nic53.net has no MX records.
Question and response
Question
dig nic53.net. MX
Answer
The response has no answer records.
Authority
nic53.net. 3600 SOA ns1.nic53.net. technik.internexum.de. 1573499518 14400 1800 1209600 3600
Additional
. 0 OPT ; payload 1400, xrcode 0, version 0, flags 0