We are upgrading from Exchange 2007 to Exchange 2010. We have some mailboxes on Exchange 2007 and some on Exchange 2010. Our SPAM appliance points to the Exchange 2007 server. If I point the SPAM appliance to our Exchange 2010 server will the users still on Exchange 2007 get their e-mail? Is the bridge joining Exchange 2007 to Exchange 2010 bi-directional? The bridge is the default bridge created when Exchange 2010 was installed. Thanks!!!