_spf.rackanddata.com has no CNAME records.
Question and response
Question
dig _spf.rackanddata.com. NS
Answer
The response has no answer records.
Authority
rackanddata.com. 927 SOA authns1.rackanddata.com. domainadmin.rackanddata.com. 1375326455 10800 3600 604800 38400
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0