mullan.m1net.com.sg has no MX records.
Question and response
Question
dig mullan.m1net.com.sg. MX
Answer
The response has no answer records.
Authority
m1net.com.sg. 900 SOA pridns.m1net.com.sg. hostmaster.m1net.com.sg. 2015042337 10800 3600 2419200 900
Additional
. 0 OPT ; payload 1220, xrcode 0, version 0, flags 0