gov.sg has no MX records.
Question and response
Question
dig gov.sg. MX
Answer
The response has no answer records.
Authority
gov.sg. 3600 SOA ds.sgnic.sg. dna.sgnic.sg. 2603070130 2700 1800 2419200 3600
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0