mx.propersupport.com has no TXT records.
Question and response
Question
dig mx.propersupport.com. TXT
Answer
The response has no answer records.
Authority
propersupport.com. 1800 SOA propersupport.com. root.propersupport.com. 1676297270 28800 7200 604800 86400
Additional
. 0 OPT ; payload 600, xrcode 0, version 0, flags 0