Why email sucks 

We may despise our inboxes (and 99% of what’s in them), but we’re neurochemically compelled to make sure that there isn’t something potentially important or pleasurable lurking in there this time. And then five minutes from now. And then again. And again. “The internal stimulus is the one that gets you,” Rosen says. “On balance, [email is] maybe 10% pleasure and 90% fear of missing out.”

Source: How email became the most reviled communication experience ever via Engadget