How to restore an Inactive Mailbox
*This will restore the contents of an Inactive Mailbox to an existing mailbox. Inactive mailbox will be kept intact.
Exchange Online Powershell must be used you cant use Exchange admin center.
1. Run the following command to get information on inactive mailboxes.
Get-Mailbox -InactiveMailboxOnly | FL Name,DistinguishedName,ExchangeGuid,PrimarySmtpAddress
2. This command creates a variable that contains the properties of the inactive mailbox.
*Use the value of the DistinguishedName or ExchangeGUID to identify the inactive mailbox.
$InactiveMailbox = Get-Mailbox -InactiveMailboxOnly -Identity <identity of inactive mailbox>
3a. This command restores the contents of the inactive mailbox to and existing mailbox or top-level folder.
Mailbox: New-MailboxRestoreRequest -SourceMailbox $InactiveMailbox.DistinguishedName -TargetMailbox newemployee@contoso.com -AllowLegacyDNMismatch
Top-level folder: New-MailboxRestoreRequest -SourceMailbox $InactiveMailbox.DistinguishedName -TargetMailbox newemployee@contoso.com -TargetRootFolder "Inactive Mailbox" -AllowLegacyDNMismatch
3b. This command restores the contents of the inactive mailbox to and existing mailbox. Contents will be merged into corresponding folders.
New-MailboxRestoreRequest -SourceMailbox $InactiveMailbox.DistinguishedName -TargetMailbox newemployee@contoso.com -AllowLegacyDNMismatch