dominios2.bancolombia.com.co has no MX records.
Question and response
Question
dig dominios2.bancolombia.com.co. MX
Answer
The response has no answer records.
Authority
bancolombia.com.co. 3600 SOA dominios2.bancolombia.com.co. dominios.bancolombia.com.co. 764372607 1200 180 1209600 3600
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0