I'm a latecomer to it, in part because I have a very hit-or-miss interest in new technologies. (I still don't own a cell phone, for example, though I check my e-mail 4,000 times a day.)
Now. There are 24 hours in a day. 1 440 minutes. 86 400 seconds. Thus, checking e-mail 4 000 times in a day would require you to check your inbox every 21.6 seconds. Day and night.
Either the author is innumerate or hyperactive.