Assume that Microsoft Office SharePoint Server 2007 is running on a Japanese version Windows Server 2008 R2 server. In this situation, no search results return when you perform a search for existing Japanese characters in .eml files that are located in a document library.
To resolve this issue, apply the following update:
2512780 Description of the Windows SharePoint Services 3.0 hotfix package (Sts-x-none.msp): April 26, 2011
2512781 Description of the Office SharePoint Server 2007 hotfix package (coreserver-x-none.msp): April 26, 2011
Microsoft has confirmed that this is a problem in the Microsoft products that are listed in the "Applies to" section.