I've been using a variation on the DMZ idea for a while. I have a seperate email folder called @stack. Every morning I come in and move my inbox mail to @stack and work through it using GTD principles. I ignore any new mail coming in to the inbox. I then repeat the process after lunch.
It still takes me a long time to get through my mail but helps to stop me becoming "email driven" where I just end up spending the day responding to emails as they plop into my inbox thus being continually diverted.
The drawback is occasionally my boss asks me if I've seen such-and-such email (which only arrived 2 minutes before)... and, of course, I haven't because I don't check my email every bloody minute! Will have to explain GTD to him at some point...
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Cheers
Mark