mail.allytech.com has no CNAME records.
Question and response
Question
dig mail.allytech.com. NS
Answer
The response has no answer records.
Authority
allytech.com. 3494 SOA ns1.dnscheck.com.ar. root.allytech.com. 2025091105 3600 10800 604800 7200
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0