A reader shares a research report: The world of email marketing has changed pretty significantly over the past five years. Where desktop clients like Outlook were once a more important delivery medium, readers of email are now in the thrall of mobile clients and webmail services like Gmail. In fact, new research from Return Path found that more than half of emails worldwide (55%) are opened in a mobile environment in 2017, significantly more than either webmail (28%) or desktop (16%). Mobile has emerged as the dominant email environment since Return Path last conducted its survey in 2012, when only 29% of emails were opened on a mobile device, and webmail clients were the most popular method of accessing such electronic missives. Return Path also found that Apple's iOS was dominant among mobile email users worldwide, with 79% of mobile emails opened on either an iPhone or iPad this year. While only 20% of emails were opened on a device running Android, that was actually an increase of 6 percentage points from 2012's figure.