As a tool, I want to suggest you to use MailsDaddy EML to PST converter for migrating multiple EML data to Outlook PST at once. it able to maintain folder hierarchy, data properties and Metadata without losing or damage any data. Using this tool, you can see the display of loaded EML files & folder in the right side corner. The tool allows you to export EML to PST as well as other given formats.
To get familiar with the tool features, you can use its demo versions.