mgt.linequality.totbb.net.net has no MX records.
Question and response
Question
dig mgt.linequality.totbb.net.net. MX
Answer
The response has no answer records.
Authority
net.net. 1800 SOA amir.ns.cloudflare.com. dns.cloudflare.com. 2394600698 10000 2400 604800 1800
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0