Recently my email client, which sends and received via a GoDaddy workspace email account, stopped being able to send emails. Receiving on pop.secureserver.net was fine but smtpout.secureserver.net was suddenly not working. I reinstalled the account several times but always got the message "Username or password not verified." GoDaddy support, always helpful, reviewed my settings and found nothing wrong. Online searches suggested an Mac OS Sierra email client bug, but no solution. In the midst on this agony, I suddenly remembered another GoDaddy user who had a similar problem and had been prompted (by GoDaddy) to change their email workspace password (not the password to their GoDaddy account, two different entities). I logged into my GoDaddy workspace email dashboard and changed my password. Voila! Smtpout was fine again. Hope this helps others!