How can I create a rule to file sent messages in a specific folder without also keeping a copy in the Sent Items folder?
A Rules Wizard rule lets you file outgoing items in a specific folder, but the rule doesn't override Outlook's default setting to file outgoing messages in the Sent Items folder. If you don't want items to appear in both the Sent Items and specified folders, you can create a rule to override the Sent Items setting.
Figure 1 shows the Rules Wizard rule that directs Outlook to file items you send to a particular recipient in a related folder. When you configure this rule, be sure to select the stop processing more rules check box. Next, create another rule to handle all other outgoing messages. This rule should look like this:
Apply this rule after I send the message
move it to the Sent Items folder
This last rule must appear below all rules that file sent items in specific folders. Outlook applies rules in the order in which they appear in the Rules Wizard list. If a message doesn't meet the criteria of any of your rules for sent mail, it "falls through" to this last rule, which directs the message to the Sent Items folder. Adding the stop processing more rules action to rules that direct messages to specific folders ensures that these messages bypass the final rule for Sent Items.
When your rules are in place, you can turn off Outlook's default Sent Items behavior. Choose Tools, Options, E-mail Options, then clear the Save copies of messages in Sent Items folder check box, as Figure 2 shows.