If you are unable to send using smtp.mail.yahoo.com but it does work with the gmail outgoing server, you might want to ensure the username is using the Cox.net.
It is. I sent some test emails yesterday and they went through but looked like they were sent from the old cox account not the new xxx@cox.net account.
I understand. If you've set all of the servers correct and the account has migrated, then at this point Yahoo.com is processing the mail entirely. I wish I had more to offer. You can contact Yahoo at 866 562 7250. I hope this helps and thank you for your patience.
