The default view in Outlook 2010 can be overwhelming if you receive a lot of mail. One option which most modern mail clients have adopted, is conversation view, where we group all mail that is related so it reads like a conversation.
Switching To Conversation View
Fire up Outlook and head over to the View tab.
Here you will quickly come to see the Show as Conversations check box.
Choose to show all your folders as conversations.
That’s all there is to it.