Exchange 2010 Rbu Login Issue

[wastedlife]

Hello, we have Retrospect 7.7.562 backing up an Exchange 2010 server running on Windows Server 2008 R2, among others. Our issue is that it cannot login as the user account created for backup to either the Exchange Database or Exchange Mailboxes. However, both work for the default domain administrator. This works as a temporary workaround for now, but need to use the backup user due to the administrator password changing frequently. The user account is a member of Domain Users, Domain Admins, Backup Operators, and Enterprise Admins, as the Exchange guide recommends. This user also worked for the Exchange 2003 server that we had previously. When we use "Login As.." in Retrospect for the volume, there is no error that we see (might go by too quickly), but the volumes appear empty. If we use "Login As.." to enter the "administrator" account, it works with no issues.