What is a disconnected mailbox in Exchange?
Exchange server is a popular messaging and email communication application in both small and large organizations, and user mailboxes in the server contain massive amounts of data. When a mailbox is disconnected from the Exchange server, it is no longer associated with an active directory user account. When an employee leaves an organization or a person no longer exists, the mailbox associated with them is disabled. The mailboxes also become disconnected when an Exchange administrator manually deletes or disables such mailboxes from the Exchange admin center (EAC) or by using PowerShell cmdlets. Deleted and disabled mailboxes are also referred to as disconnected mailboxes and often required in situations where data must be archived or retrieved for data compliance and legal reasons.
What happens when an Exchange mailbox is disabled?
When an Exchange mailbox is disabled, the user account is retained while the Exchange attributes are removed from Active Directory (AD), but when the mailbox is deleted, both the attributes and AD associations are removed. A deleted Exchange mailbox is marked as disabled and retained in the database until it is finally purged.