I've never understood why busy people don't use staff to "pre-clean" the inbox. Especially if you get dozens of emails a day. After a vacation (heck, every day), I spend a lot of time deleting spam, daily reports, and threads I'm cc'd in (but get resolved by others).
Tom Osborne (the legendary Nebraska football coach and now athletic director for those who don't watch college football) does this. In fact, he sends and receives his email through an assistant, at least when dealing with the public. Still personal, but I imagine it helps him stay sane.