smtp13.wmfi.net has no MX records.
Question and response
Question
dig smtp13.wmfi.net. MX
Answer
The response has no answer records.
Authority
wmfi.net. 600 SOA ns.cgi.com. dnsops\.gto.cgi.com. 790300840 1200 180 1209600 3600
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0