mail.clearspaninc.com has no MX records.
Question and response
Question
dig mail.clearspaninc.com. MX
Answer
The response has no answer records.
Authority
clearspaninc.com. 3600 SOA ns0.directnic.com. hostmaster.directnic.com. 1384545543 28800 14400 604800 3600
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0