mail1.netnames.com has no TXT records.
Question and response
Question
dig mail1.netnames.com. TXT
Answer
The response has no answer records.
Authority
netnames.com. 21600 SOA udns1.cscdns.net. hostmaster.cscdns.net. 2017101358 3600 1800 3600000 21600
Additional
. 0 OPT ; payload 4096, xrcode 0, version 0, flags 0