mx.1-800-the-nerd.com has no CNAME records.
Question and response
Question
dig mx.1-800-the-nerd.com. NS
Answer
The response has no answer records.
Authority
1-800-the-nerd.com. 916 SOA dns.1-800-the-nerd.com. hostmaster.1-800-the-nerd.com. 1779537838 43200 3600 604800 3600
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0