mx1.taugh.com has no CNAME records.
Question and response
Question
dig mx1.taugh.com. NS
Answer
The response has no answer records.
Authority
taugh.com. 3466 SOA sdn.iecc.com. dnsmaster.iecc.com. 2026022722 10800 900 604800 7200
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0