Remove Duplicate
Messages

Remove Duplicate Messages removes duplicate messages from the current selection in Apple Mail. The script determines whether a message is a duplicate of another message by examining these message headers:

• MessageID
• Subject
• From
• Date

If these message headers match another message in the view, the script flags the message as a duplicate and removes it from Mail.

The script displays interactive dialog boxes that allow you to specify whether you want duplicate messages to be removed or retained, optionally prompting you for each duplicate message it encounters while scanning. You can also instruct the script to save all duplicate messages to an archive folder on disk before they are removed.

This script is provided with source code so that you may edit the script as you see fit. Read the included instructions for more information.

• Fixed a bug introduced in version 1.3.4 where the script would generate an error and abort processing when encountering messages that were "On My Mac" and therefore had no associated Mail account. Thanks to David Jacobson and Michelle Wilson for reporting this issue.
• Added a "Quit" button to the interactive dialog box that asks if you would like to remove a duplicate message (displayed when you click the "Ask Me" button the Remove Action dialog when you first start the script). Clicking this button allows you to abort processing before the script has finished processing all of the selected messages. Thanks to Lorenzo Cangiano for the suggestion for this feature.
• Rearranged buttons in interactive dialog boxes to improve usability and changed default button in Remove Action dialog box to "Ask Me".