spf.zamailgate.com has no CNAME records.
Question and response
Question
dig spf.zamailgate.com. NS
Answer
The response has no answer records.
Authority
zamailgate.com. 190 SOA ns-1524.awsdns-62.org. zadns.firewall.gmail.com. 1 7200 900 1209600 86400
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0