Because so many of us don't do it - or do it so inefficiently that we might as well have three times the number emails we actually have.
When I first started teaching distance education courses, I installed Microsoft Office and set all my email up on Entourage (similar to Outlook Express) and THEN I wrote a "rule" that would automatically check email every five minutes. As a result, I got email... every five minutes. It was great, except for one thing: it gave me a false sense of control regarding my email inbox. I'll give you an example: I once got an email that went something like this:
From: Angry McStudent@learnstuff.net
Re: my paper
Yo, I don't get why you always gives me bad grades on my papers and I think you are wrong. You should read my papers and gives me grades, highest. I have a problem with you.
Now, I get emails like this more than I'd like. (I would prefer never, thanks). But when I got this one, I did what I normally do when I don't know quite what to think: I waited. Had I written back right away, I might have written something like this:
To: Angry McStudent@learnstuff.net
Re: my paper
Your papers are, as I clearly stated in my comments, not passing because you did not follow the directions. Also, your grammar is so poor that I often wonder whether you are writing in alien-script and using a transliteration button. I can't pass you unless you actually learn something. That's why you are in school. And by the way, your problem is with you and your failing papers. Once I give you the F you so rightly deserve, I'll forget about you entirely. But your transcript? That's forever, so I suggest you get to work.
So as might be able to tell, I was a little miffed at being addressed as "yo" and I didn't really appreciate being called "wrong." Also, the student's poor command of verbs was irresistibly funny, considering he was complaining of poor paper grades. In short, I was too conflicted to compose a response right that second. So I went for a run and flossed my teeth and perhaps I even baked a cake.*
Then I returned to the computer and composed an even-tempered and professional reply:
To: Angry McStudent
Re: my paper
I am sorry you are having trouble understanding my paper comments and your grades. Why don't we schedule a phone conference or an IM conversation and go over each paper? Please let me know what time would be convenient for you. I will be on instant messenger between 2pm and 4pm today. You can also reach me by phone at XXX-XXX-XXXX.
Now you might thinking: ah, you are advocating letting your emotions cool rather than writing a sassy reply. If you are thinking that, you are WRONG.
Here's the thing: teachers are passionate about what they do and they are passionate about their fields of expertise. As a result, most of us personalize our jobs far too much. What I should have done was taken perhaps two deep breaths before writing the inevitable (and far more helpful) reply. I knew exactly what the "real" reply would be; I did not need to bake a cake to figure it out. And by waiting, I caused myself three very real problems:
1) I put myself at risk of forgetting to reply at all - and I am sure I do not need to tell you why that would have been bad, indeed.
2) I let the student, who was probably very itchy and uncomfortable about having written the email, stew in his own regret for hours. That was not very nice of me.
3) Worst of all, I caused myself to have to handle the same piece of email TWICE. That's right: I ended up spending two times the the amount of time answering that email. And the end result was the same.
Summary: open it once, answer it immediately. If you are having feelings, shake it off. It's your job.
Have a good weekend, and thank you for reading.
*I don't remember, but I am sure this is close.