Email augments my life but does not control it. That's where the distinction is. Much as writing letters is a tool, so is email. If it went away, the world would not end for me and I intend to keep it that way.
Availability? If mail doesn't get delivered immediately, thanks to the joys of SMTP, it will come later (when my ADSL line is back up). If it's urgent, someone can put mouth to phone rather than finger to keyboard.
Updating packages? Cron does this for me once a week. Maintenance? There is none. Everything is done properly once and automated.
I access everything via SSH if I have to which is rarely. I avoid email on the move where possible as there are more important things to do like looking in front of you and not worrying about stuff.
I make sure I don't need past emails. Not everything everyone has written is golden. In fact most of it is useless and just noise.
For reference's sake, I trialled Google Apps on a domain for 2 months as a possible replacement for my setup. It was a pain in the butt. There is actually no support worth anything if it does go wrong which it did terribly (gmail stopped working entirely with a server error). The entire domain approval process is problematic and time consuming and their contracts are disagreeable. Plus it didn't deliver any additional value.
Ultimately, if you look at it, there is actually more work to setting up a system to backup contacts and calendars and watching that than there is to operate my setup entirely.
I assume you are backing up your google apps accounts?