ns2.GOOGLE.COM has no MX records.
Question and response
Question
dig ns2.GOOGLE.COM. MX
Answer
The response has no answer records.
Authority
GOOGLE.COM. 60 SOA ns1.GOOGLE.COM. dns-admin.GOOGLE.COM. 873285235 900 900 1800 60
Additional
. 0 OPT ; payload 512, xrcode 0, version 0, flags 0