Hi, Rob
SmarterMail actually does include the ability to create a filter for times when your address is in the CC field. If you have an existing filter for when you're address is in the To field, you can simply modify that rule for when your address is in the To OR the CC field. You could also create a new rule if you like. This option is in the To Address section when creating or editing a filter.
I hope that helps.
Derek Curtis
COO
SmarterTools Inc.
www.smartertools.com