I suggest you use Mac OLM to Gmail Converter which allows users to save data in various file formats like EML, EMLX, Zimbra, MSG, HTML, etc. The software manages OLM items such as contacts, calendar, emails, tasks, notes and folders, subfolders, etc. The tool allows the user to check the preview of the email with the attachment and full header details. [table][tr] [td]
https://www.kdetools.com/mac/olm/gmail/[/td][/tr][/table]