I have been using Windows Live Mail 2012 on my Windows 8.1. I have decided to upgrade OS to Windows 10

I want to use the new mail client included with Win 10

I only use Live Mail 2012 with private (non-MS) POP3 email servers, I do not use any MS accounts. So, all of my email and contacts are stored locally on the machine.

How do I get all of these contacts and emails, including quite a few folders of essential archived emails, into the new client?

I have looked for support, but everything I can find involves recovering the emails/contacts from a MS server, but not from locally stored data.

Any help gratefully received. Thank you.