Able to Send mail but not receive any mail, issue of domain and sub domain

Able to Send mail but not receive any mail, issue of domain and sub domain

I am facing some difficulty due to domain subdomain.

On my website is hosted on the domain robobionics.cuccfree.com and have used the same to configure zohomail.

When setting the MX records I cannot add it to the same domain but have to point it to robobionics.cu.cc

Due to the above I am able to send mails but not receive any.