mail92.outbound.mtb-1.com has no MX records.
Question and response
Question
dig mail92.outbound.mtb-1.com. MX
Answer
The response has no answer records.
Authority
mtb-1.com. 3600 SOA pdns01.domaincontrol.com. dns.jomax.net. 2019072200 28800 7200 604800 3600
Additional
. 0 OPT ; payload 1280, xrcode 0, version 0, flags 0