Question and response
Question
dig _spf1.mailgun.org. TXT
Answer
_spf1.mailgun.org. 60 TXT "v=spf1 ip4:209.61.151.0/24 ip4:166.78.68.0/22 ip4:198.61.254.0/23 ip4:192.237.158.0/23 ip4:23.253.182.0/23 ip4:104.130.96.0/28 ip4:146.20.113.0/24 ip4:146.20.191.0/24 ip4:159.135.224.0/20 ip4:69.72.32.0/20 ~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