Microsoft Exchange creates the default mailbox folders (Inbox, Outbox, Sent Items and Deleted Items) when the user first checks his mail through any of the available clients, or when the first message the exchange server delivers to this mailbox (if received before the first mail check form the mailbox owner).
These folders are created in localized language (Arabic for example) if the mailbox owner checked his mailbox through localized client (localized Outlook for example) with localized menu (not using Multi Language Pack). However, this is the case only if the user used MAPI protocol (outlook) or WebDAV (OWA); POP3 and IMAP4 clients don’t send information to the exchange server about the language of the client, thus the folders will be created using English names. Once these names are created, they keep their localized or non-localized names as permanent.

Using the shared M drive on the exchange server, the user can rename his mailbox folders to any name, using any language, he likes to.