This depends upon what you are trying to connect with. If you have been blocked, you should get an error message telling you that you have been blocked. But this may not be obvious, depending upon what software you are using. Symptoms of being blocked include not being able to connect to any service on the server at all, with it timing out.
If you are unsure, please go to your own web site, or www.sirium.net , and you should get an error page telling you that you have been blocked.