RESTON, VA: US email habits are undergoing a dramatic shift, with more and more people checking their messages on their phones.

Visitors to email websites fell 6% between November 2009 and November 2010, according to comScore.

But use of mobile email climbed 36% over the same period and now covers 78% of the nation's smartphone population, in what the research firm is calling an "email evolution".

Around 153 million Americans visited email sites such as and during November 2010, spending a collective 43,474 minutes on the site and viewing 38,204 pages.

These totals are 6%, 9% and 15% lower than their equivalents for November 2009.

The drop-off in usage is sharpest among younger demographics, though the number of over-55s actually increased from the previous year.

In all, 70m Americans used their mobiles to access email during the month.

This not only represents a 36% increase in users, but a 40% increase in daily users - suggesting that accessing the services has become routine.

Mark Donovan, comScore senior vice president of mobile, suggested the trend towards mobile is part of the general fragmentation of media use observed over recent years.

"From PCs to mobile devices, whether its email, social media, IM or texting, consumers have many ways to communicate and can do so at any time and in any place," he said.

"The decline in web-based email is a byproduct of these shifting dynamics and the increasing availability of on-demand communication options."

Data sourced from comScore; additional content by Warc staff