4.1

MetaDefender for Microsoft 365 is an advanced solution that bolsters Microsoft 365’s native defenses with industry-leading threat prevention for email and files shared through Microsoft Teams. It is purpose-built to detect and neutralize malware, zero-day exploits, and embedded file-based threats, helping protect users across email and collaboration workflows.

This solution is powered by OPSWAT’s Metascan™ Multiscanning, adding more AV (antivirus) engines, MetaDefender Aether Sandbox for advanced dynamic threat analysis, and Deep CDR™ (Content Disarm & Reconstruction) for proactive content sanitization. By combining signature-based detection, behavioral sandboxing, and content sanitization, protection extends beyond traditional defenses to identify and neutralize both known and zero-day threats. With multiple layers of proactive protection and advanced technologies designed to combat evolving attack techniques, the solution deploys rapidly and integrates seamlessly with Microsoft 365, minimizing disruption to mail flow and Teams collaboration.

Enhancements

• Added scheduled reminder notifications for quarantined emails and blocked Teams messages, configurable per verdict

• Added before/after configuration change details to audit log entries for policies and other configuration objects

Onboarding

• Fixed onboarding forcing the Authorize step when admin consent already exists in the tenant

Bugs

• Fixed successful delivery retries marking emails as Released instead of Delivered

• Fixed Teams policies ignoring the "Store sanitized original" setting

• Fixed "Not Sanitized" result shown for successfully sanitized files

• Fixed clean files being marked as threats on the Actions page

• Fixed policy creation so an Inbound/Outbound direction must always be selected

• Fixed the policy editor hiding the Additional Filters tab when the Teams channel adds the Internal direction

• Fixed policy configuration showing the template name for allowed actions

• Fixed OTP event details for Teams messages so the fields match the message type

• Fixed "Add to Allowlist" staying enabled in File Details for files already on the allowlist

• Fixed incorrect filter count when navigating from Action Items to Events

• Fixed Recent Activity showing an overly long list of email addresses