If email is taking over your day, chances are your productivity is dropping. Try checking the mailbox less and stay on task longer. I know I am guilty of this, and my days do not seem as productive. Between phone calls, emails and other miscellaneous fires its hard to get it all covered in a day.
Thinking about changing my mail to be checked on the hour rather than every five minutes. Rather than have the typical sound notification that lets me know there was a piece of spam that arrived, I am going to try this out and see how much more I can stay on task. I don't know about checking it every Friday though. I would like to keep the messages flowing - but with less distractions to my schedule.