The mailbox default folders like Inbox or Sent Items are labeled depending on the locale settings of the mailbox.
Mailbox users are able to change the default user names by changing the primary language of the Office setup and starting Outlook with the command line parameter /resetfoldernames.
The same can be achieved by the Exchange Administrator by running the Exchange cmdlet Set-MailboxRegionalConfiguration.
When moving mailbox content to a new Exchange mailbox using a PST export/import approach it is important (besides other things) that the export and import mailbox locale match. Otherwise, you will end up with new folders being imported into the target mailbox. Folders are being mapped by the folder name during import.
Example
The following screenshot shows the default folders of the mailbox in the locale de-DE.
The regional configuration settings can be checked on the Exchange Server.
[PS] C:\>Get-Mailbox askywalker | Get-MailboxRegionalConfiguration | fl
RunspaceId : f739bd99-9940-4dcf-abd5-6de080ac312d
DateFormat : dd.MM.yyyy
Language : de-DE
DefaultFolderNameMatchingUserLanguage : False
TimeFormat : HH:mm
TimeZone : W. Europe Standard Time
Identity : contoso.com/Test/Anakin Skywalker
IsValid : True
ObjectState : New
Changing the default folder names to en-US is straight forward.
[PS] C:\>Get-Mailbox askywalker | Set-MailboxRegionalConfiguration -LocalizeDefaultFolderName:$true -Language en-us
The changes are reflected in Outlook without restarting Outlook.
[PS] C:\>Get-Mailbox askywalker | Get-MailboxRegionalConfiguration | fl
RunspaceId : f739bd99-9940-4dcf-abd5-6de080ac312d
DateFormat : M/d/yyyy
Language : en-US
DefaultFolderNameMatchingUserLanguage : False
TimeFormat : h:mm tt
TimeZone : W. Europe Standard Time
Identity : contoso.com/Test/Anakin Skywalker
IsValid : True
ObjectState : New
When you now try to revert the configuration to de-DE receive an error that the locale does not match the current date and time format. This is even more interesting that the cmdlet was not complaining about the same issue when converting to the en-US locale.
[PS] C:\>Get-Mailbox askywalker | Set-MailboxRegionalConfiguration -LocalizeDefaultFolderName:$true -Language de-de
DateFormat "M/d/yyyy" isn't valid for current language setting "de-DE". Valid formats include "dd.MM.yyyy, dd.MM.yy, yyyy-MM-dd, dd. MMM. yyyy".
+ CategoryInfo : NotSpecified: (contoso.com/Test/Anakin Skywalker:ADObjectId) [Set-MailboxRegionalConfiguration], DataValidationException
+ FullyQualifiedErrorId : [Server=CT01,RequestId=3bcd1191-c547-45ec-a7ad-dc5e8a1e34db,TimeStamp=05.02.2014 11:19:11] [FailureCategory=Cmdlet-DataValidationException] 2161B69F,Microsoft.Exchange.Management.StoreTasks.SetMailboxRegionalConfiguration
+ PSComputerName : CT01.contoso.com
The TimeFormat "h:mm tt" isn't valid for current language setting "de-DE". Valid formats include "HH:mm, HH:mm' Uhr'".
+ CategoryInfo : NotSpecified: (contoso.com/Test/Anakin Skywalker:ADObjectId) [Set-MailboxRegionalConfiguration], DataValidationException
+ FullyQualifiedErrorId : [Server=CT01,RequestId=3bcd1191-c547-45ec-a7ad-dc5e8a1e34db,TimeStamp=05.02.2014 11:19:11] [FailureCategory=Cmdlet-DataValidationException] D603E2E8,Microsoft.Exchange.Management.StoreTasks.SetMailboxRegionalConfiguration
+ PSComputerName : CT01.contoso.com
To successfully convert back to the de-DE locale it is required to specify a valid date and time format for the target locale.
[PS] C:\>Get-Mailbox askywalker | Set-MailboxRegionalConfiguration -LocalizeDefaultFolderName:$true -Language de-de -DateFormat dd.MM.yyyy -TimeFormat HH:mmWhen setting the regional time zone information, the time zone name must be used. A Granikos FAQ post lists the available time zones.
