Apps such as Edison Mail are gathering data under the guise of providing personalized features, but then turn around and sell this information to big business.
Two years after it was revealed that Google allows third-party companies to read the emails in users' Gmail accounts, more apps have been found to be doing the same when used with any email account.
The best-known of these is Edison Mail, which is an email client for both Mac and iOS. It has time-saving features such as providing one-click buttons for the people users most often email. Similarly to how iOS provides suggested next-word responses, Edison Mail prompts users with complete and appropriate canned responses.
Edison Mail's developers have been clear that this is achieved by parsing users' emails to build these lists, and offer relevant automatic responses. However, it has not said that it then uses that data for its own profit.
According to research done by Motherboard, the Edison Mail company sells products to finance, travel and e-commerce customers that is derived by scraping users' emails.
Edison's website explicitly states that data is collected from users, and it extensively details all the use that users' agree to by signing up to the service. At no point, however, does it say that it will sell this data.
It does refer repeatedly to service providers that it calls "partners."
"These service providers are authorized to use your information only as necessary to provide their services to us," it says.
Motherboard reports having obtained a document from the JP Morgan financial services company, which says that data is bought from Edison for the purpose of helping companies make investment decisions.
The document reportedly refers explicitly to Edison Mail as the source of data.
"[The data features] consumer purchase metric including brand loyalty, wallet share, purchase preferences etc," it says.
Edison has not responded to questions from Motherboard. However, after publication of that research, Edison has released an updated blog about its working practices.
"To keep our Edison Mail app free, and to protect your privacy by rejecting an advertising-based business model," it says, "our company Edison Software, measures e-commerce through a technology that automatically recognizes commercial emails and extracts anonymous purchase information from them. Our technology is designed to ignore personal and work email, which does not help us measure market trends."
"We do not participate in any ad targeting of our users and do not allow others to do ad targeting of our users," it continues.
The Motherboard research also reveals that email add-on services including Slice and Cleanfox sell data products to corporate clients based on user's emails. Cleanfox's parent company, Foxintelligence, did respond to Motherboard.
"From a higher perspective, we believe crowd-sourced transaction data has a transformational power both for consumers and for companies and that a marketplace where value can be created for both sides without making any compromise on privacy is possible," Florian Cleyet-Merle, Foxintelligence Chief Operating Officer said.
Updated: 13:10 ET with published comments from Edison.