Improving email security outcomes with real-world Microsoft Defender insights
Microsoft's quarterly benchmark claims Defender missed 55.4% fewer high-severity email threats than the next-closest secure email gateway.
Microsoft published its fifth consecutive quarterly email security benchmark covering May through July 2026, reporting Defender missed 221 high-severity threats per 1,000 protected users, 55.4% fewer than the next-closest SEG vendor, and caught 92% of post-delivery malicious messages. Microsoft notes missed threats are rising across vendors as AI helps attackers craft more convincing impersonation attempts. The report also highlights product updates, including a redesigned AI model stack that reduced false negatives by roughly two-thirds and new prompt injection protection for Copilot and other AI systems that process email.