mx0.firedrake.org has no TXT records.
Question and response
Question
dig mx0.firedrake.org. TXT
Answer
The response has no answer records.
Authority
firedrake.org. 3600 SOA firedrake.org. hostmaster.firedrake.org. 3443716143 21600 10800 604800 43200
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0