Hey, there are various method to transfer EML file to Outlook PST with attachments, it depends the users whichever they will choose the way to complete the conversion. Manual process can be challenging, so I recommended to choose the BitData Migration EML Converter on any OS editions. The software permits to convert bulk EML files to various email formats like OLM, MBOX, PST, PDF, Office 365 and many more. The software has a simple GUI interface to easily understand the complete process of the conversion. It provides the dual options to easily load the EML files and also gives the demo version that permits to convert first 25 EML files for free.