mail01.ipfire.org has no TXT records.
Question and response
Question
dig mail01.ipfire.org. TXT
Answer
The response has no answer records.
Authority
ipfire.org. 300 SOA master.lwldns.net. hostmaster.ipfire.org. 2026033548 10800 1800 1209600 300
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0