Google (in their plan to take over the world) has one of the best email systems you can find: Gmail. Their spam filter cannot be beat, and the integration with all of their other apps (online documents, calendars, etc.) is amazing. Plus - you can store MASSIVE amounts of data on there. My accounts have around 7GB of storage - and it keeps growing! I know people who use it as a backup hard drive - just email important docs to themselves. Lots of folks have an @gmail.com email address to take advantage of the above features, but did you know that you can funnel all of your business email through Gmail - for free? That's exactly what we do here at FPM and what I recommend to all of our clients.
To get started, just go to the Google Apps Standard Edition page and sign up. They have pretty good instructions, but you might need to get with your IT folks to get it going right.
So - happy emailing, and good luck!