Dear Steve Wickham MSFT,
Thanks for using Microsoft products and posting in the community.
I understand that your inability to add your AOL mailbox is causing you problems and I understand how you feel.
The first thing I need to explain to you is this: to access your Yahoo Mail account (AOL Mailbox) in a third-party application, you need to generate and use application passwords. These passwords are randomly generated codes that allow non-Yahoo applications to access your Yahoo account. You will need to provide this code once to sign in with the third-party email application.
Here are the steps to generate and manage passwords for third-party applications:
1. Log in to your Yahoo account.
2. Go to your account security settings.
3. Select Generate Application Password.
4. Follow the prompts to generate a password.
5. Enter the generated password into the third-party application.
If you need detailed instructions, please see the link below:
Disclaimer: Microsoft provides no assurances and/or warranties, implied or otherwise, and is not responsible for the information you receive from the third-party linked sites or any support related to technology.
I hope this information has been helpful to you. If you have any questions, please let me know and I will be happy to assist you further.
Thank you for your patience and understanding.
Have a great day.
Best Regards,
Linda.L-MSFT | Microsoft Community Support Specialist
