Question and response
Question
dig sparkpostmail.com. MX
Answer
sparkpostmail.com. 300 MX 5 smtp.sparkpostmail.com.
Authority
sparkpostmail.com. 172800 NS ns-1361.awsdns-42.org.
sparkpostmail.com. 172800 NS ns-1855.awsdns-39.co.uk.
sparkpostmail.com. 172800 NS ns-304.awsdns-38.com.
sparkpostmail.com. 172800 NS ns-775.awsdns-32.net.
Additional
smtp.sparkpostmail.com. 60 A 18.236.40.4
smtp.sparkpostmail.com. 60 A 54.203.214.124
smtp.sparkpostmail.com. 60 A 52.24.228.93
. 0 OPT ; payload 4096, xrcode 0, version 0, flags 0