cptxoffice.net has no MX records.
Question and response
Question
dig cptxoffice.net. MX
Answer
The response has no answer records.
Authority
cptxoffice.net. 1800 SOA gene.ns.cloudflare.com. dns.cloudflare.com. 2394551401 10000 2400 604800 1800
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0