SBS domain name choice

We are about to set up SBS 2011 at my small company < 10 users. My collaborator wants to name the SBS domain "example.local" . I'm of the opinion we should name the SBS domain "corp.example.com" and setup DNS so the "corp" record is a NS record to the SBS server's private IP.

FYI: "Example.com" isn't the real domain name and while the website is hosted outside our office, email will be stored on the SBS server in our office after passing though a spam filtering smart host hosted elsewhere too.

We use the corp.example.com convention for our small domains. Don't use the .local tld for your domain as it is the tld for Zeroconf/Bonjour, thus any MacOS X clients would not be able connect easily. Also, using a real domain that is registered to you will make life easier for you and your users, especially when they are outside of your office.