dns1.rr.com has no MX records.
Question and response
Question
dig dns1.rr.com. MX
Answer
The response has no answer records.
Authority
rr.com. 3600 SOA dns1.rr.com. hostmaster.charter.com. 2025060044 43200 3600 2419200 3600
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0