Question and response
Question
dig cluster9.us.messagelabs.com. MX
Answer
cluster9.us.messagelabs.com. 60 MX 10 mail905.messagelabs.com.
cluster9.us.messagelabs.com. 60 MX 10 mail912.messagelabs.com.
cluster9.us.messagelabs.com. 60 MX 10 mail924.messagelabs.com.
cluster9.us.messagelabs.com. 60 MX 10 mail932.messagelabs.com.
cluster9.us.messagelabs.com. 60 MX 10 mail946.messagelabs.com.
cluster9.us.messagelabs.com. 60 MX 10 mail952.messagelabs.com.
Authority
messagelabs.com. 180 NS ns-1296.awsdns-34.org.
messagelabs.com. 180 NS ns-1714.awsdns-22.co.uk.
messagelabs.com. 180 NS ns-453.awsdns-56.com.
messagelabs.com. 180 NS ns-520.awsdns-01.net.
Additional
mail905.messagelabs.com. 900 A 67.219.246.219
mail912.messagelabs.com. 900 A 67.219.246.213
mail924.messagelabs.com. 900 A 67.219.247.111
mail932.messagelabs.com. 900 A 67.219.247.207
mail946.messagelabs.com. 900 A 67.219.250.220
mail952.messagelabs.com. 900 A 67.219.250.219
. 0 OPT ; payload 4096, xrcode 0, version 0, flags 0