Email issues

Alright so I have been using the "mail" that is already at the bottom of my screen. I connected it to my yahoo email address. Earlier today my email was working perfectly, but just a little while ago the little mail icon kept popping up. When I clicked to see what was wrong it had me type my password in for my email account, so I did, and it rejected it. I know I have the right password because I checked it on the actual yahoo site, and just to be safe I changed my password, and the new one still didnt work. And right after it rejects my password this pops up "This account (Yahoo!) appears to be offline due to a network problem. Do you want to try to go online now?" I am not sure what I am supposed to do because when I click yes it just brings me back to plugging in my password. I also opened the "connection doctor" and one of the connections came up red which I know means its not working but I am not sure on how to make it got green. Please help! Thanks