smtprelay.aureon.com has no TXT records.
Question and response
Question
dig smtprelay.aureon.com. TXT
Answer
The response has no answer records.
Authority
aureon.com. 3600 SOA ns1d.aureon.com. hostmaster.netins.net. 2017103604 1800 3000 604800 86400
Additional
. 0 OPT ; payload 1220, xrcode 0, version 0, flags 0