customers.intelcom.online has no MX records.
Question and response
Question
dig customers.intelcom.online. MX
Answer
The response has no answer records.
Authority
intelcom.online. 3600 SOA isp.24hc.ru. info.itcom.info. 2019122113 3600 3600 604800 86400
Additional
. 0 OPT ; payload 4096, xrcode 0, version 0, flags 0