auth1.met-net.com has no MX records.
Question and response
Question
dig auth1.met-net.com. MX
Answer
The response has no answer records.
Authority
met-net.com. 3600 SOA auth1.dqecom.com. dns.dqecom.com. 568143689 10800 3600 604800 7200
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0