dns06.omniture.com has no MX records.
Question and response
Question
dig dns06.omniture.com. MX
Answer
The response has no answer records.
Authority
omniture.com. 60 SOA ns101.adobe.net. dnsadmin.omniture.com. 168 900 3600 604800 60
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0