contactel.net has no MX records.
Question and response
Question
dig contactel.net. MX
Answer
The response has no answer records.
Authority
contactel.net. 86400 SOA ns.contactel.cz. hostmaster.cz.net. 2014072303 28800 7200 604800 86400
Additional
. 0 OPT ; payload 4096, xrcode 0, version 0, flags 0