antispam.da.net.tw has no MX records.
Question and response
Question
dig antispam.da.net.tw. MX
Answer
The response has no answer records.
Authority
da.net.tw. 1800 SOA aspen.ns.cloudflare.com. dns.cloudflare.com. 2396093390 10000 2400 604800 1800
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0