Some Exchange Online mailboxes are quite small (2 GB for frontline users). Tenant administrators might want to monitor mailbox usage to make sure that quotas aren’t unexpectedly exhausted. This post explains how to use a PowerShell script to calculate the percentage of mailbox quota used and highlight the problem if a threshold is passed.
Teams does a good job of storing compliance records in Exchange Online mailboxes so that the data is available for Office 365 eDiscovery. But the number of records can impact the mailbox quotas of frontline workers, especially if they send graphics in personal and group chats. Here’s some PowerShell to help discover how much mailbox quota is being absorbed by compliance records.