This article explains how to check other email accounts through your web-based Yahoo Mail account by syncing Yahoo Mail with compatible email providers, including Gmail, Outlook, and AOL. It also includes instructions for syncing with Yahoo Mail Basic.
If you have multiple email addresses through more than one email provider, you'll see all of your incoming messages in Yahoo Mail. Learn how to sync your other email addresses with Yahoo so you can get all of your email in one place.
To sync other email providers with your Yahoo Mail account:
Select the gear in the top right corner of Yahoo Mail, then select More settings.