Suspicious Microsoft 365 - User Restricted from Sending Email (via threat_management)

title: Suspicious Microsoft 365 - User Restricted from Sending Email (via threat_management)
id: 0cfe19b8-ede3-5325-a1fa-f814d453768b
status: stable
description: This rule detects when a Security Compliance Center reported a user who exceeded sending limits of the service policies and because of this has been restricted from sending email.
references:
    - https://attack.mitre.org/techniques/T1199/
    - https://learn.microsoft.com/en-us/defender-cloud-apps/anomaly-detection-policy
    - https://learn.microsoft.com/en-us/defender-cloud-apps/policy-template-reference
author: Huntrule Team
date: 2026-03-15
tags:
    - attack.initial-access
    - attack.t1199
logsource:
    service: threat_management
    product: m365
detection:
    selection:
        eventSource: SecurityComplianceCenter
        eventName: 'User restricted from sending email'
        status: success
    condition: selection
falsepositives:
    - Unknown
level: medium