ns3.superonline.net has no MX records.
Question and response
Question
dig ns3.superonline.net. MX
Answer
The response has no answer records.
Authority
superonline.net. 300 SOA ns4.superonline.net. system.superonline.net. 2026020401 3600 3600 604800 3600
Additional
. 0 OPT ; payload 4096, xrcode 0, version 0, flags 0