Work aside, how does the average user have 2.5 hours worth of personal emails to attend to per day?
Even if they won't admit it, I'm sure some people open their inbox and stare blankly as a subconscious way of taking a break.
Plus, some people do generally have answering email as their job.
Lets face it we tend to do those things through Web interfaces on desktop/laptops or in messaging style apps on phones that tend to look quite similar in layout.
And we need to be clear about the time frame as other posters have mentioned (per day or per week)
On the work based figures, I suspect that people include the time spent on a task generated by the email as 'doing email'. My colleagues certainly would, and a lot of the work related email we get is providing information directly into a rich format email.
This probably accounts for a large chunk of the reported hours, as well.
I lost my window seat a while ago and that's one thing I really miss. I used to look out the window and think. Now I often obsessively check Email or Hacker News.
If I wanted to, I could easily fill my entire day with reading and responding to E-mail. Part of good E-mail hygiene is being able to quickly sort by importance and urgency, responding to the urgent stuff now, getting to the important stuff later, and shit-canning the rest.
I also send (initiate) a lot of E-mail, so it’s not just reading. Again, I could probably spend all day writing and sending E-mails but it’s not scalable and would leave me no time to do my other work. So I have to use discipline and pick and choose and only send the most urgent messages.
It’s easy to lose your whole day to E-mail if you’re not careful.