CNAME for top of domain?
Is it possible to set a CNAME record at the top of a domain? (i.e. @ CNAME www, @ CNAME foobar.com., etc.)
My ISP says that it's only possible to use CNAME's for subdomains but I've read somewhere else that is should be possible even if not recommended.
Not possible - this would conflict with the SOA- and NS-records at the domain root.
From RFC1912 section 2.4: "A CNAME record is not allowed to coexist with any other data."
You can setup your domain to be a CNAME to another domain, but then everything will go to that other domain -- including mail and the SOA "start-of-authority" record itself. However, you can still have separate subdomains, like "private.domain.com" use another mail and web server.
I use cloudflare to setup CNAME for root domain and it works fine.. without breaking the mail records