1.    Enter SPAM Expert dashboard via client area. If user is not familiar with 

       this then may refer to the below guideline:

      (How To Enter SPAM Expert Dashboard) Please click here. 

2.    Once enter, click on "Sender Blacklist" button under "Whitelist/Blacklist" session.

3.    Key in the email address or hostname that you with to blacklist in the Sender box. 

4.    Click on "Add" to whitelist the email address / hostname.