Outlook’s integrated Clean Up tool removes messages from your email folders that you no longer need.
Remove redundant messages from your Inbox (or any other email folder), select Home>Clean Up
1. On the Home tab, in the Delete group, click Clean Up.
2. Click one of the following:
• Clean Up Conversation – The current Conversation is reviewed, and redundant messages are deleted.
• Clean Up Folder – All Conversations in the selected folder are reviewed, and redundant messages are deleted.
• Clean Up Folder & Subfolders – All Conversations in the selected folder and any folder that it contains are reviewed, and redundant messages are deleted.
Change Conversation Clean Up Options:
1. Click the File tab.
2. Click Options.
3. Click Mail.
4. Under Conversation Clean Up do any of the following:
• You can change the folder where items are moved, for Cleaned-up items will go to this folder, click Browse, and then select an Outlook folder. By default, messages are moved to the Deleted Items folder. If you have multiple email accounts in your Outlook profile, each account has its own Deleted Items folder. Messages are moved to the Deleted Items folder that corresponds to the email account.
• Note: This option is not available if the destination is Deleted Items folder: To replicate the folder structure of items Clean Up deletes (when you use the Clean Up Folders & Subfolders command), select When cleaning sub-folders, recreate the folder hierarchy in the destination folder.