It can work out of the box. IF no account has been configured, select MS Exchange, enter you e-mail addy domain name\username and password.
The default description witll be the e-mail address but may be changed to anything (ie my e-mail), hit next.
You should then see the screen asking for the server name enter mobile.(your domain.com) and hit next.
You might get an error "Unable to verify certificate" just hit accept.
After this you should receive confirmation that the Exchange account is verified and be immediately presented with the sync with Exchange screen, click save. It will take some time for the mailbox and folders to sync.
On the settings page, under mail, contacts, calendars you can configure options for the e-mail account IE days of email to sync, how many messages to show, font size, siggie. etc. YOu will also find options for calendar and contacts as well.