Unable to send message reason 550 5.4.6 unusual sending activity detected please try again after some time

Unable to send message reason 550 5.4.6 unusual sending activity detected please try again after some time

Hello

I'm unable to send any emails because I keep getting this error

Unable to send message; Reason:550 5.4.6 Unusual sending activity detected. Please try after sometime

I have literally sent less than 10 emails today

I'm not sure why I'm getting this