mx-alt3.ennit.net has no MX records.
Question and response
Question
dig mx-alt3.ennit.net. MX
Answer
The response has no answer records.
Authority
ennit.net. 300 SOA ns1.ennit.net. hostmaster.support.ennit.de. 2026022001 14400 7200 3600000 86400
Additional
. 0 OPT ; payload 1400, xrcode 0, version 0, flags 0