Apple has announced that third party applications will need application specific passwords for iCloud access from next month.
What is means is that people who want to use third party apps with iCloud from next month will have to enable two factoir authentication, you can see more details below.
Beginning on 15 June, app-specific passwords will be required to access your iCloud data using third-party apps such as Microsoft Outlook, Mozilla Thunderbird, or other mail, contacts and calendar services not provided by Apple.
If you are already signed in to a third-party app using your primary Apple ID password, you will be signed out automatically when this change takes effect. You will need to generate an app-specific password and sign in again.
This new requirement for applications specific passwords will come into force on devices from the 15th of June 2017.
Source MacRumorsFiled Under: Apple