There are no error messages associated with this issue.
This issue is due to an issue with the product when importing Japanese into Alta Archiving that have no email address associated with the 'From' field of the message.
As one example: Messages like this can occur when the Author is disabled in Exchange and the associated email address is removed. When the item is subsequently exported to PST and then imported into Alta Archiving using either the 'Import Data' feature in the Manage Portal or via a Data Management request the result will the result can be oddly displayed Author information in Alta eDiscovery.
This issue is resolved in the December 2023 release of Alta Archiving. Newly ingested items after the December 2023 release should not have this issue.