NOTE: This version of Outlook is no longer supported and it is recommended that you update to the latest version.
To unclutter your emails by Conversation using Outlook 2010, follow these steps:
1. Open Outlook 2010
2. Select View then choose Show as Conversations
3.You will be prompted to choose either: This Folder, or All Folders.
4. Delete or Archive Conversations that you no longer wish to keep.