Removal is the second step to eradicating the duplicates. How to prevent seeing duplicate names when viewing the “Select Names” window after clicking “To:” How to prevent sending duplicate email messagesģ. How to stop receiving duplicate email messagesĢ. Preventing them from occurring in the future is the first step to eradicating them.ġ.

Many things cause duplicates to appear, including synchronization with phones, restoring Exchange public folders from backups, incorrect Outlook rules and many other reasons. So this page is broken up into two parts: how to prevent the duplicates from occurring in the first place and then how to clean up the mess.

The best way to prevent and remove Outlook duplicates is with a divide-and-conquer strategy. To find out more see our FAQ, including how to find out which Outlook version is installed. All of the information contained pertains to Microsoft Outlook, the desktop client. This page contains answers to common problems about how to prevent and remove Outlook duplicates, where they come from, and how to avoid them.