RALEIGH, N.C. (WNCN) — Does your email’s spam folder lean to the political right or left?

Some researchers at North Carolina State University think it might.

A study published recently by four computer science researchers at the school looked closer at three popular email services and found Gmail was more likely to send emails from Republican campaigns into a user’s spam folder while Microsoft Outlook and Yahoo were more likely to do the same thing to Democratic candidates.

The study caught the attention of Republicans who, according to news reports, cited its findings in a complaint filed this week with the Federal Election Commission.

It looked at those three services from July 1, 2020, through Nov. 30 of that year. 

They created 102 email accounts — 34 on each — and subscribed to two presidential, 78 U.S. Senate and 156 U.S. House candidates from across the country and received more than 318,000 emails.

“We observed that the (spam-filtering algorithms) of the email services indeed exhibit political biases,” the researchers wrote.

During that time, the researchers say Gmail marked as spam 68 percent of emails from Republicans and 8 percent of those from Democrats.

They concluded that Outlook is “unfriendly to all campaign emails, more unfriendly to the left than to the right” and marked a higher percentage of emails from the left (nearly 96 percent) as spam compared to 75 percent of those from the right.

And they say Yahoo marked 14 percent more emails from Democrats as spam than Republicans.

The researchers — Hassan Iqbal, Usman Mahmood Khan, Hassan Ali Khan and Muhammad Shahzad — did not respond to repeated requests for interviews over the past week from CBS17.com.

They conclude that the popular email services should take a closer look at how their spam filters work.

“While we have no reason to believe that there were deliberate attempts from these email services to create these biases to influence the voters, the fact remains there that their (spam-filtering algorithms) have learnt to mark more emails from one political affiliation as spam compared to the other,” the researchers concluded.

“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.”