Se ainda não o fez, consulte MS KB892240 - "Depois de configurar uma ou mais regras de mensagens somente de cliente no Outlook, outras regras de mensagens não são efetivadas ":
Symptom: After you configure one or more client-only message rules in Microsoft Office Outlook 2007, Microsoft Office Outlook 2003, Microsoft Office Outlook 2002, or Microsoft Office Outlook 2000, other message rules that you have configured in Microsoft Outlook do not take effect when you receive an e-mail message.
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This issue occurs if all the following conditions are true:
- You create a client-only message rule.
- In the client-only message rule, you click to select the stop processing more rules check box on the What do you want to do with the message? page of the Rules Wizard.
- The client-only message rule appears ahead of the server-side rules in the Rule (applied in the order shown) list on the E-mail Rules tab of the Rules and Alerts dialog box in Outlook.
When a rule that contains a client-only condition appears in the Rule (applied in the order shown) list in Outlook, and if this rule has the stop processing more rules check box selected, none of the server-side message rules that appear after this client-only rule are triggered. Exchange Server cannot evaluate the client-only rule condition. Therefore, Exchange Server cannot determine whether to process the remaining server-side rules.