ns7.smartclickonline.com has no MX records.
Question and response
Question
dig ns7.smartclickonline.com. MX
Answer
The response has no answer records.
Authority
smartclickonline.com. 86400 SOA ns6.smartclickonline.com. yod.yod.net. 2026021903 3600 1800 1209600 86400
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0