b4.volfix.net has no MX records.
Question and response
Question
dig b4.volfix.net. MX
Answer
The response has no answer records.
Authority
volfix.net. 1800 SOA dane.ns.cloudflare.com. dns.cloudflare.com. 2396895087 10000 2400 604800 1800
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0