mail.buddyns.com has no CNAME records.
Question and response
Question
dig mail.buddyns.com. NS
Answer
The response has no answer records.
Authority
buddyns.com. 1506 SOA f.ns.buddyns.com. hostmaster.buddyns.com. 1762893570 16384 2048 1048576 2560
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0