Gmail more likely to flag Republican fundraising emails as spam, study finds

Google's campus in Mountain View, CA. Source: WikikCommons

Listen to this story (4 minutes)

  • Gmail has an estimated 1.5 billion users
  • Gmail provides no information on how they identify "spam"

A study from researchers at N.C. State University finds that Gmail marked 59% more Republican fundraising emails as spam than Democratic ones during the 2020 election.

Researchers examined more than 100 accounts and 318,000 emails for Gmail, Outlook, and Yahoo Mail from May through November 2020. The emails came from the campaigns of both presidential candidates plus 78 Senate candidates and 156 House candidates from both political parties.

“We observed that the [spam filtering algorithms] of different email services indeed exhibit biases towards different political affiliations,” the researchers concluded. They noted that none of the three email platforms provide “any transparency on their internal workings,” and that a “growing body of evidence suggests that the biases in online algorithms can influence undecided voters.”

In contrast to Gmail, Outlook and Yahoo Mail were 20% and 14%, respectively, more likely to snag Democratic emails and send them to users’ spam folders.

Gmail has an estimated 1.5 billion users globally, while Outlook has 400 million and Yahoo Mail 225 million.

“Research has long shown that there are biases, explicit or implicit, in the algorithms tech companies employ,” noted Dr. Andy Jackson, director of the Civitas Center for Public Integrity at the John Locke Foundation.

While Yahoo Mail and Outlook were slightly friendlier to right-wing candidates, Gmail “retained the majority of left-wing candidate emails in inbox ([less than] 10.12% marked as spam) while sent the majority of right-wing candidate emails to the spam folder (up to 77.2% marked as spam). We further observed that the percentage of emails marked by Gmail as spam from the right-wing candidates grew steadily as the election date approached while the percentage of emails marked as spam from left-wing candidates remained about the same.”

“As these prominent email services are actively used by a sizable chunk of voting population and as many of the voters today rely on the information they see (or don’t see) online, such biases may have an unignorable impact on the outcomes of an election,” the authors added. “It is imperative for the email services to audit their [spam filtering algorithms] to ensure that any properties of the sender that they consider in determining whether any given email is spam or not are not, unknowingly, putting one side at an advantage compared to the other.”

A spokesperson for Google issued a statement saying, “Political affiliation has absolutely no bearing on mail classifications in Gmail and we’ve debunked this suggestion, which has surfaced periodically from across the political spectrum, for many years … Mail classifications in Gmail automatically adjust to match users’ preference and actions. Gmail users can move messages to spam, or to any other category. Gmail automatically adjusts the classifications of particular emails according to these user accounts.”

“The NCSU researchers found that demographic factors such as age, ethnicity, and sex, had no relationship to the rate at which political emails from the left or right were caught in spam filters,” said Jackson. “Since those demographic factors are correlated with political views, they should have been related to the rate political emails are marked as spam if it is just a matter of email providers responding to user interactions with political emails.”