554 5.1.8 Email Outgoing Blocked

554 5.1.8 Email Outgoing Blocked

Hi,

We are unable send email (outgoing) through zoho desk with error 554 5.1.8 Email Outgoing Blocked. <a href=https://www.zoho.com/mail/help/usage-policy.html target=_blank>

Priorly we just send blasting email to our customer, is there our account blocked due to this activity ?