MAIL AND ADDRESS BOOK

Stopping mail rule processing
When you define a series of mail rules, the rules execute in order. You can use a "stop processing" action when you set up mail rules, to stop the processing of all rules following the rule that contains the "stop processing" action. You can use the "stop processing" action alone, that is, as the only action in a mail rule, or you can use it with another action in a rule. Whether "stop processing" is one of a series of actions or one of a series of rules, no further action is taken after "stop processing" is encountered. The "stop processing" rule is especially useful when more than one rule could apply to a message, but you want execution of mail rules to stop after the first action is executed. For example, you can define the following rules:
In this example, if the subject line contains the subject "Marketing and Sales," the message is moved to the Marketing Information database, and then all rule processing stops. If the "stop processing" action is not present, the message is first moved to the Marketing Information folder, and then moved to the Sales Information folder when the second rule executes.

For more information on creating mail rules, see Filtering new mail using rules.