Goin' Mobile - E-mail

A report from email specialist Return Path suggests that people are increasingly using mobile devices to access and open emails.
  Mobile's share of email opens has tripled in the last two years, while the use of desktop email clients has declined slightly.  Much of that growth seems to have come from a shift from the use of Webmail portals, and may be less of a shift in terms of when and where people access email, than a change in the devices used.  That is, Webmail portals offered mobile (non-fixed) access on desktops and laptops.  Smartphones and tablets now enable mobile access 24/7 through personal devices, both extending mobile access capacity with smaller and lighter personal devices.  Users away from their primary desktops may be shifting their preferred access point from Webmail to mobile devices.
  Still, email access habits vary across regions. In the U.S., 38% of all emails are opened on mobile devices, compared to 31% opened through a desktop email client, and 31% opened through a webmail portal.  In Brazil, France, Germany, and Spain, mobile's share of email opens falls below 20%; with Webmail portals being the dominant email access point.  The U.K. is seeing mobile usage rising to about one-quarter of email opens.
  The study also asked users about how frequently they accessed emails on various devices.  Looked at that way, more people report using desktop email clients on a daily basis than report using mobile devices to access emails daily.  While use patterns vary globally, more than 70% of users in indicate daily email access via desktop email clients, and more than 50% of mobile users indicate using their devices to access email daily.
   Apple devices dominate mobile email use, at least for now.  The study found that 59% of all mobile email opens occur on iPhones, while iPads account for 26%.  Android mobile devices currently account for 14% (with an occasional Windows user accounting for 0.3%).  The report indicates that this number may be somewhat skewed, as Apple automatically opens images when grabbing emails from host servers.
  There's some interesting results on use of emails from retailers in the infographic.

Sources - Consumers Favor Mobile for Email,  Online Media Daily
ReturnPath press release and infographic