Outlook 2010 email account sending double emails automatically

1. Account Settings

2. Email Tab

3. More settings

4. Sent Items tab

5. Select "save sent items in sent folder on this computer"

6. Click OK

7. problem fixed



source: http://social.technet.microsoft.com/Forums/en/outlook/thread/8378baff-8c5a-47bc-90a6-8f9c61b2b394