mail.ancintl.com has no MX records.
Question and response
Question
dig mail.ancintl.com. MX
Answer
The response has no answer records.
Authority
ancintl.com. 3600 SOA ns.gabia.co.kr. hosting.gabia.com. 2021011108 1800 600 1209600 86400
Additional
. 0 OPT ; payload 4096, xrcode 0, version 0, flags 0