All of a sudden, I can't send emails with my HTC One phone

 I am a Verizon Yahoo email customer.  My phone stopped sending emails.   I try to send an email  and I get a message that says "unable to send mail - account settings are incorrect."  I then go to the settings, enter them, they authenticate, I try to send an email and get the same error.  My email works fine on my laptop and on-line, just not on my phone.

I've had this issue for a while now, but I used to be able to uninstall the updates and mail would work again.  Now there's no option to uninstall the updates so I'm stuck.

Any ideas?