44.76% of a sampling of 3 million retail marketing e-mails sent between the Tuesday before Thanksgiving and midnight on Cyber Monday (November 20-26, 2012) were opened on a mobile device, mobile marketing firm Knotice finds. That’s up from 30.50% for the same period in 2011.

28.22% of these e-mails were opened on a smartphone: 23.93% on an iPhone, 4.15% an Android smartphone, 0.08% a Windows Phone, 0.02% a BlackBerry, 0.01% a Palm, and 0.03% other smartphones, Knotice finds.

16.54% of these e-mails were opened on a tablet: 15.81% on an iPad, 0.64% an Android tablet, and 0.09% other tablets, the firm says.

Looking at the data from the Apple Inc. versus Google Inc. Android perspective, Apple overshadows Android. Examining smartphones, 23.93% of e-mails were opened on an iPhone while only 4.15% were opened on an Android phone. This is counter to market share, as 52.5% of smartphones in use are Android devices and 34.3% are iPhones, according to web and mobile measurement firm comScore Inc.

The disparity is caused at least in part by the way e-mail opens are recorded, explains Patti Renner, director of marketing at Knotice.

“The way most platforms record an e-mail open via mobile is based on image load—‘show images’ or ‘download images.’ Images show as a default on iPhones, but it often is not a standard setting on Android devices,” Renner says. “As a result, Android devices seem to underperform. Consumers can go into their settings and make the change if ‘images off’ is set as a default, but few do.”

The bottom line is retailers may want to ensure their e-mails are optimized for viewing on smartphones, and that their e-mails’ pre-header text, tiny copy that appears at the very top of an e-mail, includes a message for how to view the e-mail in a web browser if the consumer cannot see images in the message, mobile experts say.