Mail rate exceeded limit

Mail rate exceeded limit

Dear Support,

I have send  email through ueo@u-labo.co.jp

Now i am getting below message. 

Unable to send message;Reason:550 5.4.6 Mail rate exceeded limitClick here to unblock.

Please Unblock my account
.
And we will pleased if you tell us how to
deal with this case in future.

Thanks
Yoshiko Ueo