ago, we set out to change how email security effectiveness is measured. With our first benchmarking report in July 2025, we committed to publishing real-world performance data, not synthetic tests, so security teams could make decisions grounded in evidence. With each quarterly update, we refined our methodology, expanded our analysis, and listened to customer and partner feedback.

Alongside it, we established the Microsoft Defender ICES vendor ecosystem, designed to enable seamless integration with trusted third-party vendors and streamline security operations center (SOC) workflows for organizations who have chosen a multi-vendor email security strategy.

Key insights from a year of email benchmarking

With four consecutive quarters, several findings have proven to be durable insights, highlighting the sustained realities of how layered email security performs in production:

1. Defender consistently leads in pre-delivery detection. Across every benchmarking period since July 2025, Defender has missed fewer high-severity cyberthreats than every SEG vendor evaluated, while the next closest SEG vendor had 2.5 times more misses.

2. ICES vendors add the most value in promotional and bulk email filtering. Promotional filtering uplift has been the clearest area of ICES value with an average uplift of 15% over the four quarters of evaluation. Meanwhile ICES vendor uplift for malicious catch and spam has consistently remained relatively nominal, averaging at 0.29% and 0.68%, respectively. In addition, over the last three quarters we’ve seen a consistent downward trend in these numbers, as we have continued to drive innovation in post-delivery mail detection.

3. Defender’s share of post-delivery remediation has grown significantly. In our second report, we introduced insights on the contribution of Defender to post-delivery malicious catch. Initially, Defender contributed 45% of post-delivery malicious catch, which has since risen to an average of 96%. This trajectory underscores that Microsoft’s post-delivery catch is an increasingly critical backstop, operating even when ICES solutions are in place, and that Defender is delivering the majority of post-delivery remediation.

SEG vendor benchmarking results

For SEG vendors, a threat is classified as “missed” if it was not detected prior to delivery. Using this definition, Microsoft Defender once again missed fewer high-severity email threats than all other solutions evaluated, consistent with every prior benchmarking period.

This quarter, Defender missed 59% fewer high-severity threats than the next-closest SEG vendor, a gap that has remained consistent across all four benchmarking periods.

ICES vendor benchmarking results

ICES solutions operating on top of Microsoft Defender continue to provide benefit, particularly in reducing promotional and bulk email, with an average improvement of 16.85% over the last quarter. This helps minimize inbox clutter and improves user productivity in environments where promotional noise is a concern. For malicious messages and spam, the average improvement across vendors was 0.13% for malicious and 0.28% for spam catch, compared to 0.24% and 0.29% in the prior report.

Focusing only on malicious messages that reached the inbox, the latest quarter shows Microsoft Defender’s post-delivery catch continues to improve, catching the majority of post‑delivery remediation. It removes an average of 96.03%, up from 70.8% in the previous quarter, highlighting the effectiveness of our continuous investments in this area. Post‑delivery remediation remains a critical backstop when cyberthreats evade initial filtering.

Innovation shaped by benchmarking insights

Benchmarking doesn’t just help customers make better decisions. It shapes what we build. Over the past year we’ve used the insights from our benchmarking reports, as well as insights from the growing ICES vendor ecosystem, to directly shape our innovation and product outcomes. Below are some of the most recent highlights, that we directly attribute to the continued improvements in Microsoft Defender performance.

Native promotion and bulk mail filtering in Outlook: A dedicated Promotions folder, natively provisioned in Outlook, now keeps legitimate bulk mail out of the primary inbox. Promotional content is separated from priority emails without being sent to Junk, which means users can still access and browse newsletters and updates at their own pace. The folder appears at the top level of the mailbox for easy discovery and is visible across all Outlook experiences. Once generally available it will be on by default, improving the native promotional filtering. Learn more.

System-level AI advancements: Among other AI enhancements, in November 2025 we introduced an agentic grading system that reduces the reliance on manual review in the submission and analysis pipeline. It helps deliver lower wait times, faster responses, and higher-quality results when emails are submitted to Microsoft for review. That means security teams can investigate reported messages more efficiently, respond more promptly, and act with greater confidence against phishing threats. Learn more.

