A concept that I like from the 4-Hour Work Week book is that we are not naturally multitaskers but we convince ourselves that we are.
Try and take one task during your day and do it without getting distracted by anything else, I bet you can't. The distraction can include other people, outlook, or meetings try to eliminate it!
As a developer if I am working on a piece of code is there really a reason for me to have Outlook open? It is natural to say yes, but
The first thing that I tried to implement in my life from the book was setting times that I could check email and sticking to them. My times were 11:30am and 4:30pm. How did it go? It went really well and I quickly found out that email wasn't as important as I previously thought it was. I also found out how hard it was to change the habit of letting things like email take a backseat to the task I wanted to accomplish. My best advice is to disable the popup that comes up when you get email and to disable any sound notification.