Outlook desktop client only supports the PST format. That's why you can only import PST files directly. However, some exception methods are available to import EML files to Outlook. Such as:-
Import the EML file into an email client that supports PST format: You can import the EML file into an email client like Microsoft Outlook and then use the email client's export function to save the imported emails as a PST file.
Use a third-party email conversion tool: Several tools can convert EML files to PST format. Some examples include "Regain EML to PST Converter." Why have we suggested this tool? Because it has all the advanced features and algorithms. At the same time, it's suitable for non-technical users also.
Use a manual process: You can manually convert the EML file to PST format by opening the EML file in an email client like Microsoft Outlook and then using the email client's save function to save the email as a PST file.
Regardless of which method you choose, keep in mind that the conversion process can be complex and may require some technical expertise. If you are not comfortable with these methods, consider seeking the assistance of a professional.