550 5.4.6Mail rate exceeded limit

Hello there,

Just transfered our e-mails on Zoho, but when sending e-mails we have the following problems:

Technical details of permanent failure:
Google tried to deliver your message, but it was rejected by the relay smtp.zoho.com [165.254.168.48].

The error that the other server returned was:
550 5.4.6Mail rate exceeded limit

The e-mail is contact@proconstructo.ro.

Hope to unblock the situation soon.

Thank you for your support.