Error Message

Final error: 0xe000038a - The specified Logon Account credentials do not have the necessary Powershell permissions that are needed to complete the job. Review the credentials to ensure that it has the Exchange Organization Administrator role and sufficient rights. Final error category: Resource Errors

For additional information regarding this error refer to link V-79-57344-906

Trust relationship between the Backup Exec Server and the Exchange Server is broken.

On the Exchange Server, launch the Backup Exec Agent Utility, click on the Publishing Tab and then Change Settings.  Click on Publishing, highlight the Backup Exec Server and click on Remove.

Go back to the Backup Exec Server and from the Backup Exec Console, Backup and Restore Tab, right click on the Exchange Server and click on Establish Trust. This will re-establish the Trust relationships between the two servers and will also re-add the Backup Exec Server into the Backup Exec Agent Utility.
 

Backups should now be successful.