Almost everyone I know who uses email extensively for work is overwhelmed by email. People used to talk about achieving 'in-box zero,' that triumphant (yet fleeting) moment when you go through your email inbox and process all email. Processing email means: responding to it, forwarding it, filing it, or deleting it.
In the old days, you could quickly go through your email inbox and delete a lot of stuff and be left with just a few things to respond to or otherwise deal with in some meaningful way. Those days are long gone. I routinely hear people (smart, well-organized, tech-savvy people) say that they've given up on achieving 'in-box zero.' Some people declare 'email bankruptcy,' which means that they delete all the emails in their inbox and then start from scratch. And these are the optimists!
The pessimists have declared that they are giving up on email altogether, often opting to simply use Twitter and the phone. Their strategy is this: communicate en masse to their Twitter followers, and DM ('direct message') those that they want to talk to directly. And anyone else that they want to communicate with (i.e. those who don't use Twitter) they'll talk to by phone. This seems harsh, but it's even harsher when you consider that 'communicating by Twitter' means using 140 characters or less to send messages.
I am not yet a 'pessimist,' and I haven't yet declared email bankruptcy. But I do think that email is 'broken.' Why?
Well, for starters, there are simply too many messages in my inbox to deal with everyday. I could take up at least 30 minutes each day just deleting emails. Filing them would add another hour to the day. The real problem are the emails that I have to respond to. I get at least 30 emails that require some serious response, and probably another 40 or so from people who EXPECT a response even though I can't help them, or can't help them at the time their response comes in.
In short, I am constrained to simply not respond to a number of emails. This makes me very uncomfortable, but I just don't have time to answer. And even if I did, for many of these emails a response would simply generate another email back from the person with a follow up suggestion or question.
So, if you email me and I don't respond it's not because I don't care. It's because I have finite resources and my email situation is totally broken. If you're happy with your email situation then you are truly fortunate. I envy you completely.
For me, email is more burdensome than helpful. And I expect things to get worse.