Consider blocking your own calendar for meetings with yourself. I know many people & teams that do this just to create some protected calendar time for processing email at the beginning and end of day. A good guideline for how much time you need is about 30 seconds to process each piece of input you get (paper or digital). For most people that comes out to about an hour to hour and a half per day for their own processing time.
Kelly Forrister at DavidCo has some ideas for you to try that all include taking back some time at work so you can have some breathing space.
Being selfish with your time – [DavidCo]