Change options for viewing messages in Conversations
With the Conversations arrangement view, you can customize how you view messages in the message list. For example, when you’re viewing a Conversation in the Inbox, you can exclude messages saved in the Sent Items folder and that you moved to other folders. Or, you can change the settings so the full Conversation appears without clicking to expand it.
Click View > Conversation Settings.
Note If the Conversation Settings command is grayed out, first check the Show as Conversations box.
Click the option you want.
Show Messages from Other Folders includes messages from the Sent Items folder. If you want to see full Conversations without expanding them first, click Always Expand Selected Conversations.