VOD.rcn.net has no MX records.
Question and response
Question
dig VOD.rcn.net. MX
Answer
The response has no answer records.
Authority
vod.rcn.net. 7200 SOA master.dns.rcn.net. hostmaster.rcn.com. 2025082001 10800 3600 604800 86400
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0