3.18

MetaDefender Cloud Email Security™ is an advanced solution that bolsters Microsoft 365’s native email defenses with industry-leading threat prevention. It is purpose-built to detect and neutralize malware, zero-day exploits, and embedded file-based threats before they reach the inbox.

This solution is powered by OPSWAT’s Metascan™ Multiscanning, adding more AV (antivirus) engines, and Deep CDR™ (Content Disarm & Reconstruction) against file-based threats. With multi-layered, proactive protection, email security goes beyond signature-based detection with advanced technologies against evolving threats. Designed for seamless integration, the solution deploys rapidly without disrupting mail flow.

Improvements & Fixes

Allowlist

• Introduced scope-based Email Sender Allowlist, allowing configurable security bypass levels.

Events

• Added flags for:

  • Signed / Encrypted emails (sanitization skipped)

  • Emails delivered after correct password provided.

Integration wizard

• Added Summary step during onboarding

• Implemented consent polling and auto-resume onboarding (Microsoft Entra).

Mailflow & Processing

• Improved ARC signing/sealing support.

• Fixed processing latency calculation

• Fixed suspicious files inside archives returning incorrect overall verdict

• Fixed txt/html attachments not appearing in Attachments tab

• Fixed empty plain text bodies causing “Failure to Analyze” verdict

• Fixed failed-to-scan verdict incorrectly marked as “Skipped” instead of “Failure to Analyze”

• Fixed allowlisted emails with Deep CDR disabled not detecting encrypted content