MailtoX Desktop can easily save Outlook email messages as EML files:
Outlook from the Email Source list at the left
2. Select the folder that you want to export from Outlook
3. Select Mime (*.eml) from the Email Targets at the right
4. Select the
target folder and whether to replicate Outlook’s folder structure at that folder
5. Press on
Start. The selected folders will be processed and the messages saved to disk as EML files.