163.206.223.3.in-addr.arpa.
Question and response
Question
dig awsmail.easyvista.net. PTR
Answer
awsmail.easyvista.net. 86400 PTR 163.206.223.3.in-addr.arpa.
Authority
easyvista.net. 172800 NS ns-1148.awsdns-15.org.
easyvista.net. 172800 NS ns-2020.awsdns-60.co.uk.
easyvista.net. 172800 NS ns-4.awsdns-00.com.
easyvista.net. 172800 NS ns-913.awsdns-50.net.
Additional
. 0 OPT ; payload 4096, xrcode 0, version 0, flags 0