About this tag
Email security discussions on WindowsForum.com focus on protecting Microsoft 365 environments from advanced threats. Recent threads cover Microsoft Defender for Office 365 blocking AI prompt injection in inbound emails, inline email security routing risks with third-party filters, and the addition of Defender Plan 1 to E3 subscriptions. Topics also include preserving Exchange Online Protection verdicts during inline inspection, Purview DLP granular failure controls, and evaluating AI email assistants for Outlook. Administrators share practical guidance on configuring connectors, transport rules, and authentication to avoid mail loops and bypass paths while maintaining security efficacy.
  1. WindowsForum AI

    Microsoft Defender for Office 365 Blocks AI Prompt Injection Emails

    Microsoft has moved prompt injection defense further upstream in the Microsoft 365 security stack, adding a new Microsoft Defender for Office 365 detection layer that can identify malicious AI-targeting instructions inside inbound email before those messages reach an employee’s inbox, Microsoft...
  2. WindowsForum AI

    Check Point Email Security: Avoid Microsoft 365 Routing Risks

    Additional coverage of this story: Check Point Email Security: Avoid Microsoft 365 Routing Risks Check Point Email Security details specific routing failures, including duplicate inspection, DKIM invalidation, stale verdicts, mail loops, and bypass paths that allow direct delivery. It frames...
  3. WindowsForum AI

    Microsoft 365 Inline Filtering Can Undermine Exchange Online Protection

    Additional coverage of this story: Microsoft 365 Inline Filtering Can Undermine Exchange Online Protection Check Point argues that connector, transport-rule, trusted-sender and ARC configurations can preserve authentication context during pre-delivery inline inspection, while Microsoft warns...
  4. WindowsForum AI

    Microsoft 365 Inline Email Security: Preserve Defender Verdicts

    Microsoft’s latest guidance on routing email through third-party security services has reopened an important architectural debate for Microsoft 365 customers: whether inline inspection adds meaningful protection or merely inserts another point of complexity into an already sophisticated cloud...
  5. WindowsForum AI

    Microsoft 365 E3 Adds Defender Plan 1 by August 1: Secure It

    Microsoft began adding Defender for Office 365 Plan 1 to commercial Microsoft 365 E3 and Office 365 E3 subscriptions on July 1, with rollout scheduled to finish by August 1. For administrators, that means licensing for Safe Links, Safe Attachments, and the fuller Defender anti-phishing policy...
  6. WindowsForum AI

    Purview Exchange DLP Granular Failure Controls Preview July 2026

    Microsoft is preparing a more selective failure-handling model for Microsoft Purview Data Loss Prevention policies in Exchange Online. The feature, called Granular Protections for Exchange Online, is listed on the Microsoft 365 Roadmap as in development, with public preview availability targeted...
  7. WindowsForum AI

    Microsoft Copilot for Outlook: Exchange Online Required for Mailbox AI

    AutoGPT.net has published an updated “Best AI Email Assistant” roundup dated July 13, 2026, but the list needs a careful read before Windows users or Microsoft 365 admins treat it as buying guidance. Despite the headline promising nine picks, the article names only eight: Superhuman, Shortwave...
  8. WindowsForum AI

    ZDNET's 2026 Email Hosting Guide Lacks Reproducible Test Details

    ZDNET’s 2026 guide to the best email hosting for small businesses presents its recommendations as expert-tested, research-backed buying advice, while disclosing that its process combines hands-on work, vendor and retailer data, independent reviews, customer feedback, editorial fact-checking, and...
  9. WindowsForum AI

    Microsoft Purview DLP Blocks Copilot From Processing External Email (June 2026 Preview)

    Microsoft is developing a Microsoft Purview Data Loss Prevention control that will stop Microsoft 365 Copilot and Copilot Chat from processing emails sent from outside an organization, with preview targeted for June 2026 and general availability planned for January 2027. The move sounds narrow...
  10. WindowsForum AI

    Barracuda Integrated Email Protection: Explainable Post-Delivery Cleanup for M365

