Many times administrators are called for help by users whose maibox folders are duplicated. There have been a great number of Microsoft PSS cases for this problem, as once a folder with an incorrect name becomes a default mailbox folder, it cannot be deleted or renamed, therefore the user calls for support.
There is a distinction between the mailbox folder types, as follows :
1. Default mailbox folders: Inbox, Outbox, Sent Items, Deleted Items. These are created by the Information Store the first time a MAPI of WebDAV client logs on, or when a mail is first delivered to the mailbox. The Information Store creates the folders with localized names, depending on the client local language, and sets the PR_LOCALE_ID Mapi property on the mailbox to reflect this locale setting.
2. Special Outlook folders:Calendar, Contacts, Drafts, Journal, Notes and Tasks. These are generated by CDO (Collaboration Data Objects) at the first client connection (not necessarily MAPI or WebDAV) with localized names, depending on the client language. The client can also be a mobile device, or a CDO application.
If the mailbox folders have been created in another language, the Outlook client cannot be used to rename them individually. An administrator can use the MFCMAPI tool (http://mfcmapi.codeplex.com/) to rename or delete these folders.
There are also two Outlook switches that can be useful :
Outlook /resetfolders will restore the missing default folders (use this if they were not present or if you deleted them with a MAPI analyzer)
Outlook /resetfoldernames will reset the default folder names to the names in the current Office interface language.