ns.suscom-maine.net has no MX records.
Question and response
Question
dig ns.suscom-maine.net. MX
Answer
The response has no answer records.
Authority
suscom-maine.net. 900 SOA ns.suscom-maine.net. dnsmaster.comcastonline.com. 2008104020 7200 300 604800 900
Additional
. 0 OPT ; payload 4096, xrcode 0, version 0, flags 0