When performing a scheduled MS Exchange mail level backup set, the following error message is received in the backup report:
Error YYYY/MM/DD hh:mm "DOMAIN\Administrator" might have insufficient permissions to the mailbox
The message suggests that the backup software had failed to connect to the MS Exchange database via MAPI due to permission issue.
To resolve the issue, please ensure that the "Log on" account of the backup software scheduler service has sufficient permission right to access the MS Exchange database.
Instead of "Local System" (which is used by default), try running the backup software scheduler service with a Windows account that has sufficient permission right to access the MS Exchange database (the account you mentioned that successfully started the manual mail level backup). You could do so by following the instructions below:
1. Open [Control Panel] -> [Administrative Tools] -> [Services] -> [Online Backup Scheduler] -> [Log on]
2. Select the [This Account] option
3. Enter the Login Credentials
4. Restart the [Online Backup Scheduler] service