View e-mail messages by conversation
When you arrange messages by conversation, messages in a folder that share the same subject appear together in the message list. The messages within each conversation are sorted with the newest message on top. When a new message is received, the entire conversation moves to the top of your message list.
Icon for a collapsed conversation
Icon for an expanded conversation
Icon for unread message
Do any of the following:
Read messages that are part of a conversation
Turn off viewing by conversation