Yes, you can. We’ve taken all the hassle out of setting this up too.
In our Domain Manager where you manage DNS settings for you domain, we have a couple of configuration aids to make your life a little bit easier. One of these allows you to set your domain up to work with Google Apps in a few clicks. This’ll allow you to use convenient sub-domains such as mail.[yourdomain.com], docs.[yourdomain.com], etc. to easily get to your Google Apps. To get started with this, in Domain Manager, hit the Google Apps icon as shown on the left-hand side in the image above.
On the next screen, simply select the subdomains you would like to configure to work with Google Apps and hit the button to set it all up for you. Note, these changes might take a few hours to kick in.