mc.tmt.de has no MX records.
Question and response
Question
dig mc.tmt.de. MX
Answer
The response has no answer records.
Authority
tmt.de. 600 SOA ns0.tmt.de. hostmaster.ns0.tmt.de. 2025101052 28800 7200 604800 600
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0