Accelerating investigation with AI: The growing role of post-delivery remediation in our benchmarking data highlights a related challenge: when threats reach users and get reported, SOC teams need to triage those submissions quickly and accurately. The Microsoft Security Copilot Alert Triage Agent uses language model-powered reasoning to classify user-reported phishing emails, resolve false positives, and escalate confirmed threats for analyst review. Results show analysts identify 6.5 times more malicious alerts, improve verdict accuracy by 77%, and spend 53% more time investigating real cyberthreats. Security Copilot’s Email Summary further speeds investigations by turning email detection data into clear, actionable insights in the Email entity page. Learn more.

A year into this effort, our commitment to transparent benchmarking remains unchanged. We’ll continue using these insights to shape product innovation, share real-world performance data with customers, and invest in a strong ecosystem that meets organizations where they are—supporting the layered email security strategies that work best for their environments.

Learn more

Learn more about Microsoft Defender.

To learn more about Microsoft Security solutions, visit our website. Bookmark the Security blog to keep up with our expert coverage on security matters. Also, follow us on LinkedIn (Microsoft Security) and X (@MSFTSecurity) for the latest news and updates on cybersecurity.

The post Microsoft Defender email security benchmarking: Key insights from one year of data appeared first on Microsoft Security Blog.

Microsoft publishes quarterly email security benchmarking data comparing Microsoft Defender against secure email gateway (SEG) and integrated cloud email security (ICES) vendors using real-world threat telemetry.

A year ago, we set out to change how email security effectiveness is measured. With our first benchmarking report in July 2025, we committed to publishing real-world performance data, not synthetic tests, so security teams could make decisions grounded in evidence. With each quarterly update, we refined our methodology, expanded our analysis, and listened to customer and partner feedback.

Alongside it, we established the Microsoft Defender ICES vendor ecosystem, designed to enable seamless integration with trusted third-party vendors and streamline security operations center (SOC) workflows for organizations who have chosen a multi-vendor email security strategy.

Key insights from a year of email benchmarking

With four consecutive quarters, several findings have proven to be durable insights, highlighting the sustained realities of how layered email security performs in production:

1. Defender consistently leads in pre-delivery detection. Across every benchmarking period since July 2025, Defender has missed fewer high-severity cyberthreats than every SEG vendor evaluated, while the next closest SEG vendor had 2.5 times more misses.

2. ICES vendors add the most value in promotional and bulk email filtering. Promotional filtering uplift has been the clearest area of ICES value with an average uplift of 15% over the four quarters of evaluation. Meanwhile ICES vendor uplift for malicious catch and spam has consistently remained relatively nominal, averaging at 0.29% and 0.68%, respectively. In addition, over the last three quarters we’ve seen a consistent downward trend in these numbers, as we have continued to drive innovation in post-delivery mail detection.

3. Defender’s share of post-delivery remediation has grown significantly. In our second report, we introduced insights on the contribution of Defender to post-delivery malicious catch. Initially, Defender contributed 45% of post-delivery malicious catch, which has since risen to an average of 96%. This trajectory underscores that Microsoft’s post-delivery catch is an increasingly critical backstop, operating even when ICES solutions are in place, and that Defender is delivering the majority of post-delivery remediation.

SEG vendor benchmarking results

For SEG vendors, a threat is classified as “missed” if it was not detected prior to delivery. Using this definition, Microsoft Defender once again missed fewer high-severity email threats than all other solutions evaluated, consistent with every prior benchmarking period.

This quarter, Defender missed 59% fewer high-severity threats than the next-closest SEG vendor, a gap that has remained consistent across all four benchmarking periods.

ICES vendor benchmarking results

ICES solutions operating on top of Microsoft Defender continue to provide benefit, particularly in reducing promotional and bulk email, with an average improvement of 16.85% over the last quarter. This helps minimize inbox clutter and improves user productivity in environments where promotional noise is a concern. For malicious messages and spam, the average improvement across vendors was 0.13% for malicious and 0.28% for spam catch, compared to 0.24% and 0.29% in the prior report.

Focusing only on malicious messages that reached the inbox, the latest quarter shows Microsoft Defender’s post-delivery catch continues to improve, catching the majority of post‑delivery remediation. It removes an average of 96.03%, up from 70.8% in the previous quarter, highlighting the effectiveness of our continuous investments in this area. Post‑delivery remediation remains a critical backstop when cyberthreats evade initial filtering.

