Get-Mailbox (ExchangePowerShell)

When you use the Get-Mailbox cmdlet in on-premises Exchange environments to view the quota settings for a mailbox, you first need to check the value of the UseDatabaseQuotaDefaults property. The value True means per-mailbox quota settings are ignored, and you need to use the Get-MailboxDatabase cmdlet to see the actual values. If the UseDatabaseQuotaDefaults property is False, the per-mailbox quota settings are used, so what you see with the Get-Mailbox cmdlet are the actual quota values for the mailbox. You need to be assigned permissions before you can run this cmdlet. Although this article lists all parameters for the cmdlet, you might not have access to some parameters if they aren't included in the permissions assigned to you. To find the permissions required to run any cmdlet or parameter in your organization, see Find the permissions required to run any Exchange cmdlet.