48% of emails are opened on mobiles or tablets

"Mobile opens continued their climb toward 50% by gaining another percentage point last month. Emails opened on smartphones and tablets now account for 48% of total opens. Of course, that increase in mobile opens always has to come from somewhere: in September, desktop opens increased to 33%, while webmail opens dipped to 19%.
Mobile opens have gained 10 percentage points since September 2012, while webmail clients have lost that same amount. Interestingly enough, desktop clients have remained relatively flat over the last year. There were some bumps along the road but no overall change from twelve months ago.
iPad and iPhone dominate mobile opens, with a combined total of nearly 80%. Android makes up a respectable 20% of opens, which BlackBerry and Windows Phone combine to represent less than 1%. Growth for each mobile OS has been slow and steady increases across the board."

Source:  Research from Litmus, 8th October 2013