mail.haeahn.com has no MX records.
Question and response
Question
dig mail.haeahn.com. MX
Answer
The response has no answer records.
Authority
haeahn.com. 300 SOA name.haeahn.com. hostmaster. 956 600 300 86400 600
Additional
. 0 OPT ; payload 4000, xrcode 0, version 0, flags 0