pbxmailer.techvalleycom.com has no MX records.
Question and response
Question
dig pbxmailer.techvalleycom.com. MX
Answer
The response has no answer records.
Authority
techvalleycom.com. 3600 SOA cns1.firstlight.net. hostmaster.mhonline.net. 2007020603 10800 3600 604800 3600
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0