Not able to use zoho email service

Not able to use zoho email service

Hi! 
I recently registered with zoho with my email  smartways.omproptech@gmail.com and was trying to use zoho email service for my domain  omproptech.com but it is showing me error that the domain is already associated with some another account . pls help me to get over this problem and use the email service .

Regards,
- Team Smartways