Unable to send email

[Robert##]

Following Message received 

Server error: '453 4.1.1 aZEArws7hPjGQ Too Many Recipients (TT501)'

I can receive emails but not send due to error above

I have another email with talktalk which is working fine for sending and delivery

[Gondola]

Hi Robert

The error message indicates a temporary stop on sending because the mailbox has been detected as sending to more than the expected number of recipients in the hour before the error.

Wait an hour and the stop on sending will be relaxed.