Are you hosting everything on "domain.com" (web, ftp, etc.) on your e-smith box? If so, you don't need to do anything. However, if a website for domain.com is hosted somewhere else (like on your ISP's servers), you'll need to update the DNS record with whoever hosts your DNS. Also, if your e-smith box is set up with a different domain, you'll need to add domain.com as a virtual domain to make it accept mail for domain.com.