Unable to send message;Reason:553 Relaying disallowed. Invalid Domain - admin@projexiveng.com

Unable to send message;Reason:553 Relaying disallowed. Invalid Domain - admin@projexiveng.com

Hello Team,
When I try to send mail through ZOHO mail I am getting the following error.

"Unable to send message;Reason:553 Relaying disallowed. Invalid Domain"

Can I get some help on this?

Thanks