M365EXO-039: Spam routed to junk or quarantine (MS.EXO.14.2)

Platform
Entra ID / M365
Category
Advanced Threat Protection
Severity
Medium
Zero Trust pillar
Applications & Workloads (weight 1)
Golden fixtures
3
Branch coverage
Observed: fixtures prove the verdicts they exercise
Provenance
baseline

What it checks

SCuBA MS.EXO.14.2 requires that spam and high confidence spam be moved to either the junk email folder or quarantine. Delivering spam to the inbox defeats the purpose of filtering and increases exposure to malicious content. The anti-spam policy actions must route detected spam away from the inbox while preserving user review of false positives.

Recommended value

SpamAction and HighConfidenceSpamAction set to MoveToJmf (junk) or Quarantine; never set to deliver to inbox

Remediation

Configure the anti-spam policy so the spam and high confidence spam actions move messages to the junk email folder or quarantine rather than delivering them to the inbox. Verify neither action is set to add a header and deliver. Confirm the policy applies to all recipients so spam routing is consistent.

Fixture-proven verdicts

Every verdict below is proven by a golden fixture in the module's gating test suite. This table derives from the last green run; it cannot be edited by hand.

Verdict scenarios for M365EXO-039
ScenarioExpected verdict
cleanPASS
known-badFAIL
throttledNot Assessed

Framework mappings

NIST SP 800-53
SI-8
MITRE ATT&CK
T1566