The Microsoft articles below describe how to configure the E-mail Router for use with Exchange 2010. Note that Update Rollup 8 is required for this.
Exchange Impersonation needs to be configured for the account used to connect to the Exchange Server to collect mail even if the account used is the Domain Administrator.
http://blogs.msdn.com/crm/archive/2009/12/21/how-to-configure-microsoft-…