Save Outlook messages as EML, with Export Messages to EML add-in
Export Messages to EML is an Outlook add-in you can use to save some or all of your MS Outlook messages in EML format to use them as individual documents or import them to other eMail applications.
You don’t have to use the program as Outlook add-in but also as an individual app; even this way it is able to make the conversion of Outlook messages.
Export Messages to EML is as easy to use as selecting Outlook mail folders and the location to save converted messages. Each of your Outlook messages is saved as an individual EML file.
Note also that encrypted messages can be (hopefully) decrypted upon conversion.