emailmx.com has no TXT records.
Question and response
Question
dig emailmx.com. TXT
Answer
The response has no answer records.
Authority
emailmx.com. 1200 SOA ns1.mdnsservice.com. hostmaster.mdnsservice.com. 0 10800 3600 2592000 86400
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0