smtp.directcom.com has no CNAME records.
Question and response
Question
dig smtp.directcom.com. NS
Answer
The response has no answer records.
Authority
directcom.com. 1531 SOA marge.ns.cloudflare.com. dns.cloudflare.com. 2395667111 10000 2400 604800 1800
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0