Unable to send email "553 Relaying disallowed. Invalid Domain"

Unable to send email "553 Relaying disallowed. Invalid Domain"

Hello,

My domain recently expired and I renewed it, but now I am receiving the following 553 error when attempting to send email through my Zoho address:

"553 Relaying disallowed. Invalid Domain"

The domain name in question is "spitalmotru.ro"

Thank you!