Those two names are the server names for your mail -- they are the machines your software has to check to (POP) and send (SMTP) messages in the e-mail protocol.
Those names are almost certainly correct; do nothing to them.
They are also Yahoo's machines, so don't go to Apple to ask how to fix them.
The password they are asking about is the one for that account -- the yahoo account.
(I am assuming you have a yahoo.com e-mail address?)
Mitch
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