Understanding Disconnected Mailboxes: Archive and Disabled

When it comes to managing mailboxes in your organization, there are several scenarios where a mailbox may become disconnected from its associated Active Directory user account. This can happen when you delete or disable a mailbox using various cmdlets and tools within Exchange. In this article, we will delve into the concept of disconnected mailboxes, including archive and disabled mailboxes.

Immediate Deletion vs Retention

When you delete a mailbox using the Remove-Mailbox cmdlet with either the Permanent or StoreMailboxIdentity parameter, it is immediately deleted from the mailbox database. However, if you simply use the Remove-Mailbox cmdlet without these parameters, the mailbox will be retained for the duration of the retention period. After this period expires, the mailbox is permanently deleted (also referred to as purged). This means that both the Exchange attributes and the Active Directory user account are deleted.

Retained Mailboxes

Disabled and deleted mailboxes are retained in the mailbox database until the deleted mailbox retention period expires, which is 30 days by default. The difference between these two scenarios is that when you disable a mailbox, only the Exchange attributes are removed from the corresponding Active Directory user account, while the user account itself remains intact.

Disconnected Mailbox Types

There are two types of disconnected mailboxes: disabled mailboxes and archive mailboxes. A disabled mailbox occurs when a mailbox is disabled or deleted in the Exchange admin center (EAC) or using the Disable-Mailbox or Remove-Mailbox cmdlet in the Exchange Management Shell. In this scenario, Exchange retains the deleted mailbox in the mailbox database and switches it to a disabled state.

On the other hand, an archive mailbox is a type of disconnected mailbox that is not associated with an Active Directory user account. This type of mailbox contains mail data stored in the Exchange mailbox database, but does not have any configuration data stored in the Exchange attributes of the Active Directory user object.

Components of a Mailbox

Each Microsoft Exchange mailbox consists of an Active Directory user account and the mailbox data stored in the Exchange mailbox database. The following figure shows the components of a mailbox:

In conclusion, disconnected mailboxes can occur due to various scenarios, including deletion or disabling of mailboxes using Exchange cmdlets. Understanding the differences between archive and disabled mailboxes is crucial for effective mailbox management and retention policies in your organization.

Archive mailbox