smtp80.mediacombb.net has no MX records.
Question and response
Question
dig smtp80.mediacombb.net. MX
Answer
The response has no answer records.
Authority
mediacombb.net. 300 SOA pdns104.ultradns.com. internetsupport.mediacomcc.com. 2021063189 10800 3600 604800 300
Additional
. 0 OPT ; payload 4096, xrcode 0, version 0, flags 0