selenium.balt.net has no MX records.
Question and response
Question
dig selenium.balt.net. MX
Answer
The response has no answer records.
Authority
balt.net. 60 SOA dns1.balt.net. hostmaster.balt.net. 2012073736 3600 900 604800 60
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0