When using the Exchange Management Shell to view mailbox properties using the get-mailbox task, the output of the task may contain the following information:
The value of "unlimited" above can be deceiving depending on the circumstance. In order to truly evaluate what the current storage quota status is, it is necessary to also look at the UseDatabaseQuotaDefaults parameter. A value of TRUE on UseDatabaseQuotaDefaults means that the per-mailbox settings are ignored and the mailbox database defaults are used.
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