calliope.zivver.com has no MX records.
Question and response
Question
dig calliope.zivver.com. MX
Answer
The response has no answer records.
Authority
zivver.com. 1800 SOA dora.ns.cloudflare.com. dns.cloudflare.com. 2397112855 10000 2400 604800 1800
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0