mta2.email.microsoftonline.com has no TXT records.
Question and response
Question
dig mta2.email.microsoftonline.com. TXT
Answer
The response has no answer records.
Authority
email.microsoftonline.com. 3600 SOA ns1.exacttarget.com. hostmaster.exacttarget.com. 2025010702 7200 3600 1209600 3600
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0