A great article by MediaPost discussing the latest ComScore numbers regarding email usage:
http://www.mediapost.com/publications/?fa=Articles.showArticle&art_aid=143363&nid=122890
Daily mobile email usage is up 40% year over year for November 2010. I’m not surprised about this stat, due to the proliferation of mobile devices that are highly email friendly such as the BlackBerry, iPhone, Droids and iPad.