I am transitioning from Exchange 2003 to Exhange 2010. In my current existing Exchange 2003 environment my storage groups (Information Stores) are physically located on an external storage array (SAN) via an ISCI connection. I initally hoped that I could simply follow the steps and prepare my environment and Install Exhange 2010 and then point it to the storage groups (information stores) on the storage array (which are currently Exchange 2003 based). After further research I am not so sure this is possible. I really don't want to move all these mailboxes. So is it possible to create the ISCI connection from my Exchange 2010 server and point it to the Exhange 2003 storage groups (information stores) and mount them as an Exchange 2010 mailbox databse???