c-50-169-166-210.unallocated.comcastbusiness.net has no MX records.
Question and response
Question
dig c-50-169-166-210.unallocated.comcastbusiness.net. MX
Answer
The response has no answer records.
Authority
comcastbusiness.net. 900 SOA ns.comcastbusiness.net. domregtech.comcastonline.com. 2008113806 7200 300 604800 900
Additional
. 0 OPT ; payload 4096, xrcode 0, version 0, flags 0