The rule 'PowerShell Mailbox Collection Script' is designed to identify potentially malicious PowerShell scripts which could be utilized to access and collect data from email mailboxes. This is particularly concerning as sensitive information contained within email accounts can be targeted by adversaries. The detection is centered around configurations in PowerShell that suggest abnormal mailbox interactions, such as references to Microsoft Office and Exchange Web Services APIs for local or remote email retrieval. Analysts are advised to analyze triggered script contents thoroughly for suspicious activities, DLL imports, and execution chains. Key actions following detection should involve incident response protocols, user investigations, and potential system isolation if needed.