Innovation shaped by benchmarking insights

Benchmarking doesn’t just help customers make better decisions. It shapes what we build. Over the past year we’ve used the insights from our benchmarking reports, as well as insights from the growing ICES vendor ecosystem, to directly shape our innovation and product outcomes. Below are some of the most recent highlights, that we directly attribute to the continued improvements in Microsoft Defender performance.

Native promotion and bulk mail filtering in Outlook: A dedicated Promotions folder, natively provisioned in Outlook, now keeps legitimate bulk mail out of the primary inbox. Promotional content is separated from priority emails without being sent to Junk, which means users can still access and browse newsletters and updates at their own pace. The folder appears at the top level of the mailbox for easy discovery and is visible across all Outlook experiences. Once generally available it will be on by default, improving the native promotional filtering. Learn more.

System-level AI advancements: Among other AI enhancements, in November 2025 we introduced an agentic grading system that reduces the reliance on manual review in the submission and analysis pipeline. It helps deliver lower wait times, faster responses, and higher-quality results when emails are submitted to Microsoft for review. That means security teams can investigate reported messages more efficiently, respond more promptly, and act with greater confidence against phishing threats. Learn more.

Accelerating investigation with AI: The growing role of post-delivery remediation in our benchmarking data highlights a related challenge: when threats reach users and get reported, SOC teams need to triage those submissions quickly and accurately. The Microsoft Security Copilot Alert Triage Agent uses language model-powered reasoning to classify user-reported phishing emails, resolve false positives, and escalate confirmed threats for analyst review. Results show analysts identify 6.5 times more malicious alerts, improve verdict accuracy by 77%, and spend 53% more time investigating real cyberthreats. Security Copilot’s Email Summary further speeds investigations by turning email detection data into clear, actionable insights in the Email entity page. Learn more.

A year into this effort, our commitment to transparent benchmarking remains unchanged. We’ll continue using these insights to shape product innovation, share real-world performance data with customers, and invest in a strong ecosystem that meets organizations where they are—supporting the layered email security strategies that work best for their environments.

Learn more

Learn more about Microsoft Defender.

To learn more about Microsoft Security solutions, visit our website. Bookmark the Security blog to keep up with our expert coverage on security matters. Also, follow us on LinkedIn (Microsoft Security) and X (@MSFTSecurity) for the latest news and updates on cybersecurity.

The post Microsoft Defender email security benchmarking: Key insights from one year of data appeared first on Microsoft Security Blog.

In our last benchmarking post, Clarity in complexity: New insights for transparent email security,¹ we shared why transparency matters more than ever in email security and how clear, consistent benchmarking helps security teams cut through noise and make confident decisions.

Today, we’re continuing that conversation. With the latest Microsoft benchmarking data, we’re sharing what real-world telemetry reveals about how effectively modern email threats are detected, mitigated, and stopped by Microsoft Defender, secure email gateway (SEG) providers, and integrated cloud email security (ICES) solutions.

This is part of our ongoing commitment to openness: regularly publishing performance data so customers can see how protections perform at scale.

What’s new in the latest benchmarking data

The newest benchmarking results reflect updated telemetry across recent months and reinforce several consistent trends:

• Microsoft Defender removes an average of 70.8% of malicious email post-delivery, helping reduce dwell time even when cyberthreats bypass initial filtering.
• Layered protection matters. When Defender operates alongside ICES partners, organizations benefit from incremental detection gains across promotional, spam, and malicious messages.
• Overlapping detections remain, meaning ICES solutions can flag the same messages and the incremental value-add can vary by scenario and email type.

This kind of data-driven visibility is critical for security teams who want to understand not just whether cyberthreats are blocked, but how and where defenses are adding value across the email attack lifecycle.

Benchmarking results for ICES vendors

Microsoft’s quarterly analysis shows that layering ICES solutions with Microsoft Defender continue to provide a benefit in reducing marketing and bulk email, improving their filtering by an average of 13.7%. This reduces inbox clutter and boosts user productivity in environments with high volumes of promotional email. For filtering of spam and malicious messages, the incremental gains remain modest, and the latest quarter shows a smaller uplift than the prior period—averaging 0.29% and 0.24% respectively, compared to 1.65% and 0.5% in the prior report.

