Hillary Clinton and Bernie Sanders hold big advantages over Donald Trump in email list size, but the presumptive GOP nominee tops both Democrats in email open rate, according to recent data from Return Path.

The report was based on 2016 data from Return Path's Consumer Network, comprising information from more than 2.5 million individual inboxes.

The researcher examined how each candidate’s email metrics compare with industry (Government, Nonprofit, and Education) benchmarks.

Both Hillary Clinton and Bernie Sanders have more email subscribers than Donald Trump, the analysis of Return Path data found.

Donald Trump has the highest average email open rate of the three candidates.

Bernie Sanders has the lowest "deleted without opening" rate, meaning that his subscribers are the least likely to send campaign messages directly to the trash.

About the research: The report was based on 2016 data from Return Path's Consumer Network, comprising information from more than 2.5 million individual inboxes.