biz.spectrum.com has no MX records.
Question and response
Question
dig biz.spectrum.com. MX
Answer
The response has no answer records.
Authority
biz.spectrum.com. 14400 SOA auth1.charter.com. hostmaster.charter.com. 2019215137 7200 3600 604800 14400
Additional
. 0 OPT ; payload 4096, xrcode 0, version 0, flags 0