How to Check Mailbox Sizes in Office 365 with PowerShell
Overview Tracking mailbox sizes in Office 365 is critical for managing storage and preventing disruptions. Our tenant has a large number of mailboxes. We needed a way to check active users and their current storage usage accurately. Microsoft’s built-in tools lag by multiple days and don’t provide a real-time view of mailbox sizes. To solve this, I created a PowerShell script that: Pulls real-time mailbox size data using Microsoft’s CLI tools Targets a specific distribution list instead of scanning the entire tenant Exports results to a CSV file for tracking and analysis Ensures we work with up-to-date and accurate data This approach helps IT teams proactively manage storage and avoid mailbox overages. ...