Duplicate emails in Outlook 2010

Applies to: Microsoft Outlook 2010Outlook 2010 with Business Contact Manager

Resolution


If you're receiving duplicate emails, start at the top of the list below and work your way down. We’ve listed the most common cause first and worked our way down to the least common cause. If something jumps out at you, by all means go there first. 


If you have a large amount of mail, store copies of it on the server and have Outlook check for new mail every few minutes, there's a good chance you will get duplicate email. Outlook will never complete a check mail pass before the next one starts, this prevents Outlook from marking the mail as downloaded. Try extending the time interval that Outlook checks for mail:
  1. Click File > Options > Advanced.
  2. Scroll down to the Send/Receive section and click Send/Receive.
  3. Set the time interval for "Schedule an automatic send/receive every" XX Minutes to 15 minutes or more. A very large amount of mail on the server may require more time (Screen shot for this step is listed below).