Singletasking by Caterina Fake (photo)
flickr.com
flickr.com
Email is not a serious thing this days. It is too simple to send one, and people keep writing emails about things not important, or that are trivial to figure without any help, containing a lot more words than needed to express an otherwise simple message and so on.
Do you really want to pass half of your life reading/writing emails about things that don't interest you? I don't want. This is one of the things that may affect your work performance in a critical way.
Trying to stick at inbox zero after that has been a definite improvement, but it does make for painful periods when I'm away for a day and come back to a ton of unread rubbish I'd normally just archive as soon as it came in. Theoretically select-all-unread-archive is easier than interrupting focus, archive, resuming focus, but the mental burden of 200+ unread messages is not to be underestimated.
(...says someone who used to work in a place that would have gotten me fired if I had worked like this.)
What's the cause of allowing yourself to be distracted so much? Not focusing enough on your core work.
Once you focus on the most important thing, you'll be too busy to be distracted.
If you're not focusing on the most important thing, your problems are too big to be solved with a white board gimmick.