Hi Lucy

What happens when you try to access your Yahoo email account? Is there any error message?

Hi Lucy, if this is a problem signing in through AT&T, you may need to deactivate some content blocking add-ons for the AT&T site. In particular, some users reported having to make site exceptions using the toolbar buttons for the AdBlock Plus and DuckDuckGo Privacy Essentials extensions while on the AT&T page. If you don't see all your extension buttons on the main toolbar, try the Extensions button (puzzle piece) drop-down list. See: Manage your extensions using the extensions button in the toolbar.