Now, here’s how to delete a conversation:
- Select the message in the Reading pane.
- Click the Home tab, and click Ignore in the Delete group, or press [Ctrl]+[Delete], or right-click the message and choose Ignore from the resulting context menu.
- Click Ignore Conversation.
This will remove all emails belonging to this conversation from your Inbox (or folder) and Outlook will automatically detour new messages in that conversation.
The conversation can easily be reclaimed if you don't have the permanently delete all items in the "Deleted Items" folder when closing option turned on:
- Select the Deleted Items folder.
- Select any message in the conversation that you want to recover.
- Click Ignore in the Delete group.
- Click Stop Ignoring Conversation.
When you stop ignoring a conversation, Outlook will move all messages in the conversation back to your Inbox. In addition, you’ll start seeing new messages in your Inbox as they arrive.