Is there any documentation for configuring Windows 10 Mail?

I have two accounts and would prefer to store all received and sent email on my PC.

My primary account is with Yahoo and my ISP.

My second account  uses a POP3 server through my former ISP. I still receive messages even though I the account should not work. There is no webmail access. What appear to be the relevant configuration options are disabled. What must I do to make this work?

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