I don't use Yahoo, but I am having trouble now with my grandfathered hotmail accounts and POP3 in my Outlook Express. 

They were working fine until about 4 or 5 days ago when suddenly I started to get prompted to add my password on each of my 2 hotmail accounts.  I have other POP3 address for here, my own site and gmail and I don't have issues with those, but recently hotmail stopped responding to my POP3.

I do know that hotmail no longer supports POP3 on free accounts, but because my accounts were pre-existing from years back, they were grandfathered in and the no POP3 does not apply to those 2 accounts.

I've written to hotmail and they wrote me back telling me to contact Microsoft about Outlook Express.  I wrote them back telling them that it's not an Outlook Express problem, it's a hotmail one because it's only affecting my 2 hotmail accounts an no others. They wrote me back again and told me to contact Microsoft about Outlook Express.  sheesh  So I'm still waiting.

"It is good to see ourselves as others see us. Try as we may, we are never
able to know ourselves fully as we are, especially the evil side of us.
This we can do only if we are not angry with our critics but will take in good
heart whatever they might have to say." - Ghandi