smtp.allegiancetech.com has no CNAME records.
Question and response
Question
dig smtp.allegiancetech.com. NS
Answer
The response has no answer records.
Authority
allegiancetech.com. 600 SOA pdns01.domaincontrol.com. dns.jomax.net. 2026010601 28800 7200 604800 600
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0