If you don’t want to use Apple Mail, you can still view EML files on Mac without any trouble. Apple Mail usually requires importing EML files into the app, which isn’t ideal when you only need to read the email or check its details. Since macOS doesn’t open EML files natively, using a standalone EML viewer is the easiest alternative.

To view EML files directly, many users rely on tools like MacSonik EML Viewer Pro. This type of viewer opens EML files as read-only data, showing the complete email content along with attachments and header information. You don’t need to set up an email account, convert files, or modify the original message in any way.
Read more: https://www.macsonik.com/eml-viewer/