Migrating EML files to Office 365 usually involves converting or importing the email data into a format that can be transferred to Microsoft 365. When there are only a few emails, a manual approach may be sufficient. For larger collections, dedicated conversion software can make the process more manageable. SysTools EML Converter can be used to convert EML files into supported formats such as PST, which can then be used as part of an Office 365 migration workflow. The exact process depends on the size of the mailbox and the migration method being used. It’s important to test the process with a small set of emails before migrating the complete collection.