Tap a conversation that contains the message you want to read.
The conversation opens to the first new (unread) message, or to the first starred message, if you’ve previously starred a message in the conversation.
Tap to set labels for the message to help organize your messages.
While viewing a message, tap the message action icons on the message header to access options which include to mark it as a favorite, to reply to the sender, and to access Reply all to reply to all addresses and Forward to forward the message to someone else.