If we would add that action to the first rule and the rule applies to a received message, the action “stop processing more rules” will prevent that the second rule will be executed as well. The way to prevent this, is to add the action “stop processing more rules” to the rule. Now imagine that you receive an e-mail from me where I have the word Outlook in the subject both rules with apply! So it will get moved out of the Inbox two times and thus create a duplicate.

Apply this rule after the message arrives.

In this example there are two rules configured The following example will show how this can lead to duplicates. This is because for each e-mail received, Outlook will fire all configured rules against it. Rules, and more specific “Move to folder” rules, is the most easiest one to get yourself some duplicates. This article discusses the most common configuration issues which lead to e-mail duplication and how to prevent them from happening again.

Actually, I’m not talking about just a single e-mail here but basically all your e-mails and not just twice but LOTS of times.

It’s probably one of the most annoying things receiving the same e-mail multiple times.

Delete duplicates in outlook 2003