sync.datamine.com has no MX records.
Question and response
Question
dig sync.datamine.com. MX
Answer
The response has no answer records.
Authority
datamine.com. 3600 SOA ns.freeparking.co.nz. admin.syrahost.com. 1770762447 3600 7200 3600000 3600
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0