Whenever you experience frequent Yahoo mail app crashes or unusually slow performance, it is time to check if your version of Yahoo Mail has been updated. Due to an internal matter at Yahoo, all you need to do is uninstall the app and reinstall it. If your Yahoo Mail slow today, ensure your device is correctly connected to the internet. If the problem occurs from a lack of or poor internet connectivity, check your network connection and check the App Permissions settings to make sure Yahoo Mail has been given adequate permissions. Furthermore, if the mobile number is changed or if two-step verification is enabled, Yahoo sign-in problems can occur.