Outlook 2016 won't sent after changing password

[CHBQT]

I've spent 3 hours searching the internet and forums and trying all the quick fixes but they don't work.



My ATT Yahoo webmail said I needed to change my password so I did, and then verified that it works. I also changed on my Iphone and it works. I followed directions to change on my Outlook (Microsoft Office Professional 2016,Outlook 2104 (Build 13929.20386), but the verifying email won't go through. I keep getting the pop up box with error "Internet Email, Enter your user name and password for the following server." I keep entering it, and it keeps popping up.

I also checked the Control Panel>Credential Manager>Window Credentials>Generic Credentials> and changed it there too.

Years ago, I recall having to go back to my ATT-Yahoo webmail and doing something to get a special code to put in this error box. I found a YouTube video about that, but my programs did not have the same options so I could not perform.

Please hellp