A set of rules can include any number of individual rules, and you can add new rules to a folder as you need.
- Hover over a folder with rules applied (indicated by the icon) and click More then Manage Rules.
Click New Rule.
On the New Rule page you can add a new rule to a set of rules in exactly the same way as the first time you created a rule, see creating a rule.
After creating the last rule you return to the Rules page. Any new rules created are added at the end of the rule set.