Focusing only on malicious messages that reached the inbox, the latest quarter shows Microsoft Defender’s zero hour auto purge performing the majority of post‑delivery remediation—removing an average of 70.8% of these threats. ICES vendors provided additional post‑delivery filtering, contributing an average of 29.2%. Together, this highlights two points: post‑delivery remediation is a critical backstop when cyberthreats evade initial filtering, and in these results Microsoft Defender delivered most of the post‑delivery catch, while ICES vendors add incremental coverage in this scenario.

Benchmarking results for SEG vendors

For the SEG vendor benchmarking metrics, a cyberthreat was classified as “missed” if it was not detected prior to delivery. Using this definition, Microsoft Defender missed fewer high-severity cyberthreats than other solutions evaluated in the study, consistent with patterns observed in our prior benchmarking report.

Reinforcing our commitment to the ICES vendor ecosystem

Transparency doesn’t stop at Microsoft’s own detections. It also extends to how we work with partners.

When we introduced the Microsoft Defender for Office 365 ICES vendor ecosystem, our goal was clear: enable customers to integrate trusted, non-Microsoft email security solutions into a unified Defender experience, without fragmenting workflows or visibility.

That commitment continues today.

• The ICES vendor ecosystem now includes four partners—Darktrace, KnowBe4, Cisco, and VIPRE Security Group—all integrated directly into Microsoft Defender across experiences such as Quarantine, Explorer, email entity pages, advanced hunting, and reporting.
• Customers retain a single operational plane in the Defender portal, even when layering multiple email security technologies.
• Integrations are deliberate and additive, designed to enhance protection and clarity without increasing operational complexity.
• The ecosystem supports defense-in-depth strategies while preserving a single, coherent security experience.

The recent additions reinforce our belief that email security is strongest when it combines native platform intelligence with specialized partner capabilities, surfaced through a single pane of glass.

We continue to actively evaluate additional partnerships based on customer demand, detection quality, and the ability to deliver meaningful, differentiated signals.

Why this matters for security teams

Email remains one of the most targeted and exploited attack vectors, and modern campaigns rarely rely on a single technique or control gap.

By pairing transparent benchmarking with integrated, multi-vendor protection, security teams gain:

• Clear insight into detection coverage across native and partner solutions.
• Reduced investigation friction with unified views and workflows.
• Confidence in layered defenses, backed by regularly published data.

This isn’t about claiming perfection. It’s about showing the work, sharing the numbers, and giving customers the information they need to make informed security decisions.

Looking ahead

We’ll continue to publish updated benchmarking insights on a regular basis, alongside ongoing investments in Microsoft Defender and the ICES vendor ecosystem.

To explore the latest benchmarking data and learn more about how Defender and ICES partners work together, access the benchmarking site.

To learn more about Microsoft Security solutions, visit our website. Bookmark the Security blog to keep up with our expert coverage on security matters. Also, follow us on LinkedIn (Microsoft Security) and X (@MSFTSecurity) for the latest news and updates on cybersecurity.

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¹Clarity in complexity: New insights for transparent email security, Microsoft. December 10, 2025.

The post From transparency to action: What the latest Microsoft email security benchmark reveals appeared first on Microsoft Security Blog.

In our last benchmarking post, Clarity in complexity: New insights for transparent email security,¹ we shared why transparency matters more than ever in email security and how clear, consistent benchmarking helps security teams cut through noise and make confident decisions.

Today, we’re continuing that conversation. With the latest Microsoft benchmarking data, we’re sharing what real-world telemetry reveals about how effectively modern email threats are detected, mitigated, and stopped by Microsoft Defender, secure email gateway (SEG) providers, and integrated cloud email security (ICES) solutions.

This is part of our ongoing commitment to openness: regularly publishing performance data so customers can see how protections perform at scale.

