mx.directi.com has no CNAME records.
Question and response
Question
dig mx.directi.com. NS
Answer
The response has no answer records.
Authority
directi.com. 119 SOA usc4.akam.net. syseng-senior.directi.com. 2018110849 43200 3600 1209600 180
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0