custommail.hyperoffice.us has no MX records.
Question and response
Question
dig custommail.hyperoffice.us. MX
Answer
The response has no answer records.
Authority
hyperoffice.us. 1800 SOA curitiba.ns.porkbun.com. dns.cloudflare.com. 2396349070 10000 2400 604800 1800
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0