rcncustomer.com has no MX records.
Question and response
Question
dig rcncustomer.com. MX
Answer
The response has no answer records.
Authority
rcncustomer.com. 86400 SOA master.dns.rcn.net. hostmaster.rcn.com. 2026022101 10800 3600 604800 86400
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0