resolver1.trust.zone has no MX records.
Question and response
Question
dig resolver1.trust.zone. MX
Answer
The response has no answer records.
Authority
trust.zone. 1800 SOA janet.ns.cloudflare.com. dns.cloudflare.com. 2397263615 10000 2400 604800 1800
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0