This detection rule identifies when a user in the Microsoft 365 environment has been restricted from sending emails due to exceeding the predefined sending limits set by the Security Compliance Center. The detection relies on monitoring events generated by the Security Compliance Center related to email sending restrictions. When a user attempts to send an email and is flagged by the system for exceeding limits, this rule triggers an alert indicating the user's inability to send further communications. It is crucial to monitor such instances to prevent account misuse or to investigate potential malicious activity that led to the restriction. The rule is categorized as medium-level risk and aligns with necessary compliance checks to maintain the integrity of the email service. This can help organizations react promptly to possibly compromised accounts or unintentional abuses of email policies.