It's powered by Google Apps and it's free (the magic word)! You will need to have access to your domain management tool and add a few MX entries and a CNAME entry. I also had to put a Google verification code in my site's code for them to verify my ownership of the domain. It was intimidating at first, knowing that one screw up could mess my blog's domain, but after mustering up some courage and reading the instructions thoroughly I emerged victorious.
So now you can email me at jovan [at] bisikleta [d0t] ph. (Sorry, I can't write the email address straight here for fear of getting spammed.)