I think this distinction between personal and impersonal emails is a good one. The frustration (for me at least) comes in when email isn't relevant, when it's redundant, or when it's unnecessary. My guess is that the problem isn't actually email itself - but it's instead the systems that keep it impersonal.

To paraphrase a blog entry I recently posted (http://blog.klaviyo.com/2012/06/18/making-emails-better-pers...), we need better informed, more intelligent systems and thought to drive what emails are sent/received. For instance:

- There's no reason a company should email me about a feature I already use or a product I already buy. They know this - they just haven't bothered to integrate their systems.

- There's no reason I should have to send 10 emails to schedule a meeting where/when everyone can make it. Our calendars should be able to make this easy and painless.

- There's no reason I should get 4 separate emails from friends containing the same article. Can't I get one message saying four people sent you this?

As Seth Godin said in his Ted talk, something's broken. All of these examples I cite can be solved - and there's a ton more just like them.