PST files are not assigned to users automatically after the scanning runs on the PST Export UNC path.
To automatically assign PST files to users when using the PST Export module, you must use the user’s primary SMTP address or email address or SAMAccount Name in the file name (in the format below), and then run the Scan on the PST Source link from the Links screen.
Here are the supported PST file name formats for auto-assignment:
Note: In a case when SAM Account Name exists in multiple domains that are enabled in Archive Shuttle, PST is not assigned to an owner and you will see entry below in the PST export module log file:
WARN|GetUserBySAMAccountName(PstExportScanDirectoryResultProcessor.cs:97)|More users with SAMAccountName [“samaccountname”], skipping auto assignment of PST owner