Question and response
Question
dig mx.paubox.com. TXT
Answer
mx.paubox.com. 60 TXT "v=spf1 ip4:165.140.171.0/24 -all"
Authority
paubox.com. 172800 NS ns-1114.awsdns-11.org.
paubox.com. 172800 NS ns-1972.awsdns-54.co.uk.
paubox.com. 172800 NS ns-222.awsdns-27.com.
paubox.com. 172800 NS ns-790.awsdns-34.net.
Additional
. 0 OPT ; payload 4096, xrcode 0, version 0, flags 0