ns3.ac.lk has no MX records.
Question and response
Question
dig ns3.ac.lk. MX
Answer
The response has no answer records.
Authority
ac.lk. 5677 SOA ns1.ac.lk. noc.learn.ac.lk. 2026020902 7200 600 1209600 10800
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0