mx1.oncallcentre.com has no TXT records.
Question and response
Question
dig mx1.oncallcentre.com. TXT
Answer
The response has no answer records.
Authority
oncallcentre.com. 3600 SOA ns65.domaincontrol.com. dns.jomax.net. 2025082601 28800 7200 604800 3600
Additional
. 0 OPT ; payload 1280, xrcode 0, version 0, flags 0