"Developers may share data with third parties so long as they are transparent with the users about how they are using the data", Google VP Susan Molinari wrote to the Senate Commerce Committee in a July letter.
"Using software tools provided by Gmail and other email services, outside app developers can access information about what products people buy, where they travel and which friends and colleagues they interact with the most", reports the Wall Street Journal.
Omnipresent tech giant Google told United States senators that it lets third-party apps read data from Gmail accounts and share this information with marketers, even though Google itself allegedly stopped this practice a year ago.
The senators asked whether Google was aware of "any instances of an app developer sharing Gmail user data with a third party for any purpose".
In a letter made public on Thursday, Google addresses concerns made by lawmakers over the way it allows data to be collected from its users.
Google and other tech companies are set to face the Senate next week in a hearing over data privacy. Developers also need to tell users if the app changes how it uses the data.
Senators may seek further clarity on Gmail's operations at a Commerce Committee hearing about privacy practices scheduled for September 26 with officials from Google, Apple Inc, AT&T Inc and Twitter Inc.
Next week, privacy officials from Google will join those from Apple, Amazon, Twitter, AT&T and Charter Communications for a hearing scheduled with the Commerce Committee.
The Smart Reply feature is apparently catching on.