Luckily this customer only has approximately 20 users all who run cached Exchange mode within Outlook 2010. As a result, their mail was stored locally on each workstation in their OST file. I went around to each workstation and exported the users mailbox to a PST file.
Next I replaced the disks and rebuild the RAID5 array, created a new NTFS partition and started the Information Store. This generated new black mailbox databases.
With Exchange 2007, you need to use the legacy Import-Mailbox cmdlet instead of the New-MailboxImportRequest cmdlet available in Exchange 2010 and Exchange 2013. Import-Mailbox requires a 32bit computer running 32bit version of Outlook. I downloaded the Exchange 2007 SP3 32bit installation which I installed on a 32bit Windows 7 workstation joined to the domain and installed only the Exchange 2007 Management Tools.
When attempting to import a mailbox it failed with the following error:
[PS] C:\Windows\system32>Import-Mailbox -Identity information -PSTFolderPath C:\pstfiles\info.pst -Verbose
VERBOSE: Import-Mailbox : Beginning processing.
VERBOSE: Import-Mailbox : Ending processing.
Import-Mailbox : Error was found for Information (firstname.lastname@example.org) because: Error occurred in the step: Approving object. An unknown error has occurred., error code: -2147221233
VERBOSE: Import-Mailbox : [information] The operation has finished.
Most resolutions on the Internet for this problem is to simply run FIXMAPI.exe from a command prompt. This however did not resolve my issue. After further research, I found that two updates released by Microsoft for Outlook 2010 cause this problem:
After uninstalling these patches, I rebooted the Windows 7 workstation and straight away I was able to import mailboxes and export.