Product Defect
This is caused when the option to "Proxy through clients access server" is selected in the Exchange 2013 Send Connector Properties.
Currently the only workaround it to uncheck the "Proxy through clients access server" option on your Send Connectors
Log into the Exchange 2013 "Exchange admin center" Click Mail Flow | Send Connectors
Double click each send connector to open the properties and on the general tab uncheck the "Proxy through clients access server" check box.
This issue has been verified as a defect and raised as TF00327773. This will be evaluated by our Product team for inclusion in a future release of MessageStats.
A list of “Resolved Issues” is published in the product Release Notes accompanying new releases that can be referenced to identify if a fix for this defect has been implemented. Product Release Notes are available in the “Product Documentation” area of our support portal at www.quest.com/support.
For more information on our Product Enhancements and Defects policy, see details published in our Global Support Guide available on the Quest Support portal.