Thanks for including the complete error message. It makes troubleshooting
so much quicker and easier.
You have a couple of things wrong in your settings.
First, Go to Tools, Accounts, select that mail account, Properties, Servers.
Make sure that "Log on using Secure Password Authentication" is not enabled.
That alone may fix the problem you were having. However your port/SSL
settings don't agree with the latest guidance from Yahoo, see
http://help.yahoo.com/l/us/yahoo/mail/classic/mailplus/pop/pop-08.html
In particular, note step 10.
By the way, all the responders here (including myself) are unpaid volunteers
who donate their time and expertise to help fellow users. I've reviewed
my previous post and I don't see what part you might find objectionable.
I was merely sharing my general findings that I have learned over the past
3+ years while resolving thousands of technical issues with Windows Mail.