After having the T-mobile HTC One for nearly 2 years, my mac mail has inexplicably stopped letting me send emails. I've tried deleting it and then adding it again, but I keep getting the message "your outgoing server does not support authentication. Please verify your outgoing server settings" - I am able to manually set it up, but still cannot send mail, only receive. I'm hoping someone else has had this problem & can shed some light on how to solve this issue. Thanks!