black.riverwatcher.com has no MX records.
Question and response
Question
dig black.riverwatcher.com. MX
Answer
The response has no answer records.
Authority
riverwatcher.com. 3600 SOA yellow.soltec.net. hostmaster.yellow.soltec.net. 1737098188 3600 600 86400 14400
Additional
. 0 OPT ; payload 1680, xrcode 0, version 0, flags 0