Unable to send message;Reason:550 5.4.6 Mail rate exceeded limit

Unable to send message;Reason:550 5.4.6 Mail rate exceeded limit

Hello, 

I am trying to send emails to some groups of people but I receive this message.
Does it mean I have to resend the emails, or that the receiver shall receive the first blocked email at some point ?
Can you please help unblocking it : my email address is chloecosmidis@asialyst.com

Thanks,
Chloe
Unable to send message;Reason:550 5.4.6 Mail rate exceeded limit