The spam filter that we are using can be applied to an individual mailbox, domain, or range of users. The filters are applied by using RegEx expressions to determine which users to apply them to. By default these are not turned on because we do not want to force it on users. In the next version of the email configuration GUI there will be a setting that you can turn it off and on per mailbox, etc. If you would like to turned on now please just email
Support@ChangeIP.com with your username and which mailboxes you'd like to have it applied to.
The spam filter we are using is from
http://www.2150.com/regexfilter/ - we have had very good luck using this. Typically we catch about 99% of spam and have only had 1-2 false positives with the thousands of users that we host.