As i was protecting an Exchange 2003 (on Windows 2003 R2) from DPM 2010 (on Windows 2008 R2), i needed Exchange 2007 32-bit version of eseutil to be installed on DPM 2010 server.
i had naturally copied the eseutil from Exchange 2003, which did not work so.
So i downloded the Microsoft Exchange Server 2007 Management Tools (32-Bit), installed on a test Windows 2008 Std, 32bit (it had AD installed). i then extracted the eseutil dll and exe and copied to the DPM 2010 server.
This is where i pretty much got the idea that i needed the Exchange 2007 tools.
If you installed DPM 2007 on a Windows Server 2008 operating system, and you are protecting Exchange Server 2003 on a Windows Server 2003 computer, you must install the Exchange Server 2007 version of the eseutil.exe and ese.dll files. You can download this version from the Microsoft Exchange Server 2007 Management Tools (http://go.microsoft.com/fwlink/?LinkId=112325).