mx.noris.de has no TXT records.
Question and response
Question
dig mx.noris.de. TXT
Answer
The response has no answer records.
Authority
noris.de. 600 SOA dns0.noris.net. hostmaster.noris.net.noris.de. 2009224078 86400 86400 2419200 600
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0