Backup Exec Remote Agent is installed on Exchange 2007 Server. (Remote Agent version must match Backup Exec version)
MS Exchange 2007 Management Tools are installed on the Backup Exec Server.
MS Exchange Server MAPI Client is installed on Exchange 2007 Server. (Ver 1.2.1 or higher http://www.microsoft.com/downloads/details.aspx?FamilyID=e17e7f31-079a-43a9-bff2-0a110307611e&DisplayLang=en)
Backup Exec “Logon Account” is a member of Domain Admins and is a Local Admin on the Exchange 2007 server.
Backup Exec “Logon Account” must also have the “Exchange Server Admin Role” assigned from the Exchange Management Console.