Mac Mail not downloading email.

I'm using Mac Mail and all of a sudden 1 of my email accounts won't download email any more. It's one of 2 GoDaddy accounts I have, the other one works fine, but this one isn't downloading email. Using the connection doctor and watching the download progress, it indicates it IS downloading email, but it doesn't actually download. I can check the email through the online web server and see mail in the account, but it won't actually download, which is tremendously frustrating and incredible inconvenience. And this JUST started happening this morning. No issues with this last night or previously. I've also REBUILT the email box, nothing. Any answers here?