ns2.wix.com has no MX records.
Question and response
Question
dig ns2.wix.com. MX
Answer
The response has no answer records.
Authority
wix.com. 3600 SOA dns1.p03.nsone.net. hostmaster.nsone.net. 1749720463 3600 600 604800 3600
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0