nagios.mclaut.net has no MX records.
Question and response
Question
dig nagios.mclaut.net. MX
Answer
The response has no answer records.
Authority
mclaut.net. 600 SOA ns1.maklaut.lv. hostmaster.2mcl.com. 2014052526 10800 3600 1209600 10800
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0