Yahoo Outgoing Mail suddenly not working......

i am having a problem with my iphone sending email. I've had it for over a month with no problems and I'm suddenly getting an email stating that I can't send emails using the outgoing server for my Yahoo mail account. there are other similar posts but I've followed instructions to set up an app password and that didn't seem to help or perhaps it was filled out incorrectly with the wrong website name. I'm not sure but suddenly not able to send outgoing mail. As an aside, I have an Iphone SE 128GB. The error message says, 'the connection to the outgoing server 'apple.smtp.mail.yahoo.com' failed. I also tried deleting the account and setting up and that didn't work. I generated an app password on the Yahoo Security site and that didn't seem to work unless its somehow configured wrong. I'm confused as this happened out of the blue.