Why is Juno.com labelled supicious by Norton?

For the last few days, every time I try to log into www.juno.com to see my email, Norton blocks it with a warning that the site is suspicious. This is a major email provider, why is this happening? I understand that people get viruses through email, but doesn't that happen with all providers? Is it because of the very abnormally high number of video streaming ads on the web mail site?