OUTLOOK 365 has a yahoo pop up

I had to turn off outlook from automatically trying to sync.  Then I had to make a secure mail key on the att.com web site.  It is under the profile section.  Then I had to wait an hour for the yahoo time out to expire.  Then I could go into outlook and update the mail accounts password with the 16 digit mail key.  Then I had to call ATT service for them to reset the account.  I then had to wait for the yahoo time out to expire.  After that I when I logged in again it went to the yahoo pop up and prompted me for the yahoo account and password and again and I entered the account and the mail key.  It is now working.

Hi there, JanLesko. We understand that your Microsoft 365 is giving you a Yahoo prompt. We can help fix that. 

What is going on is that your email program is trying to use OAuth or what is called Open Authentication. It is doing the correct process. 

Here is a little background information for you. AT&T and Yahoo are email partners. AT&T provides the email address and Yahoo provides the email management and webmail. 

Since you are getting the Yahoo prompt, that normally means that your password could have been corrupted or needing to be reset. Let's go ahead and move in that direction. Please use the following steps to reset your password: 

1. Go to reset your password.
2. Enter your user ID and the last name associated with your ID.
3. Choose your verification method and follow the prompts.
4. Enter and confirm your new password.

After the password reset has been completed, then we can take the new password over to Outlook 365. 

Using your full email address and new password in the Yahoo prompt, it should redirect you to AT&T. Re-enter the same information and if successful, the Outlook 365 should reconnect. 

If you are unable to complete the password reset, please let us know. 

Matthew, AT&T Community Specialist

That is wonderful, JanLesko. 

We are so glad that you were able to get your Outlook365 working again. 

If there is anything else that we can do for you, please reach out to us again. 

Thanks for using the AT&T Community Forums. 

Matthew, AT&T Community Specialist

The Yahoo Mail popup has repeatedly appeared in my Microsoft outlook.com email account for six weeks. I don't want Yahoo Mail to control my Outlook Mail account. 

When I proceed through the promptings and enter the required credentials (User Name, Password) on the Yahoo screen, the following box appears saying I agree to sign into my Microsoft Outlook account with my Yahoo account. I don't want Yahoo Mail to control my Outlook Mail account.

Please tell me how to stop the popup from appearing. Thank you.

Here's the screenshot:

i am also getting this yahoo pop up to sign into outlook 365 using my yahoo credentials. I have changed the password twice now. this is continually happening on both my computers.