Thank you, but actually I asked whether you could IMPORT the stored folders into Windows Mail (Windows 10 Mail). I know how to export from WLM 2012 (and how to import into another WLM 2012). What I need to know is whether it is possible to import all these thousands of POP3 emails which are currently stored in folders on WLM 2012 on a Windows 7 laptop into Windows Mail on a new Windows 10 laptop. If I cannot import the stored emails into Windows 10 Mail then there is no point in me using Windows 10 Mail (set up as POP3) because it is all the back catalogue of stored emails which I need to refer to - and add to using POP3. I cannot seem to obtain a definite answer as to whether import of stored folders into Windows 10 Mail is possible, although some posters seem to say it isn't. If it isn't then I can't use Windows 10 Mail which might otherwise have been a choice as I need a programme which is compatible with Windows 10 and is likely to remain so in future Windows - ie Windows 11 and so on.
It is essential to me that I have a (free) email client (host) programme which can support six email accounts (at least), uses POP3, will store emails locally in folders so that I can delete from servers, and will allow me to import my existing stored emails.