Emailaholics??

I’m condensing the article at www.technologyreview.com here:

A team at Yahoo Research work out how to classify individuals by their email habits --   ‘day labourers’ and ‘emailaholics’.  These terms represent “two distinct types of emailer.”  Day Labourers tend to “send emails throught the normal working day between 0900 and 1800 but not at other times.” Emailaholics send emails “throughout the waking hours from 0900 to 0100.”