Please post only one thread per issue.
You should have gotten an error message. Right-click on it, copy,
then paste it into a reply here. It contains important diagnostic
information that I need to see in order to make an informed
diagnosis. My guess is that you are trying to enter the username
and password for a free Yahoo account. For the most part,
free Yahoo accounts do not have POP access, only web access.
If you need additional advice on this, reply back.