Getting Expected response code 250 but got code "550" errors

Getting Expected response code 250 but got code "550" errors

I just setup my zoho email and within a few minutes im not able to send any emails.

here is the error im getting

Email to email@example.com failed: Expected response code 250 but got code "550", with message "550 5.4.6 Unusual sending activity detected. <a href=https://www.zoho.com/mail/help/usage-policy.html target=_blank>Learn more.</a> To unblock <a href=https://mail.zoho.com/UnblockMe target=_blank>Click here.</a> "