Microsoft Exchange Server 2013 - Managing mailboxes: The essentials (part 3) - Restoring on-premises users and mailboxes

Occasionally, you might want to hide a mailbox so that it doesn’t appear in the global address list or other address lists. One reason for doing this is if you have administrative mailboxes that you use only for special purposes. To hide a mailbox from the address lists, follow these steps:

Address lists, such as the global address list, make it easier for users and administrators to find available Exchange resources, including users, contacts, distribution groups, and public folders. The fields available for Exchange resources are based on the type of resource. If you want to add more values that should be displayed or searchable in address lists, such as an employee identification number, you can assign these values as custom attributes.

Exchange provides 15 custom attributes—labeled Customer Attribute 1, Custom Attribute 2, and so on through Custom Attribute 15. You can assign a value to a custom attribute by completing the following steps:

When you disable or delete a mailbox, on-premises Exchange retains the deleted mailbox in the mailbox database and puts the mailbox in a disabled state. There is, however, an important distinction between disabling and deleting a mailbox, and this difference affects recovery. When you disable a mailbox, the Exchange attributes are removed from the user account and the mailbox is marked for removal, but the user account is retained. When you delete a mailbox, the Exchange attributes are removed from the user account, the mailbox is marked for removal, and the user account itself is either marked for deletion or deleted entirely. Additionally, with either, if the mailbox has an in-place archive, the in-place archive will also be marked for removal. However, if the mailbox has a remote archive, the remote archive is removed permanently.

Disabled and deleted mailboxes are referred to as disconnected mailboxes. Disconnected mailboxes are retained in a mailbox database until the deleted mailbox retention period expires, which is 30 days by default. Deleted users may be retained as well.

In Exchange Admin Center, you can find disconnected mailboxes and reconnect them by completing these steps:

You can find all disabled mailboxes in an on-premises Exchange organization by entering the following command:

Get-MailboxDatabase | Get-MailboxStatistics | Where { $_.DisconnectReason
-eq "Disabled" } | ft DisplayName,Database,DisconnectDate,DisconnectReason

Or you can find disabled mailboxes in a particular database using the following command:

Get-MailboxStatistics -Database DatabaseName | Where { $_.DisconnectReason
-eq "Disabled" } | ft DisplayName,Database,DisconnectDate,DisconnectReason

If you find that you need a mail-enabled or mailbox user account that was deleted, you may be able to restore the deleted account. For on-premises Exchange, you can restore user accounts from Active Directory. When Active Directory Recycle Bin is enabled, you can recover deleted objects using Active Directory Administrative Center (as long as the deleted object and recycled object lifetimes have not expired).

In Active Directory Administrative Center, select the Deleted Object container to see the available deleted objects. When you select a deleted user by tapping or clicking it, you can use the Restore option to restore the user to its original container. For example, if the user account was deleted from the Users container, the user account is restored to this container. Once the user account is restored, you can restore the Exchange settings and data. You can use Connect-Mailbox to connect the user account to its disconnected mailbox.

When you connect a disconnected mailbox using Connect-Mailbox, you associate the mailbox with a user account that isn’t mail-enabled, which means the user account cannot have an existing mailbox associated with it. Connect-Mailbox has a slightly different syntax for standard mailboxes, shared mailboxes, and linked mailboxes. For standard mailbox users, the basic syntax for Connect-Mailbox is:

Connect-Mailbox -Identity ExchangeId -Database DatabaseName -User ADUserId
-Alias ExchangeAlias

where ExchangeID identifies the disconnected mailbox in the Exchange organization, DatabaseName is the name of the database where the disconnected mailbox resides, ADUserID identifies the Active Directory user account to reconnect the mailbox to, and ExchangeAlias sets the desired Exchange Alias. Consider the following example:

Connect-Mailbox -Identity "Thomas Axen" -Database "Sales Database"
-User "Thomas Axen" -Alias ThomasA

This example reconnects the Exchange mailbox for Thomas Axen with the related user account in Active Directory and sets the Exchange alias as ThomasA. The alias is combined with the user logon domain to set the User Principal Name (referred to in the UI as the User Logon Name). The User Principal Name must be unique within the organization. If another user account has the same User Principal Name, you’ll see a warning about a user name conflict. You will need to resolve this conflict before you can connect the mailbox.

When you disable or remove an archive mailbox from a mailbox, the archive mailbox is disconnected from the source mailbox, marked for deletion, and retained according to the retention settings. To connect a disabled archive mailbox to the original source mailbox, you use the Connect-Mailbox cmdlet with the -Archive parameter.

Although Connect-Mailbox has restrictions, you can connect a disconnected mailbox to a user account that already has a mailbox. When you restore the mailbox, its contents are copied into the target user’s existing mailbox while the deleted mailbox itself is retained in the mailbox database until the retention period expires (or it is purged by an administrator).

You use New-MailboxRestoreRequest to restore mailboxes to accounts with existing mailboxes. The basic syntax is:

New-MailboxRestoreRequest -SourceMailbox MailboxID -SourceDatabase
DatabaseName -TargetMailbox ExchangeID

where MailboxID is the display name or GUID of the disconnected mailbox to restore, DatabaseName is the name of the database where the disconnected mailbox resides, and ExchangeID is an Exchange alias or name for the account where the mailbox should be added. Consider the following example:

New-MailboxRestoreRequest -SourceMailbox "Karen Berg" -SourceDatabase
"Marketing Database" -TargetMailbox "Dag Rovik"

You can restore archive mailboxes to users with existing accounts as well. Use the -TargetIsArchive parameter as shown in this example:

New-MailboxRestoreRequest -SourceMailbox "In-Place Archive - Karen Berg"
-SourceDatabase "Marketing Database" -TargetMailbox "Dag Rovik"
-TargetIsArchive