Consider the following scenario:
You are in an environment that has Microsoft Exchange Server 2010 Service Pack 3 (SP3) or a later update rollup installed.
You import an American National Standards Institute (ANSI) format personal folder (.pst) file of Russian language that has a Cyrillic encoding to a mailbox by running the New-MailboxImportRequest cmdlet.
The .pst file contains non-ASCII characters.
You open the imported file.
In this scenario, the imported folder names and contents are unreadable. The characters that are used for folder names is a garbled mix of special characters.
To resolve this issue, install Update Rollup 8 for Exchange Server 2010 Service Pack 3.
To work around this issue, import the ANSI .pst file by using Microsoft Outlook or convert the ANSI .pst file to a Unicode file before you run the New-MailboxImportRequest cmdlet.
Microsoft has confirmed that this is a problem in the Microsoft products that are listed in the "Applies to" section.