Google has confirmed anyone who has linked third-party apps to their accounts may have unknowingly allowed third-party developers to read their private emails.
With 1.4 billion users Gmail is the most popular email service, however Google says the practice is not against its policies., reported the BBC.
When using the service users are asked to grant permission when connecting third-party tools such as travel planning and price comparison which gives permission to read and manage emails.
Several companies such as Edison Software and eDataSource Inc have confirmed they had read emails in order to improve their services.
Only companies checked by Google would be able to access messages and users would have had to grant permission when they agreed to the terms and conditions of third-party tools.
Late night work.
Google says users can access the Secutiry Check-up page to see linked apps and change security settings if they would like to stop sharing data with certain apps.