Question and response
Question
dig inbound.postmarkapp.com. MX
Answer
inbound.postmarkapp.com. 3600 MX 10 inbound.postmarkapp.com.
Authority
postmarkapp.com. 300 NS ns-1262.awsdns-29.org.
postmarkapp.com. 300 NS ns-1657.awsdns-15.co.uk.
postmarkapp.com. 300 NS ns-229.awsdns-28.com.
postmarkapp.com. 300 NS ns-721.awsdns-26.net.
Additional
inbound.postmarkapp.com. 60 A 52.213.211.243
inbound.postmarkapp.com. 60 A 52.210.157.196
inbound.postmarkapp.com. 60 A 52.51.73.41
. 0 OPT ; payload 4096, xrcode 0, version 0, flags 0