I use Thunderbird and there we many posts on their forum from people struggling with the transition. It turns out Cox had posted the wrong Yahoo server information in their instructions. My wife still cannot get email to work with Outlook. What a disaster. It seems that Cox was oblivious to the fact that many people use various email clients and thought everyone was just going to use Yahoo webmail. All that time to prepare and they failed miserably. But then Cox email support has been nonexistent for years. Maybe Yahoo will actually block some phishing and spam that Cox was unable to do.