What’s new in the latest benchmarking data

The newest benchmarking results reflect updated telemetry across recent months and reinforce several consistent trends:

• Microsoft Defender removes an average of 70.8% of malicious email post-delivery, helping reduce dwell time even when cyberthreats bypass initial filtering.
• Layered protection matters. When Defender operates alongside ICES partners, organizations benefit from incremental detection gains across promotional, spam, and malicious messages.
• Overlapping detections remain, meaning ICES solutions can flag the same messages and the incremental value-add can vary by scenario and email type.

This kind of data-driven visibility is critical for security teams who want to understand not just whether cyberthreats are blocked, but how and where defenses are adding value across the email attack lifecycle.

Benchmarking results for ICES vendors

Microsoft’s quarterly analysis shows that layering ICES solutions with Microsoft Defender continue to provide a benefit in reducing marketing and bulk email, improving their filtering by an average of 13.7%. This reduces inbox clutter and boosts user productivity in environments with high volumes of promotional email. For filtering of spam and malicious messages, the incremental gains remain modest, and the latest quarter shows a smaller uplift than the prior period—averaging 0.29% and 0.24% respectively, compared to 1.65% and 0.5% in the prior report.

Focusing only on malicious messages that reached the inbox, the latest quarter shows Microsoft Defender’s zero hour auto purge performing the majority of post‑delivery remediation—removing an average of 70.8% of these threats. ICES vendors provided additional post‑delivery filtering, contributing an average of 29.2%. Together, this highlights two points: post‑delivery remediation is a critical backstop when cyberthreats evade initial filtering, and in these results Microsoft Defender delivered most of the post‑delivery catch, while ICES vendors add incremental coverage in this scenario.

Benchmarking results for SEG vendors

For the SEG vendor benchmarking metrics, a cyberthreat was classified as “missed” if it was not detected prior to delivery. Using this definition, Microsoft Defender missed fewer high-severity cyberthreats than other solutions evaluated in the study, consistent with patterns observed in our prior benchmarking report.

Reinforcing our commitment to the ICES vendor ecosystem

Transparency doesn’t stop at Microsoft’s own detections. It also extends to how we work with partners.

When we introduced the Microsoft Defender for Office 365 ICES vendor ecosystem, our goal was clear: enable customers to integrate trusted, non-Microsoft email security solutions into a unified Defender experience, without fragmenting workflows or visibility.

That commitment continues today.

• The ICES vendor ecosystem now includes four partners—Darktrace, KnowBe4, Cisco, and VIPRE Security Group—all integrated directly into Microsoft Defender across experiences such as Quarantine, Explorer, email entity pages, advanced hunting, and reporting.
• Customers retain a single operational plane in the Defender portal, even when layering multiple email security technologies.
• Integrations are deliberate and additive, designed to enhance protection and clarity without increasing operational complexity.
• The ecosystem supports defense-in-depth strategies while preserving a single, coherent security experience.

The recent additions reinforce our belief that email security is strongest when it combines native platform intelligence with specialized partner capabilities, surfaced through a single pane of glass.

We continue to actively evaluate additional partnerships based on customer demand, detection quality, and the ability to deliver meaningful, differentiated signals.

Why this matters for security teams

Email remains one of the most targeted and exploited attack vectors, and modern campaigns rarely rely on a single technique or control gap.

By pairing transparent benchmarking with integrated, multi-vendor protection, security teams gain:

• Clear insight into detection coverage across native and partner solutions.
• Reduced investigation friction with unified views and workflows.
• Confidence in layered defenses, backed by regularly published data.

This isn’t about claiming perfection. It’s about showing the work, sharing the numbers, and giving customers the information they need to make informed security decisions.

Looking ahead

We’ll continue to publish updated benchmarking insights on a regular basis, alongside ongoing investments in Microsoft Defender and the ICES vendor ecosystem.

To explore the latest benchmarking data and learn more about how Defender and ICES partners work together, access the benchmarking site.

To learn more about Microsoft Security solutions, visit our website. Bookmark the Security blog to keep up with our expert coverage on security matters. Also, follow us on LinkedIn (Microsoft Security) and X (@MSFTSecurity) for the latest news and updates on cybersecurity.

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¹Clarity in complexity: New insights for transparent email security, Microsoft. December 10, 2025.

The post From transparency to action: What the latest Microsoft email security benchmark reveals appeared first on Microsoft Security Blog.