free has no MX records.
Question and response
Question
dig free. MX
Answer
The response has no answer records.
Authority
free. 60 SOA dns1.nic.free. hostmaster.nominet.org.uk. 1771826943 900 300 2419200 60
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0