EMLX files can not be directly opened in Microsoft Outlook because they are a format used by Apple Mail. If you want to open an EMLX file in Outlook then you need to convert it into MSG  or  EML. You can use a third-party tool like the FixVare EMLX converter tool. Which Outlook can open directly? This is an award-winning tool to convert data in bulk without losing structure and quality.it is Restore the original structure and properties of each email after conversion. Yes, EMLX  files always need to be converted before they can be used in Outlook