mail.desmaint.com has no TXT records.
Question and response
Question
dig mail.desmaint.com. TXT
Answer
The response has no answer records.
Authority
desmaint.com. 3600 SOA NS19.WORLDNIC.com. namehost.WORLDNIC.com. 125102413 10800 3600 604800 3600
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0