mx.matzohballs.com has no CNAME records.
Question and response
Question
dig mx.matzohballs.com. NS
Answer
The response has no answer records.
Authority
matzohballs.com. 3552 SOA dns.matzohballs.com. hostmaster.matzohballs.com. 1927166622 43200 3600 604800 3600
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0