Emails sent by utilities companies had the highest read rate in 2015 at 47 percent, according to a new report from Return Path. The research revealed that distribution/manufacturing emails came in second at 31 percent and business/marketing and social/dating companies had the lowest read rate at 9 percent. The Hidden Metrics of Email Deliverability examined more than 3.5 billion commercial emails and found that promotional emails delivered to the spam folder ranged from just 2-28 percent depending on the industry.