You can only have one filter definition assigned to automatically run for an account, but that definition can contain many individual rules.

Think of a filter definition as a book of actions you want to run against your messages. Just as a book contains multiple chapters that may cover different topics, a filter definition contains multiple rules that can look for different patterns and take different actions.

For many people, a single filter definition will be enough to filter their incoming mail. For more complex mail filtering though, you can create a separate filter definition for each account. You can even have a filter rule in a definition that, if triggered, activates another filter definition for the message currently being filtered.

The basic process for creating your filters is as follows:

• Create a Filter Definition
• Create the rules you want to use inside of the definition. Keep in mind that the order that the filters execute is critical.
• Save the definition with your rules in it.
• Assign the definition to the desired account(s) by right-clicking on the account in the account list, select Enable Filter and then select the Filter Definition from the context menu.