Question and response
Question
dig _spf.mailgun.org. TXT
Answer
_spf.mailgun.org. 60 TXT "v=spf1 include:_spf1.mailgun.org include:_spf2.mailgun.org ~all"
Authority
mailgun.org. 172800 NS ns-133.awsdns-16.com.
mailgun.org. 172800 NS ns-1482.awsdns-57.org.
mailgun.org. 172800 NS ns-1614.awsdns-09.co.uk.
mailgun.org. 172800 NS ns-586.awsdns-09.net.
Additional
. 0 OPT ; payload 4096, xrcode 0, version 0, flags 0