Hello,
we have found a special bug, known in the Exchange 2013 CU2 and CU3, CU1 was ok. And all other Exchange Versions, who's have just EWS like 2007 and 2010 are also ok.
We search from extern Email with the Operation FindItem with the Element Restriction for filter Emails. (message:ToRecipients and
message:CcRecipients).
Thank for a response
Bernd