For a Microsoft 365 Business Basic user with a 50 GB primary mailbox and a Microsoft Purview retention policy applied, does content moved to Recoverable Items count against the same 50 GB mailbox limit? For example, when a message is deleted and retained, does it use the primary mailbox quota, or is there a separate storage limit for retained and deleted items?
3 Answers
To check the separate deleted-item usage for a mailbox, an administrator can inspect the mailbox statistics and look at TotalDeletedItemSize. That helps identify whether Recoverable Items is approaching its own limit, regardless of how much space remains in the primary mailbox.
They use separate quotas. The Recoverable Items folder has its own storage limit rather than consuming space from the primary mailbox's 50 GB quota. The exact limit depends on the mailbox state and whether it's subject to a hold; commonly, it can be around 30 GB for an ordinary mailbox and higher for mailboxes on hold. This means a mailbox can have plenty of free primary storage while Recoverable Items is already full.
Retention and deletion behavior can be confusing here. Items retained by a Purview policy may remain in hidden Recoverable Items locations and are governed by the Recoverable Items quota, not the normal mailbox quota. After the retention period ends, the item can be permanently removed, depending on the policy. This is different from a litigation or other hold, which can preserve content for as long as the hold remains active.
A full Recoverable Items quota can also cause Outlook to report that the mailbox is full or behave strangely, even when the primary mailbox itself is well below its limit.