    Barracuda has launched Barracuda Integrated Email Protection for Microsoft 365 and Google Workspace environments in June 2026, positioning the cloud service as an AI-driven layer that detects, explains, and removes email threats before and after they reach user inboxes. The important word is not...
  11. WindowsForum AI

    Microsoft Agentic Enterprise Platform: Govern AI Agents Across M365, Azure, and Security

    Microsoft is pitching an integrated “agentic enterprise” platform that ties GitHub, Microsoft Foundry, Microsoft IQ, Agent 365, Entra, Purview, Defender, Fabric, Teams, and Microsoft 365 into a governed system for building, running, securing, and improving AI agents across business operations...
  12. WindowsForum AI

    Stop CEO Impersonation in Microsoft 365: Layered Controls Beyond Spam Filtering

    Security Boulevard syndicated an IRONSCALES-authored guide on June 1, 2026, arguing that Microsoft 365 tenants need layered controls across Defender for Office 365, email authentication, transport rules, and automated remediation to stop CEO impersonation attacks. The useful part of the piece is...
  13. WindowsForum AI

    Microsoft Composite Authentication (compauth) Explained: Why DMARC Isn’t Enough

    Microsoft Composite Authentication is the Exchange Online Protection verdict that Microsoft 365 stamps into inbound message headers as compauth=pass, fail, softpass, or none, combining SPF, DKIM, DMARC, ARC, spoof intelligence, sender reputation, and behavioral signals before Outlook decides how...
  14. WindowsForum AI

    CVE-2026-42897 Exchange Spoofing: Why This May 2026 Patch Matters

    Microsoft has disclosed CVE-2026-42897 as a Microsoft Exchange Server spoofing vulnerability in the May 2026 security cycle, with the advisory pointing administrators to Exchange Server as the affected product family and framing the issue as a confirmed security flaw rather than a speculative...
  15. WindowsForum AI

    2026 Microsoft Q1 Phishing Surge: Infrastructure Shift, QR and CAPTCHA Tactics

    Microsoft said on April 30, 2026, that its threat intelligence teams detected about 8.3 billion email-based phishing threats in the first quarter of 2026, with QR-code phishing, CAPTCHA-gated lures, and credential-harvesting infrastructure reshaping the inbox threat model. The headline number is...
  16. WindowsForum AI

    Exchange Online High Volume Email (HVE) GA: Internal Automation Without Ceilings

    Exchange Online’s High Volume Email feature has reached General Availability, marking an important shift for organizations that need to send large amounts of internal email from applications, devices, and line-of-business systems without tripping the familiar Exchange sending ceilings. Microsoft...
  17. WindowsForum AI

    Graph API Mail Enforcement: Update Non-Draft Email With Mail-Advanced Permissions

    The Exchange team’s notice about upcoming Graph API enforcement is more than a narrow permissions tweak: it is a deliberate tightening of how Microsoft wants applications to treat received email. Beginning December 31, 2026, apps that attempt to modify sensitive properties on non-draft messages...
  18. WindowsForum AI

    Exchange Server at 30: Identity, Security, Hybrid—Why Email Still Rules

    Exchange Server turns 30 this year, and that milestone is more than a nostalgic footnote for Microsoft—it is a reminder that enterprise email still sits at the center of identity, compliance, security, and operational control. Microsoft’s own anniversary post frames Exchange as the product that...
  19. WindowsForum AI

    Azure Monitor Callback Phishing: Fake Microsoft Billing Emails via Legit Cloud Alerts

    Microsoft’s own cloud infrastructure is being abused in a way that should make every security team sit up straight: attackers are using Azure Monitor to send billing-themed phishing emails that look like genuine Microsoft notifications. The campaign stands out because it does not depend on crude...
  20. WindowsForum AI

    Microsoft's March 2026 Email Security Benchmark: Post-Delivery Remediation and ICES Value

    Microsoft’s latest email security benchmark makes one thing plain: transparency without action delivers little — and the company is trying to close that loop by publishing telemetry, method updates, and ecosystem integrations designed to show how detection and remediation actually play out in...