auth20.dns.internl.net has no MX records.
Question and response
Question
dig auth20.dns.internl.net. MX
Answer
The response has no answer records.
Authority
dns.internl.net. 3600 SOA auth10.dns.internl.net. hostmaster.internl.net. 2024080701 3600 7200 604800 3600
Additional
. 0 OPT ; payload 1680, xrcode 0, version 0, flags 0