Clients with the BorderScout Anti-Spam-Anti-Virus email filtration system can login and configure their scanning preferences, and maintain their blacklists/whitelists and quarantine.
Sign up for a BorderScout account http://secure.clara.net/asav/
Single users login: http://borderscout.uk.clara.net/login.cgi
Clients who have purchased multiple BorderScout licenses can choose which email addresses they wish to protect: http://secure.clara.net/asav/manage.php