There is an example here of finding the Conversation History folder on Exchange through EWS:
http://msdn.microsoft.com/en-us/library/hh243707(v=office.14).aspx
However, the way that it is doing this is by searching for the display name....This won't work for other languages though. For Exchange 2013, there is a Conversation History has a well known folder name so that can be used, but there is no such thing for Exchange 2010....
Is there any other way to find the folder (in Exchange 2010) without resorting to name search?