ns3.vodafone.com has no MX records.
Question and response
Question
dig ns3.vodafone.com. MX
Answer
The response has no answer records.
Authority
vodafone.com. 900 SOA ns1.vodafone.com. hostmaster.vodafone.com. 2008109910 28800 7200 604800 900
Additional
. 0 OPT ; payload 1220, xrcode 0, version 0, flags 0