If you receive error ‘acces denied 0xe0008488’ when backing up your exchange databases using Symantec Backup Exec, check the version of exchange management tools on both server. The easiest way to do this:
1) On each server (your exchange server and your backup server) browse to Program files\Microsoft\Exchange server\Bin and locate file name ESE.dll.
2) Right click on the file and click the tab named version.
3) Both versions should be the same. If not one may have no service pack installed and the other without or one may have a higher service pack installed then the other.
Arrange to upgrade the server if different with the same service pack. Downloads of Exchange Management tools can be located at http://www.microsoft.com/download/en/details.aspx?id=11876
Also, check that:
1) You are not using the administrator account when backing up via backup exec. Create a new account e.g. backupexec
2) Ensure the backupexec account has a mailbox and is not hidden from the GAL
3) Backupexec account must be member of the Domain admin group and Local Admin.
4) Account must be Exchange Full Administrator.
5) Ensure backup services use the backupexec account
If the above does not resolve your issue, could be related to disconnected mailboxes on your Exchange 2007 server which do not have the correct permissions set. If you wish to remove the disonnected mailboxes, visit the below link. Note that your disconnected mailboxes folder within your Exchange 2007 console may be empty. You will need to run a command for them to appear. Command can be found at below url: