I was hosting my own email server for about a year. I enjoyed the fact that I had full and complete control over the entire mail server. I enjoyed being able to fine tune everything to fit my needs exactly. I was doing this for about 1.5 years.
Unfortunately, there were a few things I couldn't control that really killed the fun of running my own email server. First of all, dealing with the people complaining that it's not how they want it weighed on me. Aside from that there were also power outages, hardware failures, software hangs (from power dips), firewall/router deaths, modem spasms (now very frequent), etc. Not only that, but I only had 1mbit upload available and 1.5mib max available at about $100/mo more.
What it came down to is that running a mail server just isn't for me given my limitations. I needed an alternative and I found one. There is this thing called Google Apps (google.com/a) that is capable of hosting your domain email for you.
I decided to give it a shot. It's not a quick or idiot proof process, but it was worth the effort.