To import EML emails into an Outlook 365 account, drag and drop the EML files directly into an Outlook folder. Alternatively, use third-party tools like VSPL EML to Office 365 Migrator to streamline the process by selecting EML files and migrating them directly to the desired Outlook 365 mailbox.

https://www.vartikasoftware.com/product/vs-eml-to-office365-converter.html