Export the .eml file to a PST file,
May I suggest to export a eml file to a PST file or msg files, or export and save to a selected folder in PST.
thank you.

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Amelia Roberts commented
Several programs are available to export the EML files to a PST file, but I advise you to use the GainTools EML to PST Converter. The sophisticated features and straightforward user interface of this program define it as the most reliable solution. This program allows you to quickly convert EML files to PST with attachments easily, without Outlook. This utility's sophisticated, easy-to-use features allow technical and non-technical users. It lets users export EML files into PST format, which is available on all Outlook versions—including 2003, 2007, 2010, 2013, 2016, 2019, and others.
Visit here: https://www.gaintools.com/eml/pst/