mail.windmillcache.com has no TXT records.
Question and response
Question
dig mail.windmillcache.com. TXT
Answer
The response has no answer records.
Authority
windmillcache.com. 3600 SOA dns.windmillcache.com. hostmaster.windmillcache.com. 1584239809 43200 3600 604800 3600
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0