sth.nz has no MX records.
Question and response
Question
dig sth.nz. MX
Answer
The response has no answer records.
Authority
sth.nz. 3600 SOA ns1.sth.nz. hostmaster.sitehost.co.nz. 1 10800 3600 604600 3600
Additional
. 0 OPT ; payload 1680, xrcode 0, version 0, flags 0