As long as you own the domain, it doesn't matter if you have a site up or not -- just sign up for Google Apps and use Gmail. You don't need to have a website, you just need to be able to control the DNS setting (which you should be able to do with any registrar.) I use Google for email on most of the domains I own whether I have a site up on not.
I find the free level of Google Aps works fine for all of the email accounts that I have on various domains, but if you need a lot of mail storage (25GB) you can pay $50/year for the business level.
I prefer using Google over GoDaddy's email service or even hosting email on my own server. Google does a much better job of spam filtering.
http://www.google.com/apps/intl/en/group/index.html