mail2.onexs.com has no MX records.
Question and response
Question
dig mail2.onexs.com. MX
Answer
The response has no answer records.
Authority
onexs.com. 3600 SOA ns1.as60402.net. hostmaster.as60402.net. 2025030303 10800 3600 604800 3600
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0