To control which applications have access to your Yahoo account, first sign in at https://edit.yahoo.com/mc2.0/eval_profile
After that you can choose Manage Apps and Website Connections under Sign-In and Security:
Once you’ve clicked Manage Apps and Website Connections you should see a page that lists your authorized applications:
When you first allow access to an application, Yahoo should send you an e-mail that says something like:
Hello,
You agreed to share your Yahoo! information with Macworld. You can manage who sees your activities on Macworld. If you did not agree to share your information, stop sharing.
Regards, Yahoo! Account Services
If the first link doesn’t work for you, you can also try this one:
https://api.login.yahoo.com/WSLogin/V1/unlink?.intl=us
