cp.serverdata.net has no MX records.
Question and response
Question
dig cp.serverdata.net.cdn.cloudflare.net. MX
Answer
cp.serverdata.net.cdn.cloudflare.net. 300 CNAME controlpanel.gslb.serverdata.net.
Authority
The response has no authority records.
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0