mobilemail.cspire.com has no CNAME records.
Question and response
Question
dig mobilemail.cspire.com. NS
Answer
The response has no answer records.
Authority
cspire.com. 1800 SOA alexia.ns.cloudflare.com. dns.cloudflare.com. 2397618451 10000 2400 604800 1800
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0