Before we have all those fancy new email technology, can we simply tell the companies get rid of the aging MS Outlook and exchange server, move to a cooperate gmail server. Having powerful filter, tags and search function can help us organize our email a long way.
My solution to the problem of email overload is have two computers at work. Run your email client in your windows machine and work on your UNIX machine. When you really concentrate coding in UNIX, you will simply ignore the emails coming to your Laptop. If the email is urgent enough, you will get a phone call or someone will show up at your queue.