ns1.usatfus.about.us has no MX records.
Question and response
Question
dig ns1.usatfus.about.us. MX
Answer
The response has no answer records.
Authority
about.us. 600 SOA pdns1.ultradns.net. sec_grp.neustar.com. 1298801758 10800 3600 604800 600
Additional
. 0 OPT ; payload 4096, xrcode 0, version 0, flags 0