tie.simsamexico.com has no MX records.
Question and response
Question
dig tie.simsamexico.com. MX
Answer
The response has no answer records.
Authority
simsamexico.com. 3600 SOA dns.simsamexico.com. hostmaster.simsamexico.com. 1796838953 43200 3600 604800 3600
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0