MailsDaddy Free EML Viewer
To view EML data files in Windows OS you can use the MailsDaddy Free EML Viewer application. This GUI tool has several features to open and read the data files. It supports all EML/EMLX based email clients such as Windows Live Mail, Outlook Express, Zoho, Thunderbird, Apple Mail, etc. If you want to go further process then you can also upgrade the tool and convert the EML data files into multiple mail formats.
For more detail: https://www.mailsdaddy.com/free-eml-viewer/