In this case of yours I would like to suggest you the following solution
Consider using Exchange WebService which can be consumed by .NET client application through ASMX webservice or WCF manage client proxy. Exchange Web Service (EWS) provides rich programming interfaces for client applications to interact with Exchange Server for retrieving and updating information.
There is a library (Exchange WebServices .NET) available that can help you out:
http://www.independentsoft.com/exchangewebservices/index.html
Hope the available provided solution could help you out in reading
Exchange mailbox.
Regards,
Christina