sitecatalyst.com.mx has no MX records.
Question and response
Question
dig sitecatalyst.com.mx. MX
Answer
The response has no answer records.
Authority
sitecatalyst.com.mx. 300 SOA exfer-vip-01.corp.adobe.com. hostmaster.adobe.com. 9 10800 900 2419200 300
Additional
. 0 OPT ; payload 4096, xrcode 0, version 0, flags 0