GoogleÂ announced that users can opt to disable access for apps that use â€œinsecure sign-in technology.â€
Apps that donâ€™t comply with the latest security standards may be blocked by default, in which case the user will receive a â€œPassword incorrectâ€ error when signing in using a third-party application or service. The user can either upgrade to a â€œmore secureâ€ app or tick the option â€œAllow less secure apps.â€
The list of affected apps includes the mail app on iPhones and iPads with iOS 6 or below, the mail app on Windows phone prior to Windows Phone 8.1, some third-party mail apps on Android and desktop mail clients such as Outlook or Thunderbird.
Accounts with two-factor authentication enabled are not influenced by this change, but users may be asked to create app-specific passwords. ReadÂ this guide if you want to know how toÂ set up two-factor authentication for Google.