mail4.link11.com has no TXT records.
Question and response
Question
dig mail4.link11.com. TXT
Answer
The response has no answer records.
Authority
link11.com. 900 SOA ns1.link11.de. hostmaster.link11.de. 1772492620 16384 2048 1048576 900
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0