antispam.mundivox.com has no MX records.
Question and response
Question
dig antispam.mundivox.com. MX
Answer
The response has no answer records.
Authority
mundivox.com. 300 SOA ns-rj-1.mundivox.com. ti.mundivox.com. 2026020301 7200 3600 1209600 4320
Additional
. 0 OPT ; payload 4096, xrcode 0, version 0, flags 0