Blocking an email address from sending

Is there a way to block an address on the server from sending, using exim? For example, we have the domain test.com on our servers. We want to prevent clockwork@test.com from sending messages. Is there some place that we can put

clockwork@test.com

So that it is not a valid mail from candidate? We have pop before smtp authentication, but it does not seem to be working. I checked the logs, and it is numerious IPs that are using this address to send messages.

Any help would be appreciated.

 

 

 

 

Top